Back in a Lotus - 2006 Exige S
Discussion
mattdavies said:
Really enjoy reading your updates.
Will follow with interest how you get on with the EMU black as i am looking at the same ECU for a potential future upgrade. Be interesting to know if it can do torque reduction between gears.
Cheers Matt, yes apparently it can do torque by gear but we'll see how that looks in practise. We also talked about having two maps too, so potentially an 'unleashed' one and then one which keeps the torque in check across 3rd and 4th... but in the real world I'm not sure how different they would end up being! I'm still sort of relying on my 440cc injectors to keep me pegged back to somewhere sensible.Will follow with interest how you get on with the EMU black as i am looking at the same ECU for a potential future upgrade. Be interesting to know if it can do torque reduction between gears.
If/when the gearbox restriction is lifted it would only be a case of some 550cc injectors and slightly smaller pulley and the car should be good for 300bhp, at which point the SC is starting to run out of puff so is probably a realistic ceiling target.
wevster said:
Really enjoying this thread.
I actually didn't know about Track Torque until this thread, I took my car in for a Geo last week and I m pleased with the results, it nice to have found somewhere not to far away who I can trust.
They're a good bunch, quite lucky to have them so local. They did a lot of the setup work on my Subaru and I've always had most fun/success out of their setups on the Lotus too - so should probably stop going elsewhere as often as I do!I actually didn't know about Track Torque until this thread, I took my car in for a Geo last week and I m pleased with the results, it nice to have found somewhere not to far away who I can trust.
Anyway, moving on:
Dropped the gearbox oil and engine oil this weekend, well that took an hour - and then thoroughly degreasing my floor, underside of my car and pretty much all of my possessions (including the cat) to get rid of the gearbox oil smell took the rest of the time up...
Here's my new drain plug for the gearbox:
Sensor is just cabletied up out of the way for now, but once the EMU goes in I'll have it hooked up and reporting gearbox oil temps. Based on what I see will influence what happens next, but I'm fully expecting to be dropping the oil again in the near future for an oil cooler install. If anyone has any pictures of a gearbox cooler install, I welcome the inspiration for packaging/positioning etc.
While I had the car up in the air and I was making a mess I decided to tidy up an element of the charge cooler install.
I previously had the pump mounted along the bulkhead trim which was nice and tidy and made for a short wiring run.
The downside to this was that the lowest 'drain point' I had at the rear of the car was essentially the header tank - meaning any work on the charge cooler system just made a massive mess, filling my alternator with 5 litres of coolant isn't something I wanted to be doing too often... Clearance between the pump and SC was also very tight so I was a bit nervous about engine movement damaging the pump (lack of witness marks suggests that wasn't an issue in hindsight).
I also had a bit of a window rattle at certain RPM, so I had half a suspicion that the pump was causing it.
As an alternative location there's loads of room in the side pod/rear wheel arch area so I thought by moving it down there I could retain easy access for maintenance but also give me a convenient place to drain the system if I need to.
I had to extend the wiring a bit, but no big deal there (as you can see I over extended it a bit...). Conveniently there was a clam fixing bolt right in a good place for a p-clip on one of the hoses, so made use of that.
The good side to this, my window rattle did indeed get fixed - so pretty chuffed with that. The downside is that the whine from the pump became very audible all of a sudden, not helped of course by the fact the pump was effectively mounted to my lug 'ole. You could just about hear the pump over the engine idle and it only took a short drive to get annoyed by that.
Luckily the fix was an easy one, I picked up some M6 isolation bobbin things and mounted the pump via one of those. The pump is now inaudible with the engine running, and has the added benefit of adding clearance between the hoses and the bodywork.
Pump can now be unbolted/drained from the side pod if needed (don't tell the local chavs that).
Whilst messing around with my chargecooler plumbing I noticed something odd with the nose bracket on the supercharger, in that it didn't seem to be attached to anything.
It's really well hidden and incredibly hard to see without sticking your head in the sidepod, but I snapped a photo with my endoscope:
I initially assumed there should be a small bracket between this bracket and the alternator, but thanks to confirmation from Dave @ SeriouslyLotus I realised the alternator must have swung down from its proper position. Luckily the belt tensioner must have taken up this slack in its stride, but certainly this wasn't right.
With the car jacked up and sidepod off I got a better look.
Fix is a cheap one, M8x45mm bolt and a 15mm nylon spacer.
Oh, and loctite...
When I took the belt off the alternator, it had no free movement in it at all - so it wasn't flapping around around the axis of it's one remaining bolt - but I guess the strain on the belt had gradually over time pulled the alternator down to the point where it can't go any further (as there's engine in the way) which probably aided the tensioner in gradually taking up the slack. Had this suddenly have flapped down I'm sure I'd have lost a belt at some point in history.
I loosened off the bottom bolt and it was fairly easy to slot the spacer/bolt in and tighten everything back up again.
Getting the belt back on was much harder than I remember from previous jobs, so I'm certainly working the tensioner harder now! How this came to happen I'm really not sure, it's such a hidden area of the engine bay that I probably don't have any old photos to check back on (though I will check...!). The car did get a new supercharger back in 2012, the circumstances around that I'm really not sure but perhaps it was never fitted properly? Or on the other hand the bolt could have fallen out last week, I really can't be sure.
It's really well hidden and incredibly hard to see without sticking your head in the sidepod, but I snapped a photo with my endoscope:
I initially assumed there should be a small bracket between this bracket and the alternator, but thanks to confirmation from Dave @ SeriouslyLotus I realised the alternator must have swung down from its proper position. Luckily the belt tensioner must have taken up this slack in its stride, but certainly this wasn't right.
With the car jacked up and sidepod off I got a better look.
Fix is a cheap one, M8x45mm bolt and a 15mm nylon spacer.
Oh, and loctite...
When I took the belt off the alternator, it had no free movement in it at all - so it wasn't flapping around around the axis of it's one remaining bolt - but I guess the strain on the belt had gradually over time pulled the alternator down to the point where it can't go any further (as there's engine in the way) which probably aided the tensioner in gradually taking up the slack. Had this suddenly have flapped down I'm sure I'd have lost a belt at some point in history.
I loosened off the bottom bolt and it was fairly easy to slot the spacer/bolt in and tighten everything back up again.
Getting the belt back on was much harder than I remember from previous jobs, so I'm certainly working the tensioner harder now! How this came to happen I'm really not sure, it's such a hidden area of the engine bay that I probably don't have any old photos to check back on (though I will check...!). The car did get a new supercharger back in 2012, the circumstances around that I'm really not sure but perhaps it was never fitted properly? Or on the other hand the bolt could have fallen out last week, I really can't be sure.
ECU/Mapping update!
I collected the car on Saturday and although I've had very little time in the car, I can at least report on some bits! First off a note on RRR Engineering, very professional from the beginning with good communication, time/booking management and generally just see well organised. All attributes which are not as common as they should be in the car tuning world...
We agreed up front for the to have the car Saturday to Saturday, makes the logistics easier for me and allows them to do proper cold start tuning etc. Other than bolting in the ECU and mapping, I also asked them to supply and fit the ECUMaster EDL1 data logger unit and wire in my gearbox oil sensor that I recently added to the drain plug.
On handover data Roberto was happy to chat for ages about my plans/trajectory for the car and discussed any gremlins I felt the car already had.
By end of Monday they had benchmarked the car with its 'as-is' setup just to make sure I didn't piss fuel/coolant/oil all over their workshop and the results came back as expected of "260ish". This matches my butt dyno opinion that neither charge cooler or 2bular system added much of anything on the 260 ECU.
By end of Wednesday the new ECU was in and the base map setup, I got a cagey e-mail back saying "yada yada hottest day of the year, intake temps, small power gain" etc but that they intended to do proper power tuning early on thursday.
I got some results by midday and they sounded both wrong and terrifying. I was told the car was doing "276ish at the hubs". AT THE HUBS.... factoring in 15% or so for transmission losses that would put my pub figure way into the 300s, a figure that I was almost certain my hardware wasn't capable of (stock pulley and 440cc injectors). I queried it of course, but there was only so much I could argue without sounding like an internet know-it-all so I just let it lie, and assumed there was a terminology mixup and that the car made 276 AFTER loss adjustment, which is much more in line with expectations. They even said "276 at the hubs so will be 320+ at the fly", so it's not just me mishearing terminology!
My main fear was that if by some miracle they did get 320+ out of it, gearbox would go from marginal to flat-out suicidal. I've already paid for a gearbox upgrade in my head, so I'm comfortable with it happening eventually... but not imminently!
A few hours later the final figure came in of 280bhp, again quoted at the hubs and this time printed on a graph.
I know from a recent posting of a RRR graph from another Lotus owner that their graphs are usually posted 'at the hubs' which added up to what I was told verbally, but there are a couple of giveaways that suggest it has indeed been adjusted and is actually 280bhp ATF.
1) you can see the original benchmark run on it which is around 260bhp, if these were at the hub figures that would have been more like 215-220bhp.
2) the torque figure appears to be pre-adjustment (at the hub). Suggesting maybe BHP has been adjusted but torque has not?
In any case, this is probably just a comms hiccup between the guy doing the dyno/map and the guy communicating with me. If they usually do dyno graphs pre-adjustment then it's understandable that he would relay that info to me as such.
Anyway, none of that is really important in the end - I was expecting mid 270s, so 280bhp is a result and is right on my imaginary threshold for the gearbox. I fully expect it to fail at some point, but I think I'd be unfortunate for it to go bang immediately. We'll see eh.
After giving myself a panic induced headache at the thought of a 320bhp C64-eater, I decided to just see how the car drives and then take it from there.
Ignoring the figures, the torque curve looked promising, as it went from a hill to more of a ramp steadily increasing up to the limiter. In both BHP and torque the midrange from the benchmark run yielded minimal improvement, so perhaps the CC/Exhaust can take some credit for that - but the new map added clear gains low down and high up. Apparently the 440CC injectors peaked at 80% duty, so a nice safety net there - but any smaller on the pulley and 550's would be needed which matches what I expected.
On to collection day, had a quick walk around the car - paid my bills and hit the road just in time for the skies to open...
This basically meant I didn't go above 4k RPM until I beat the rain and got within 20miles of my house, 2 hours after collecting the car. :lol: Impressions on the A1 though were very positive, car had an urgency at low RPM that it certainly didn't have before, pulling round slower moving traffic in 6th felt great.
Once onto dryer roads I gave the car a handful of 'pulls' and was impressed with the result, the power delivery has always been linear but the tail-off of torque is something I never noticed before, but was definitely a feature in retrospect. The car now pulls rampantly all the way to the top, each gear feels like it's been "promoted" and I imagine 2nd gear will be all but redundant at all circuits now due to the potency of third and above. For the record my butt dyno would say its closer to 280ATF than it is 320bhp, so that puts that to bed.
Despite that positive start, I think there may be a bit of ironing to do. The car seems to have some issues at low RPM whilst coasting to a stop. I think I've mentioned it on the thread before, but even previously on the Lotus ECU I had issues with the car periodically stalling when coasting to a stop, the revs would dip below idle and the car would just die unless I was quick to poke the gas to revive it.
I did report that to RRR, and the EMU is clearly responding well to this - as I no longer stall, but the initial drop in revs is still happening, the EMU just jumps in and recovers it for me... so an improvement yes, but still feel there's a root issue somewhere, possibly mechanical or a vac leak maybe? Not sure if the DBW cars have an idle air control valve or something similar, but I'm sure I can do some homework and find some parts to dismantle.
Aside from that I noticed that revs are a little slow to fall when dipping the clutch in first gear, which makes the car feel a little 'clumsy' when not used to it. This may have been engineered in to mitigate against the stalling detailed above - but it's something I can discuss with RRR once I get some more mileage done.
I spent the rest of my weekend fiddling around with the ECUMaster software, and started playing with the logging. I'm going to LOVE this once the car gets back on track!
Gearbox temp sender seems to be working fine, and was logging temps of 79/80deg C all the way home. Temps didn't seem to leap up when the car is used enthusiastically like you would see with engine oil temps (or intake air temps) but I at least now have a benchmark, so can see how hot it gets on track.
Oh, quick note on traction control - for now the EMU is pretty much emulating the stock TC that I had, in that it's on or off - and that's about it. By RRR's own admission it's pretty agricultural and is certainly not suited for track use, but I have a couple of options for improving it if I want to:
1- Add a rotary switch at which point it becomes variable, perhaps I could find a sweetspot on a wet track in which it adds value. Again the logging stats for TC look really detailed, so would be interesting to see
2- Add some wheelspeed/CAN adapters and go full motorsport on it. Not sure exactly what that means, but almost certainly excessive for my use so probably something I won't bother with.
Unfortunately I won't be back in the car for a week or so, so need to wait to play with my toys later... :roll:
I collected the car on Saturday and although I've had very little time in the car, I can at least report on some bits! First off a note on RRR Engineering, very professional from the beginning with good communication, time/booking management and generally just see well organised. All attributes which are not as common as they should be in the car tuning world...
We agreed up front for the to have the car Saturday to Saturday, makes the logistics easier for me and allows them to do proper cold start tuning etc. Other than bolting in the ECU and mapping, I also asked them to supply and fit the ECUMaster EDL1 data logger unit and wire in my gearbox oil sensor that I recently added to the drain plug.
On handover data Roberto was happy to chat for ages about my plans/trajectory for the car and discussed any gremlins I felt the car already had.
By end of Monday they had benchmarked the car with its 'as-is' setup just to make sure I didn't piss fuel/coolant/oil all over their workshop and the results came back as expected of "260ish". This matches my butt dyno opinion that neither charge cooler or 2bular system added much of anything on the 260 ECU.
By end of Wednesday the new ECU was in and the base map setup, I got a cagey e-mail back saying "yada yada hottest day of the year, intake temps, small power gain" etc but that they intended to do proper power tuning early on thursday.
I got some results by midday and they sounded both wrong and terrifying. I was told the car was doing "276ish at the hubs". AT THE HUBS.... factoring in 15% or so for transmission losses that would put my pub figure way into the 300s, a figure that I was almost certain my hardware wasn't capable of (stock pulley and 440cc injectors). I queried it of course, but there was only so much I could argue without sounding like an internet know-it-all so I just let it lie, and assumed there was a terminology mixup and that the car made 276 AFTER loss adjustment, which is much more in line with expectations. They even said "276 at the hubs so will be 320+ at the fly", so it's not just me mishearing terminology!
My main fear was that if by some miracle they did get 320+ out of it, gearbox would go from marginal to flat-out suicidal. I've already paid for a gearbox upgrade in my head, so I'm comfortable with it happening eventually... but not imminently!
A few hours later the final figure came in of 280bhp, again quoted at the hubs and this time printed on a graph.
I know from a recent posting of a RRR graph from another Lotus owner that their graphs are usually posted 'at the hubs' which added up to what I was told verbally, but there are a couple of giveaways that suggest it has indeed been adjusted and is actually 280bhp ATF.
1) you can see the original benchmark run on it which is around 260bhp, if these were at the hub figures that would have been more like 215-220bhp.
2) the torque figure appears to be pre-adjustment (at the hub). Suggesting maybe BHP has been adjusted but torque has not?
In any case, this is probably just a comms hiccup between the guy doing the dyno/map and the guy communicating with me. If they usually do dyno graphs pre-adjustment then it's understandable that he would relay that info to me as such.
Anyway, none of that is really important in the end - I was expecting mid 270s, so 280bhp is a result and is right on my imaginary threshold for the gearbox. I fully expect it to fail at some point, but I think I'd be unfortunate for it to go bang immediately. We'll see eh.
After giving myself a panic induced headache at the thought of a 320bhp C64-eater, I decided to just see how the car drives and then take it from there.
Ignoring the figures, the torque curve looked promising, as it went from a hill to more of a ramp steadily increasing up to the limiter. In both BHP and torque the midrange from the benchmark run yielded minimal improvement, so perhaps the CC/Exhaust can take some credit for that - but the new map added clear gains low down and high up. Apparently the 440CC injectors peaked at 80% duty, so a nice safety net there - but any smaller on the pulley and 550's would be needed which matches what I expected.
On to collection day, had a quick walk around the car - paid my bills and hit the road just in time for the skies to open...
This basically meant I didn't go above 4k RPM until I beat the rain and got within 20miles of my house, 2 hours after collecting the car. :lol: Impressions on the A1 though were very positive, car had an urgency at low RPM that it certainly didn't have before, pulling round slower moving traffic in 6th felt great.
Once onto dryer roads I gave the car a handful of 'pulls' and was impressed with the result, the power delivery has always been linear but the tail-off of torque is something I never noticed before, but was definitely a feature in retrospect. The car now pulls rampantly all the way to the top, each gear feels like it's been "promoted" and I imagine 2nd gear will be all but redundant at all circuits now due to the potency of third and above. For the record my butt dyno would say its closer to 280ATF than it is 320bhp, so that puts that to bed.
Despite that positive start, I think there may be a bit of ironing to do. The car seems to have some issues at low RPM whilst coasting to a stop. I think I've mentioned it on the thread before, but even previously on the Lotus ECU I had issues with the car periodically stalling when coasting to a stop, the revs would dip below idle and the car would just die unless I was quick to poke the gas to revive it.
I did report that to RRR, and the EMU is clearly responding well to this - as I no longer stall, but the initial drop in revs is still happening, the EMU just jumps in and recovers it for me... so an improvement yes, but still feel there's a root issue somewhere, possibly mechanical or a vac leak maybe? Not sure if the DBW cars have an idle air control valve or something similar, but I'm sure I can do some homework and find some parts to dismantle.
Aside from that I noticed that revs are a little slow to fall when dipping the clutch in first gear, which makes the car feel a little 'clumsy' when not used to it. This may have been engineered in to mitigate against the stalling detailed above - but it's something I can discuss with RRR once I get some more mileage done.
I spent the rest of my weekend fiddling around with the ECUMaster software, and started playing with the logging. I'm going to LOVE this once the car gets back on track!
Gearbox temp sender seems to be working fine, and was logging temps of 79/80deg C all the way home. Temps didn't seem to leap up when the car is used enthusiastically like you would see with engine oil temps (or intake air temps) but I at least now have a benchmark, so can see how hot it gets on track.
Oh, quick note on traction control - for now the EMU is pretty much emulating the stock TC that I had, in that it's on or off - and that's about it. By RRR's own admission it's pretty agricultural and is certainly not suited for track use, but I have a couple of options for improving it if I want to:
1- Add a rotary switch at which point it becomes variable, perhaps I could find a sweetspot on a wet track in which it adds value. Again the logging stats for TC look really detailed, so would be interesting to see
2- Add some wheelspeed/CAN adapters and go full motorsport on it. Not sure exactly what that means, but almost certainly excessive for my use so probably something I won't bother with.
Unfortunately I won't be back in the car for a week or so, so need to wait to play with my toys later... :roll:
I got to play with the car a bit this weekend and unfortunately it resulted in a weekend in the garage taking bits apart and re-assembling them. 
I noticed an issue only obvious above 7500rpm in which there's a very harsh grinding/vibration sound.
https://www.youtube.com/watch?v=jx3nbPtpaxw
Needless to say this did not occur prior to having the ECU installed, but I'm not immediately pointing fingers at the ECU/Map as it's quite obviously a mechanical issue - and RRR have already reviewed the logs and found nothing scary that could explain it.
The issue occurs whether moving or stationary, whether in gear or neutral and becomes audible at 7.5k RPM on the button and remains until the redline, then falls away again once revs drop below 7500.
It's been a long weekend, but my troubleshooting process and list of things I've tried includes:
- Took Aux belt off to isolate all accessories and supercharger
- Took cat and backbox off to give them a shake, no obvious rattles
- Took charge cooler and cam cover off to check valvetrain for anything that looked particularly scary
- Dropped oil filter and inspected the oil.
- Checked ECU mounting
- Replicated with no undertray/diffuser attached
- Relocated my charge cooler header tank slightly as it was coming into contact with a solid breather hose
- Tightened everything I could find that could benefit from a tweak
- Cable tied everything I could find that was remotely flapping around
Still after all that, the rattle persists. I've tried having my missus rev it to 7.5k on axle stands while I poked around, but the car is so loud it's just impossible to pinpoint it before going deaf. Maybe in a larger garage up on ramps it may be easier.
Quite late on Sunday I bolted on the original ECU, probably should have done this sooner but the car ran a bit rough with it on as the factory O2 sensor has been removed - but it ran well enough to just about rev out to 7.5k which yielded no rattle. I don't consider this test conclusive though as the car was clearly not enjoying being revved that high with no O2 sensor and smelled VERY rich, so any harmonics in the engine bay would be totally different.
I was just about ready to give in for the weekend and I noticed a small trace of a wire-wool like material inside the tailpipe. Could be backbox material coming out suggesting some breakdown of the internal structure? (despite having no obvious rattle when shaking it). Seems like a long shot, but I've sourced a donor backbox to rule it out.
Failing that, my only remaining options really are to remove the manifold and just check it up close for cracks/leaks at the gasket - but I'd probably have smelled/noticed that already or seen trace of soot blasting out I guess. Finally I'll look to put in the factory O2 sensor and put the OEM ECU back in properly. If that absolutely cures it, then there must be something (god knows what) that's directly influenced by the map and ECU.
Not a great way to spend a weekend, but I've probably fixed a fair few rattles that I had beforehand
I noticed an issue only obvious above 7500rpm in which there's a very harsh grinding/vibration sound.
https://www.youtube.com/watch?v=jx3nbPtpaxw
Needless to say this did not occur prior to having the ECU installed, but I'm not immediately pointing fingers at the ECU/Map as it's quite obviously a mechanical issue - and RRR have already reviewed the logs and found nothing scary that could explain it.
The issue occurs whether moving or stationary, whether in gear or neutral and becomes audible at 7.5k RPM on the button and remains until the redline, then falls away again once revs drop below 7500.
It's been a long weekend, but my troubleshooting process and list of things I've tried includes:
- Took Aux belt off to isolate all accessories and supercharger
- Took cat and backbox off to give them a shake, no obvious rattles
- Took charge cooler and cam cover off to check valvetrain for anything that looked particularly scary
- Dropped oil filter and inspected the oil.
- Checked ECU mounting
- Replicated with no undertray/diffuser attached
- Relocated my charge cooler header tank slightly as it was coming into contact with a solid breather hose
- Tightened everything I could find that could benefit from a tweak
- Cable tied everything I could find that was remotely flapping around
Still after all that, the rattle persists. I've tried having my missus rev it to 7.5k on axle stands while I poked around, but the car is so loud it's just impossible to pinpoint it before going deaf. Maybe in a larger garage up on ramps it may be easier.
Quite late on Sunday I bolted on the original ECU, probably should have done this sooner but the car ran a bit rough with it on as the factory O2 sensor has been removed - but it ran well enough to just about rev out to 7.5k which yielded no rattle. I don't consider this test conclusive though as the car was clearly not enjoying being revved that high with no O2 sensor and smelled VERY rich, so any harmonics in the engine bay would be totally different.
I was just about ready to give in for the weekend and I noticed a small trace of a wire-wool like material inside the tailpipe. Could be backbox material coming out suggesting some breakdown of the internal structure? (despite having no obvious rattle when shaking it). Seems like a long shot, but I've sourced a donor backbox to rule it out.
Failing that, my only remaining options really are to remove the manifold and just check it up close for cracks/leaks at the gasket - but I'd probably have smelled/noticed that already or seen trace of soot blasting out I guess. Finally I'll look to put in the factory O2 sensor and put the OEM ECU back in properly. If that absolutely cures it, then there must be something (god knows what) that's directly influenced by the map and ECU.
Not a great way to spend a weekend, but I've probably fixed a fair few rattles that I had beforehand
A pretty hectic week of troubleshooting, the backbox issue turned out to be a dead end. It may well be blowing stuffing out, but that's not the cause of my rattle. I sourced a donor OEM one and ruled it out completely.
Next in the firing line was the new manifold, plan was to get it off the car and inspect for cracks etc. Manifold came off as new (as expected) but the gasket/flange situation was a bit ropey:
Some signs there of blowing, the gasket supplied with the 2bular kit was aftermarket so I compared it with a Toyota one I had lying around. Bore holes are oversized on the perforated one so that probably wasn't helping it seal.
Needless to say I refitted with the Toyota one, but rattle persisted.
Next up I took the cam cover off again, it's normally a 10min job on a 2ZZ but my chargecooler being sat on top of it and full of water complicates the process slightly, but still I wanted another look.
Took lift bolts out this time to make sure they hadn't broken in the holes, also poked at the chain guides with a stick to see if they were loose... nope, everything checked out. I did get a bit excited with the camcover itself though as I noticed it rattled a bit, but that turned out to just be the PCV valve...
I was about ready to give up, I arranged with a local specialist (Performance Autocare shout-out) who agreed to shuffle some stuff around and have a poke around with me, and also provided loads of out of hours support via e-mail on this issue - great service!
I settled in for a night in the house (for a change) and then a friend messaged me to say that my video "sounds like high lift cam is not activating". That reminded me of a video I'd watched a few days earlier in which a 2ZZ converted MR2 had the exact same sound as me at the exact same RPM range and his issue turned out to be lack of high profile cam activation...
Hmmmm.
I've experienced this rattle on the road and at load when I knew for sure I was on high lift cam, as you can hear it/feel it and the car wouldn't make the power it did without it. But I'd also been doing loads of testing on axle stands in the garage, does the high lift cam even work when the car is stationary? I Did some digging in the ECU software and came to the conclusion that I was not hitting "VTEC" when on axle stands... so all of my testing and trial/error was probably a perfectly normal "rattle" of when the small profile lobes get subjected to an RPM range they were never intended for.
The ECU checks for four things:
- 4900RPM or above
- 50% Throttle Position or above
- 50 kPA manifold pressure or above
- Minimum coolant temp (70deg I think).
On the axle stands, I can't reach the 50 kPa target because the supercharger bypass valve just dumps it all when not under load. The exact same thing occured on the speedo-pov video that I posted, I was cruising in neutral so no load = no boost = no VTEC, yo.
So why was the car still rattling on the road when VTEC was very much active? I watched some videos back that I took on collection day and noted that the rattle was inaudible when going up through the revs, you only heard it either for a split second during a gear shift, or when letting the revs decay naturally off-throttle. On both of those scenarios the TPS will be less than 50% and the manifold will go under vacuum.... hmmm.
A new theory was born, but it was late at night and the car was in bits... so excited/sleepless night followed by an early morning to put the car back together and I was ready to test!
I went out and warmed the car up, then gave it a "pull" from 2nd to 3rd gear. It rattled on the gearchange and I logged it as follows:
Sure enough you can see MAP and TPS dropping during the gear change, but also so does VTEC activation. Could this mean that the ECU is lobbing the "baby" cam into the mix at high RPM and that's the cause of the rattle?!
I pulled over and changed a couple of parameters, I left the TPS and MAP thresholds alone for activation but I changed them for deactivation, meaning that VTEC would stay active regardless of TPS and MAP once it had already been activated. Only dropping beneath 4900rpm would switch it off.
This time I did a 2nd/3rd/4th pull and you guessed it... no rattle, and logs support this by showing VTEC staying active:
I'm pretty bloody happy really, had a trackday booked for Sunday and was starting to prep one of the dailies for it! Obviously I need to clarify a few things with the tuners to make sure I've not cocked up something else, but I'd like to know why the car would be configured this way and whether it's normal for 2ZZ cars to be configured like it? Seems odd that you'd want the baby cam being thrown in at such high RPM where it's not intended.
Next in the firing line was the new manifold, plan was to get it off the car and inspect for cracks etc. Manifold came off as new (as expected) but the gasket/flange situation was a bit ropey:
Some signs there of blowing, the gasket supplied with the 2bular kit was aftermarket so I compared it with a Toyota one I had lying around. Bore holes are oversized on the perforated one so that probably wasn't helping it seal.
Needless to say I refitted with the Toyota one, but rattle persisted.
Next up I took the cam cover off again, it's normally a 10min job on a 2ZZ but my chargecooler being sat on top of it and full of water complicates the process slightly, but still I wanted another look.
Took lift bolts out this time to make sure they hadn't broken in the holes, also poked at the chain guides with a stick to see if they were loose... nope, everything checked out. I did get a bit excited with the camcover itself though as I noticed it rattled a bit, but that turned out to just be the PCV valve...
I was about ready to give up, I arranged with a local specialist (Performance Autocare shout-out) who agreed to shuffle some stuff around and have a poke around with me, and also provided loads of out of hours support via e-mail on this issue - great service!
I settled in for a night in the house (for a change) and then a friend messaged me to say that my video "sounds like high lift cam is not activating". That reminded me of a video I'd watched a few days earlier in which a 2ZZ converted MR2 had the exact same sound as me at the exact same RPM range and his issue turned out to be lack of high profile cam activation...
Hmmmm.
I've experienced this rattle on the road and at load when I knew for sure I was on high lift cam, as you can hear it/feel it and the car wouldn't make the power it did without it. But I'd also been doing loads of testing on axle stands in the garage, does the high lift cam even work when the car is stationary? I Did some digging in the ECU software and came to the conclusion that I was not hitting "VTEC" when on axle stands... so all of my testing and trial/error was probably a perfectly normal "rattle" of when the small profile lobes get subjected to an RPM range they were never intended for.
The ECU checks for four things:
- 4900RPM or above
- 50% Throttle Position or above
- 50 kPA manifold pressure or above
- Minimum coolant temp (70deg I think).
On the axle stands, I can't reach the 50 kPa target because the supercharger bypass valve just dumps it all when not under load. The exact same thing occured on the speedo-pov video that I posted, I was cruising in neutral so no load = no boost = no VTEC, yo.
So why was the car still rattling on the road when VTEC was very much active? I watched some videos back that I took on collection day and noted that the rattle was inaudible when going up through the revs, you only heard it either for a split second during a gear shift, or when letting the revs decay naturally off-throttle. On both of those scenarios the TPS will be less than 50% and the manifold will go under vacuum.... hmmm.
A new theory was born, but it was late at night and the car was in bits... so excited/sleepless night followed by an early morning to put the car back together and I was ready to test!
I went out and warmed the car up, then gave it a "pull" from 2nd to 3rd gear. It rattled on the gearchange and I logged it as follows:
Sure enough you can see MAP and TPS dropping during the gear change, but also so does VTEC activation. Could this mean that the ECU is lobbing the "baby" cam into the mix at high RPM and that's the cause of the rattle?!
I pulled over and changed a couple of parameters, I left the TPS and MAP thresholds alone for activation but I changed them for deactivation, meaning that VTEC would stay active regardless of TPS and MAP once it had already been activated. Only dropping beneath 4900rpm would switch it off.
This time I did a 2nd/3rd/4th pull and you guessed it... no rattle, and logs support this by showing VTEC staying active:
I'm pretty bloody happy really, had a trackday booked for Sunday and was starting to prep one of the dailies for it! Obviously I need to clarify a few things with the tuners to make sure I've not cocked up something else, but I'd like to know why the car would be configured this way and whether it's normal for 2ZZ cars to be configured like it? Seems odd that you'd want the baby cam being thrown in at such high RPM where it's not intended.
wevster said:
Well done for finding the issue!
Cheers! I'm still buzzing about it now but I really didn't enjoy the process, mainly as I was convinced something serious was wrong.kiethton said:
Great effort on the blower, until I read the post I was about to highlight the common Heater resistor module (my exige had the same(Ish) fault solved that way - AC which came and went (almost as if the pipe froze, culminating in no HVAC/airflow
Now that was a fun thing to troubleshoot, as I knew it was largely inconsequential! When you say heater resistor module do you mean for the fan-speed control? If so I swapped that out for the updated unit over winter, and really really really should have addressed the AC thermostat thing at the same time but it just wasn't on my radar as a known weakness. The thermostat prevents that exact symptom you describe of the evaporator freezing up and stopping the AC from working till' it thaws out again.TRACKDAY UPDATE!
After the "VTEC Clatter" debacle I was all ready to service my Civic (which hasn't moved since February) for the Blyton trackday I had booked on Sunday. After finally getting satisfaction that the car was healthy, I switched back to Plan A and got the Exige prepped... which consisted of a quick wash and setting the dampers up (7 clicks from hard all round, for the record).
I also noticed something which predates the new ECU, my IAT's seemed to be recording 10degrees higher all across the range. I checked back on some old ODB logs I took earlier in lockdown and sure enough on an 18degrees ambient day, the IAT's were 28degrees the moment I started the car. With the EMU I could now log this a little better, so took the IAT probe out with the log running and blew on it, sure enough the temp went up. I then sprayed it with contact cleaner, temp went down. When it dried/evaporated off - it settled back at ambient temperature... problem solved?
/Yawn, yes I know it's Blyton again but options have been really limited this year. I had "store credit" to spend from cancelled Angelesey (x2), Cadwell and Oulton and Blyton always seems to be on the dates I can make with availability. Still, it's good to benchmark myself and the car against a known quantity I guess.
The car didn't miss a beat all day, I did take the laptop and had fun checking on various logs between sessions. Proper geeky stuff really and I felt like a bit of a berk in the paddock, but secretly I was loving it
Some statistics:
Ambient: 16-18degrees C all day
IAT: Averaged in the mid 30's and peaked at low 40s towards the end of a session.
Gearbox temps: 80degrees when up to temp on the motorway cruising at NSL, peak track temp recorded all day was 103 degrees.
There was some really sexy kit in attendance, four(?) Atoms, some radical things and a BAC Mono! Trackday royalty!
As for my car, it felt quick - no real gremlins all day and it showed no signs of slowing during the sessions. Peak speeds certainly are up from previous sessions but overall laptime (based on video, not timing!!) is still down by a second or so on my best from Blyton. Reviewing video afterwards and it's just a couple of corners that I'm still not carrying as much entry speed into since I was on the OEM bilsteins. I know most people will swear that coilovers immediately drop 5seconds per lap, I'm more realistic/honest and frank about the fact I'm still chasing a setup that I'm comfortable with.
Don't get me wrong, I love the Nitrons and the variance in damping I can achieve - I just need to keep working on a setup that suits my style, my style being very much dependent on confidence rather than ultimate grip. In the right hands my car probably IS several seconds faster, I just don't have those hands
I'm also not saying that the car is a wayward deathtrap, the front end is just too strong for me - it'll turn into just about anything, and I tend to spend a lot of time waiting for/anticipating the rear coming round on me as a result, subconsciously this is causing me to turn in too early in a few places rather than just leaning on the car and 'chucking it like I used to do with my Elise. This is good news really, as I'm still fairly 'central' in my range of adjustability and if anything the S2 chassis will bias towards understeer - so it should be easy enough to dial out a bit of front end to give me some warning signs in future. My biggest failing is not adjusting during the course of the trackday, I just hammer on and try to drive through it.
I have a few ideas starting with more adjustment of my shocks during a day but I'm also coming round to the idea of a thicker ARB in the front to both protect my arch liners a bit more and to bring the bias of the car back to a bit of understeer - plus it's easy to remove/revert if it turns out to be a disaster.
The new power delivery is noticeable, there's a few areas at Blyton that previously I knew I could just mash the pedal at lower RPM and let the duller power curve carry me through a corner without upsetting the car too much, now I need to be more careful - through the faster Port Froid particularly I had to be a bit more delicate through the direction change, added a new challenge though and was fun to take on.
Only other niggle is that the brakes are still vibrating when they get warm. I've bedded in so many times now, but just can't get it right. It's not really slowing me down anymore as I just ignore it, but it's a bit annoying. They don't vibrate when going for full anchors-on mode, only when I partially use them from higher speed when trying to scrub a little bit off.
As Blyton is getting so samey, I had a play around with GoPro mounting positions and got some good footage from the rear number plate plinth. It captures a soundtrack of my car that I've never heard before as the cockpit is just dominated by SC whine which I find quite tedious tbh...!
https://www.youtube.com/watch?v=IiAakS8--SI
After the "VTEC Clatter" debacle I was all ready to service my Civic (which hasn't moved since February) for the Blyton trackday I had booked on Sunday. After finally getting satisfaction that the car was healthy, I switched back to Plan A and got the Exige prepped... which consisted of a quick wash and setting the dampers up (7 clicks from hard all round, for the record).
I also noticed something which predates the new ECU, my IAT's seemed to be recording 10degrees higher all across the range. I checked back on some old ODB logs I took earlier in lockdown and sure enough on an 18degrees ambient day, the IAT's were 28degrees the moment I started the car. With the EMU I could now log this a little better, so took the IAT probe out with the log running and blew on it, sure enough the temp went up. I then sprayed it with contact cleaner, temp went down. When it dried/evaporated off - it settled back at ambient temperature... problem solved?
/Yawn, yes I know it's Blyton again but options have been really limited this year. I had "store credit" to spend from cancelled Angelesey (x2), Cadwell and Oulton and Blyton always seems to be on the dates I can make with availability. Still, it's good to benchmark myself and the car against a known quantity I guess.
The car didn't miss a beat all day, I did take the laptop and had fun checking on various logs between sessions. Proper geeky stuff really and I felt like a bit of a berk in the paddock, but secretly I was loving it
Some statistics:
Ambient: 16-18degrees C all day
IAT: Averaged in the mid 30's and peaked at low 40s towards the end of a session.
Gearbox temps: 80degrees when up to temp on the motorway cruising at NSL, peak track temp recorded all day was 103 degrees.
There was some really sexy kit in attendance, four(?) Atoms, some radical things and a BAC Mono! Trackday royalty!
As for my car, it felt quick - no real gremlins all day and it showed no signs of slowing during the sessions. Peak speeds certainly are up from previous sessions but overall laptime (based on video, not timing!!) is still down by a second or so on my best from Blyton. Reviewing video afterwards and it's just a couple of corners that I'm still not carrying as much entry speed into since I was on the OEM bilsteins. I know most people will swear that coilovers immediately drop 5seconds per lap, I'm more realistic/honest and frank about the fact I'm still chasing a setup that I'm comfortable with.
Don't get me wrong, I love the Nitrons and the variance in damping I can achieve - I just need to keep working on a setup that suits my style, my style being very much dependent on confidence rather than ultimate grip. In the right hands my car probably IS several seconds faster, I just don't have those hands
I'm also not saying that the car is a wayward deathtrap, the front end is just too strong for me - it'll turn into just about anything, and I tend to spend a lot of time waiting for/anticipating the rear coming round on me as a result, subconsciously this is causing me to turn in too early in a few places rather than just leaning on the car and 'chucking it like I used to do with my Elise. This is good news really, as I'm still fairly 'central' in my range of adjustability and if anything the S2 chassis will bias towards understeer - so it should be easy enough to dial out a bit of front end to give me some warning signs in future. My biggest failing is not adjusting during the course of the trackday, I just hammer on and try to drive through it.
I have a few ideas starting with more adjustment of my shocks during a day but I'm also coming round to the idea of a thicker ARB in the front to both protect my arch liners a bit more and to bring the bias of the car back to a bit of understeer - plus it's easy to remove/revert if it turns out to be a disaster.
The new power delivery is noticeable, there's a few areas at Blyton that previously I knew I could just mash the pedal at lower RPM and let the duller power curve carry me through a corner without upsetting the car too much, now I need to be more careful - through the faster Port Froid particularly I had to be a bit more delicate through the direction change, added a new challenge though and was fun to take on.
Only other niggle is that the brakes are still vibrating when they get warm. I've bedded in so many times now, but just can't get it right. It's not really slowing me down anymore as I just ignore it, but it's a bit annoying. They don't vibrate when going for full anchors-on mode, only when I partially use them from higher speed when trying to scrub a little bit off.
As Blyton is getting so samey, I had a play around with GoPro mounting positions and got some good footage from the rear number plate plinth. It captures a soundtrack of my car that I've never heard before as the cockpit is just dominated by SC whine which I find quite tedious tbh...!
https://www.youtube.com/watch?v=IiAakS8--SI
Had an opportunity to take the car out yesterday for a rare non-trackday event. Performance Autocare in Knaresborough put on a meet for coffee and pork pies, so would be rude not to toddle over - especially as Jonny @ Performance Autocare had been so helpful in trying to isolate the "VTEC rattle" a couple of weeks ago.
Some nice Exige content in attendance across all generations, and good to catch up with a few characters too.
Also had a fiddle with traction control on the drive over. By RRR's own admission the RPM based strategy available with the OEM hardware is very limited - but since it's functionality that I've got, I at least one to know it's there and working if needed.
RRR had it setup in a very base sense, but it needs calibrating - quite difficult to do without having access to a wet skidpan or something but I could at least look to see if the base settings were working ok. What I found was that this is kicking in on dry roads (albeit cold tyres, so tiny amounts of slip) in a straight line doing 2nd/3rd/4th gear pulls - so it's clearly far too aggressive.
The way in which it kicks in is much more subtle than the OEM Lotus approach though, it seems Lotus cut spark as part of their TC strategy which leads to the 'pap pap pap' soundtrack as it engages. The EMU allows for this to be replicated, but also offers a fuel cut approach which seems to be the preferred option of higher end TC systems such as Racelogic etc for the longevity of the catalyst if nothing else.
So I clearly need to reduce the sensitivity of it so it's only stepping in for 'proper' slip events, despite the ABS S2 cars having wheel speed sensors at all four corners - the ECU/loom only receives speed data from one (NSR) so I can't use axle speed differential for detecting slip (ECUMaster do have an addon for this though if proper TC is desired) so instead I need to use 'RPM Gain' for detection, which is pretty basic really.
The metric tracked by the ECU is "dRPM" (delta RPM = current change in RPM, if it spikes up in such a way that the current speed/gearing should not allow - then this is interpreted as slip). On an open diff car this is particularly useless as you'll almost always get a spike in RPM during accelerated corners due to the inside rear spinning up. For that reason I won't invest too much time into this, as realistically TC is never going to be used on track - but maybe if I one day end up with a diff on a wet trackday, it would be good to know roughly how this stuff works.
The ECU also has the capacity to take up to 10 positions from a rotary switch which applies a multiplier to the dRPM figure to either increase or decrease sensitivity. That same sensitivity adjustment can be made via a laptop so I could still probably experiment with it a bit. I think for now I'll manually change the sensitivity until I find a point in which a dry pull through the gears is not causing TC intervention, then I know I at least have a half decent baseline that might save me if I have a brainfart on a wet road.
Some nice Exige content in attendance across all generations, and good to catch up with a few characters too.
Also had a fiddle with traction control on the drive over. By RRR's own admission the RPM based strategy available with the OEM hardware is very limited - but since it's functionality that I've got, I at least one to know it's there and working if needed.
RRR had it setup in a very base sense, but it needs calibrating - quite difficult to do without having access to a wet skidpan or something but I could at least look to see if the base settings were working ok. What I found was that this is kicking in on dry roads (albeit cold tyres, so tiny amounts of slip) in a straight line doing 2nd/3rd/4th gear pulls - so it's clearly far too aggressive.
The way in which it kicks in is much more subtle than the OEM Lotus approach though, it seems Lotus cut spark as part of their TC strategy which leads to the 'pap pap pap' soundtrack as it engages. The EMU allows for this to be replicated, but also offers a fuel cut approach which seems to be the preferred option of higher end TC systems such as Racelogic etc for the longevity of the catalyst if nothing else.
So I clearly need to reduce the sensitivity of it so it's only stepping in for 'proper' slip events, despite the ABS S2 cars having wheel speed sensors at all four corners - the ECU/loom only receives speed data from one (NSR) so I can't use axle speed differential for detecting slip (ECUMaster do have an addon for this though if proper TC is desired) so instead I need to use 'RPM Gain' for detection, which is pretty basic really.
The metric tracked by the ECU is "dRPM" (delta RPM = current change in RPM, if it spikes up in such a way that the current speed/gearing should not allow - then this is interpreted as slip). On an open diff car this is particularly useless as you'll almost always get a spike in RPM during accelerated corners due to the inside rear spinning up. For that reason I won't invest too much time into this, as realistically TC is never going to be used on track - but maybe if I one day end up with a diff on a wet trackday, it would be good to know roughly how this stuff works.
The ECU also has the capacity to take up to 10 positions from a rotary switch which applies a multiplier to the dRPM figure to either increase or decrease sensitivity. That same sensitivity adjustment can be made via a laptop so I could still probably experiment with it a bit. I think for now I'll manually change the sensitivity until I find a point in which a dry pull through the gears is not causing TC intervention, then I know I at least have a half decent baseline that might save me if I have a brainfart on a wet road.
Quiet week on the spanners, just used the car for some menial tasks like collecting croissants on Sunday morning...
and a nice evening clean.
...but I couldn't keep the car in one piece for too long could I?!
I posted about an issue a while back (before the new ECU) in which the car would occasionally stall when cruising up to a stop in neutral or with the clutch in, revs would just drop too far below idle target and the car would shudder and die. The new ECU 'fixed' this in a sense, in that the revs still fall but the ECU jumps in and throws a load of timing/fuelling correction at it to prevent the stall and re-establish the idle but it still feels a bit jarring to be honest so I wanted to hunt down the root cause.
I've spent some time remotely with RRR and I've expanded my learning a bit to make some incremental changes to the idle correction mechanisms to try and smooth it out (it feels a bit like a tank slapper at the moment, idle drops too low - ECU overcorrects, then it goes too high, ECU overcorrects, etc until it eventually settles down). We're making progress on it but I don't think I'll be completely happy with it until the issue is sorted properly.
As the car is DBW, there's not much at first glance that could be physically wrong. My Elise let me down once by the potentiometer in the throttle pedal failing, and the ECU trapped me in limp home mode for the duration of a 3 day trip around the Lakes
, the research I did at that time suggested that the GM parts used for that potentiometer are known for going bad - so perhaps I'm seeing early signs of that... but as the issue is exclusively at idle, I'm thinking not.
As for the TB itself, there is of course another potentiometer with a motor and some gears - really simple stuff but I decided to take it off anyway for a look.
Other than sloshing a bit of coolant around, it's not too difficult or awkward to remove even with the chargecooler plumbing in place. Removing CC and catch cans would have made access much easier though.
Once off the mechanism could be exposed and I've found a potential path to investigate.
There's a small "stop screw" which the mechanism comes to a rest at. The butterfly is spring loaded so will always try to default to full close but that screw prevents it from shutting 100% (as otherwise the car would stall at idle all the time).
However if I tweak the flap a bit with my hand, there's some slack in the mechanism that means it's closing slightly further than the motors "rest" position. I video'd it here to try and capture it better:
https://www.youtube.com/watch?v=-WfsIj3VppY&fe...
It's very close, but perhaps winding that screw in half a turn would take that slack out and give the butterfly a slightly more "open" closed position.
Once I understood a bit more about how the mechanism worked, I did a bit more googling and found a thread here which describes exactly this: https://www.lotustalk.com/threads/solved-my-exige-... so it's certainly worth a try.
The coolant lines will make constantly removing/refitting annoying so I'll probably loop those for now. I know a lot of the Celica guys bypass the TB coolant anyway in a vain attempt to lower intake temps so the car won't blow up without it.
I also discovered a small support bracket for the TB was broken (before I touched it, honest!!). Not a big deal, I doubt it's particularly load bearing but it's always a possible source of rattle so I'll get that replaced once I can find a non-Lotus premium part number to stick into eBay...
No conclusion to this yet, will do a bit more homework before I adjust anything and will report back with results (or lack thereof).
and a nice evening clean.
...but I couldn't keep the car in one piece for too long could I?!
I posted about an issue a while back (before the new ECU) in which the car would occasionally stall when cruising up to a stop in neutral or with the clutch in, revs would just drop too far below idle target and the car would shudder and die. The new ECU 'fixed' this in a sense, in that the revs still fall but the ECU jumps in and throws a load of timing/fuelling correction at it to prevent the stall and re-establish the idle but it still feels a bit jarring to be honest so I wanted to hunt down the root cause.
I've spent some time remotely with RRR and I've expanded my learning a bit to make some incremental changes to the idle correction mechanisms to try and smooth it out (it feels a bit like a tank slapper at the moment, idle drops too low - ECU overcorrects, then it goes too high, ECU overcorrects, etc until it eventually settles down). We're making progress on it but I don't think I'll be completely happy with it until the issue is sorted properly.
As the car is DBW, there's not much at first glance that could be physically wrong. My Elise let me down once by the potentiometer in the throttle pedal failing, and the ECU trapped me in limp home mode for the duration of a 3 day trip around the Lakes
, the research I did at that time suggested that the GM parts used for that potentiometer are known for going bad - so perhaps I'm seeing early signs of that... but as the issue is exclusively at idle, I'm thinking not.As for the TB itself, there is of course another potentiometer with a motor and some gears - really simple stuff but I decided to take it off anyway for a look.
Other than sloshing a bit of coolant around, it's not too difficult or awkward to remove even with the chargecooler plumbing in place. Removing CC and catch cans would have made access much easier though.
Once off the mechanism could be exposed and I've found a potential path to investigate.
There's a small "stop screw" which the mechanism comes to a rest at. The butterfly is spring loaded so will always try to default to full close but that screw prevents it from shutting 100% (as otherwise the car would stall at idle all the time).
However if I tweak the flap a bit with my hand, there's some slack in the mechanism that means it's closing slightly further than the motors "rest" position. I video'd it here to try and capture it better:
https://www.youtube.com/watch?v=-WfsIj3VppY&fe...
It's very close, but perhaps winding that screw in half a turn would take that slack out and give the butterfly a slightly more "open" closed position.
Once I understood a bit more about how the mechanism worked, I did a bit more googling and found a thread here which describes exactly this: https://www.lotustalk.com/threads/solved-my-exige-... so it's certainly worth a try.
The coolant lines will make constantly removing/refitting annoying so I'll probably loop those for now. I know a lot of the Celica guys bypass the TB coolant anyway in a vain attempt to lower intake temps so the car won't blow up without it.
I also discovered a small support bracket for the TB was broken (before I touched it, honest!!). Not a big deal, I doubt it's particularly load bearing but it's always a possible source of rattle so I'll get that replaced once I can find a non-Lotus premium part number to stick into eBay...
No conclusion to this yet, will do a bit more homework before I adjust anything and will report back with results (or lack thereof).
Fonzey said:
No conclusion to this yet, will do a bit more homework before I adjust anything and will report back with results (or lack thereof).
The conclusion to that, is it sort of fixed it. The idle did indeed rise as a result of the tweak and the stalling issues vanished. I checked the ECU logs and could see it desperately trying to retard things to bring the idle back down, so I instead set the target idle from 850 to 950 and the car feels much happier. Asking around since, and it seems loads of people with aftermarket ECUs on the 2zz Lotus ended up raising their idle for this reason.With Covid restrictions ramping up again my next trackday of Anglesey at the end of October was feeling threatened so I wanted to try and get out in September. Everything has been fully booked all summer so I put a shout out onto a FB group which is intended for the buying/selling of track time and I got an offer of Croft on tuesday this week. I snapped his hand off, and after not hearing much over the weekend we finally got it confirmed with the TDO on Monday.
The car didn't need much prep, just lobbed my tools in the back and packed my helmet then I was off! With not much time to think ahead, for the first time ever I didn't have weather anxiety on the run up to a trackday as the forecast was bob on. Nice early start as the sun was just starting to cut through the mist.
Not many Lotus in attendance but I quite like the colour of my paddock-mate.
(Supercharged K-Series btw, fairly rare configuration nowadays but seemed to go well!)
As this was technically a "bonus" trackday I had decided I'd use it as a day to experiment with suspension setup, something I'm usually reluctant to change mid-trackday because I don't want to lose track time to a naff setup or get myself lost in iterations. I normally stick quite close to the 'middle' of the Nitron settings, hovering around the central settings and just tweaking in small increments in an attempt to alter the balance of the car a bit but today I decided I was going to run much stiffer and see if I could find the point where things got *too* stiff.
My starting settings (taken from my last Croft day) was 8/8 from hard (total of 20 clicks available) and I did the first couple of sessions like this. Car felt good, but maybe felt too soft at the rear as the car was pushing on a little bit and I think I was lifting the occasional front wheel.... in fact, I know I was
Through buying a cancellation I'd also inherited a tuition session in the mid morning which was a great use of 20mins. I've never felt like I had 'Tower' anywhere near decent and so we focussed on that and got it a bit better, but I know where to keep improving there for next time. Other feedback was generally strong, just said there's loads of time on the table through commitment in the 'Esses which I'm well aware of, but comfortable with my commitment levels through there for now...!
I popped out at lunch for fuel and food and bumped into a fellow petrolhead (not linked to the trackday) in a Clio 182 trophy - don't see those too often so had a good chat about all things cars before hurrying back to the circuit.
After lunch I'd brought the settings to 5F 2R (from hard) and I remained like this for the rest of the day. Traction felt really good like this, particularly on the hairpin - I still can't be too heavy footed through there but it was loads better than earlier in summer. The only hint I got that things were too stiff in the rear was that I'd occasionally feel the rear hopping a bit when entering the hairpin too quickly, quickly followed my a small slide on entry, I found slowing things down on entry and being more aggressive on exit was an acceptable response to this.
In hindsight I think I'd have like to take the fronts a bit stiffer. I didn't realise on the day that my F and R adjustments were a few clicks apart as I'd been making small incremental changes through the day. If I realised it was 5/2 I'd have tried at least one session with 4/2 to see how things changed.
My last two sessions were both brilliant, but I could feel the brakes starting to struggle a bit. I initially thought it was just the fluid getting too hot because the pedal was just going a bit long. I got a bit of footage from the penultimate session:
https://www.youtube.com/watch?v=OytIxLI31wo&ab...
On the final session I pretty much had the track to myself along with a race prepped MR2. I was obviously a fair bit quicker on the straights but it was clear this guy had a few things to teach me about commitment through the faster bends so we settled in for a few laps, I would give him space on the straights and then we'd follow through the rest of the lap quite closely. We then swapped places and did similar until his tyres faded and my brakes felt like they'd had enough. Unfortunately the GoPro batteries died quite early into this session so didn't capture any of the good parts, but despite being "not the fastest" laps it was great fun following through and pushing each other on a bit.
As the car cooled down on the way home the brakes started making all sorts of weird and wonderful noises - analysis the following day suggests I got about as much as I could have done out of the RS14s...
These have lasted 5 months and 5 trackdays, I don't think that's TOO bad but I'd like to try a different pad next to see if I can find something a little harder wearing. Even if it punishes my discs a bit, as currently they look unharmed in 2 years and 10-12 trackdays.
I've raided my box of 'get me home pads' to keep me going for now (stuck in the EBC red stuff I got with the car and OEM Brembo rears...) while I canvas some opinion and take a punt on the next brand.
On the ECU front, nothing really to report - car pulled hard and fast all day. I monitored gearbox temps again and it feels like the temps are "settled" at 80degrees C, that seems to be the status quo with regular road driving, then once on track it seems to gain approx. 2 degrees per minute and my sessions usually average 10mins of 'hot lapping' which is consistently seeing me peak at 100deg. On the later sessions I had a longer one, and this pattern continued up to 112-113 degrees so it's reasonable to think that a 20-25min session (way beyond my physical capabilities...) would see temps spiking to dangerous levels.
IATs didn't go higher than low 40s.
I suspected my aux belt tensioner pulley may be struggling a bit. In hindsight it was probably my imagination but the soundtrack of my car at idle had subtly changed after Croft, it seemed to be coming from the belts and the tensioner had some signs of weapage.
I can only assume it's time served 'beyond optimal range' contributed due to the alternator not being bolted up right, and my belt requiring extra tension for all those years/miles but maybe it's just one of those things. In any case, I had two options:
1- Replace the whole unit (damper, arm and pulley)- pricing starting at ~ £120 for SKF or many times that for Lotus/Toyota, would also mean undoing engine mounts and lifting the engine for clearance.
2- Replace just the damper, not available through Lotus/Toyota but SKF do one for £40.
Obviously went SKF, mainly due to the easier swap rather than the cost.
Whilst the aux belt was off, I ran the car for a few seconds and I think the noise was still present... I say think, because I'm now starting to believe I was being overly attentive to something that probably has always been there...
Anyway, the old one was definitely 'passed it' because when I compressed it on the bench with a g-clamp, gunk came out of it.
With that done, onto my brakes. I posted the photo of my Pagid RS14 remains after Croft and I thought I'd give all four calipers a good clean out ready to accept the replacements when they come. I had to pop a double take when I saw the OSF disc....
This could actually be good news. I've never been THAT happy with the brakes since fitting RS14s, their ultimate performance was brilliant, far better than the RS42s but on partial pressure they had horrible vibrations, that no amount of bedding in (or trackdays) seemed to resolve. In hindsight that was almost certainly down to the disc itself, before it cracked I imagine it was probably not running true on its way to failure. It also explains the heavier pad consumption on the OSF corner, the others are still 'almost dead' but I could have maybe got one more trackday out of them had the wear been even.
So hopefully now with fresh discs and pads, I'll be well on my way.
As for the replacements, SeriouslyLotus to the rescue - no attempt at all to blame the failure on me/track abuse/poor maintenance/etc - just a straight up "that's not right" and replacements were with me 18 hours later. Failures happen, but it would be so easy for a vendor to hide behind the "not covered for track use" b
ks that certain other vendors do around the Lotus market...
Obviously the replacements are different, they're just belled versions of the same blanks which were in stock and the single piece ones were not.
Now, just pads to decide on...
I can only assume it's time served 'beyond optimal range' contributed due to the alternator not being bolted up right, and my belt requiring extra tension for all those years/miles but maybe it's just one of those things. In any case, I had two options:
1- Replace the whole unit (damper, arm and pulley)- pricing starting at ~ £120 for SKF or many times that for Lotus/Toyota, would also mean undoing engine mounts and lifting the engine for clearance.
2- Replace just the damper, not available through Lotus/Toyota but SKF do one for £40.
Obviously went SKF, mainly due to the easier swap rather than the cost.
Whilst the aux belt was off, I ran the car for a few seconds and I think the noise was still present... I say think, because I'm now starting to believe I was being overly attentive to something that probably has always been there...
Anyway, the old one was definitely 'passed it' because when I compressed it on the bench with a g-clamp, gunk came out of it.
With that done, onto my brakes. I posted the photo of my Pagid RS14 remains after Croft and I thought I'd give all four calipers a good clean out ready to accept the replacements when they come. I had to pop a double take when I saw the OSF disc....
This could actually be good news. I've never been THAT happy with the brakes since fitting RS14s, their ultimate performance was brilliant, far better than the RS42s but on partial pressure they had horrible vibrations, that no amount of bedding in (or trackdays) seemed to resolve. In hindsight that was almost certainly down to the disc itself, before it cracked I imagine it was probably not running true on its way to failure. It also explains the heavier pad consumption on the OSF corner, the others are still 'almost dead' but I could have maybe got one more trackday out of them had the wear been even.So hopefully now with fresh discs and pads, I'll be well on my way.
As for the replacements, SeriouslyLotus to the rescue - no attempt at all to blame the failure on me/track abuse/poor maintenance/etc - just a straight up "that's not right" and replacements were with me 18 hours later. Failures happen, but it would be so easy for a vendor to hide behind the "not covered for track use" b
ks that certain other vendors do around the Lotus market...Obviously the replacements are different, they're just belled versions of the same blanks which were in stock and the single piece ones were not.
Now, just pads to decide on...
It was pretty much a three way tie for brake pads between the following:
- Carbone Lorriane RC6
- Performance Friction 08
- Carbotech XP8
All get similar reviews of perhaps being a hair ahead of the Pagid RS14 for ultimate performance, but realistically there's probably nowt' in it.
After the disc crack discovery I should probably be fair to RS14 and give them another chance, but the only way to really form an opinion is to try a bit of everything... so that's what I'll do, starting with the Carbotechs:
They're shiny, so points for that straight away. I went for the XP8's first because although I received the least feedback on these, it was universally good. With the CL's and the PF's it was a case of "they're excellent BUT XXX" but really heard no complaints from the Carbotechs. They're made to order direct from Carbotech Europe, but even then the turnaround was only a few days.
New discs and pads in:
Gave the fluid a good flushing out too and replaced with RBF660. I've been a religious user of ATE200 (previously the blue stuff) for years but struggled to get it this time.
The XP8's came with some quite specific bedding in instructions, no ambiguity here.
I went for the procedure at 7am Sunday morning, roads a bit damp but it would do. After the first 4 braking events I started getting good vibes from them, really good bite in the first ~20% of pedal travel and then a nice solid feeling under foot until the ABS eagerly kicked in on the damp roads. Once I completed the prescribed 70-10 slows I settled in for a 15min 'moderately hard drive' and used the brakes a bit more normally and found them fantastic at intermediate pressure. I probably struggled to get them hot enough for bedding purposes, so I'll probably repeat this process when I next go out in the dry - but really impressed so far.
Not a hint of squeal so far and the dust doesn't seem out of the ordinary. So far so good.
- Carbone Lorriane RC6
- Performance Friction 08
- Carbotech XP8
All get similar reviews of perhaps being a hair ahead of the Pagid RS14 for ultimate performance, but realistically there's probably nowt' in it.
After the disc crack discovery I should probably be fair to RS14 and give them another chance, but the only way to really form an opinion is to try a bit of everything... so that's what I'll do, starting with the Carbotechs:
They're shiny, so points for that straight away. I went for the XP8's first because although I received the least feedback on these, it was universally good. With the CL's and the PF's it was a case of "they're excellent BUT XXX" but really heard no complaints from the Carbotechs. They're made to order direct from Carbotech Europe, but even then the turnaround was only a few days.
New discs and pads in:
Gave the fluid a good flushing out too and replaced with RBF660. I've been a religious user of ATE200 (previously the blue stuff) for years but struggled to get it this time.
The XP8's came with some quite specific bedding in instructions, no ambiguity here.
I went for the procedure at 7am Sunday morning, roads a bit damp but it would do. After the first 4 braking events I started getting good vibes from them, really good bite in the first ~20% of pedal travel and then a nice solid feeling under foot until the ABS eagerly kicked in on the damp roads. Once I completed the prescribed 70-10 slows I settled in for a 15min 'moderately hard drive' and used the brakes a bit more normally and found them fantastic at intermediate pressure. I probably struggled to get them hot enough for bedding purposes, so I'll probably repeat this process when I next go out in the dry - but really impressed so far.
Not a hint of squeal so far and the dust doesn't seem out of the ordinary. So far so good.
Simon182 said:
I hope that hasn't replaced the penis-giraffe clock!
Never, that's a family heirloom!RazerSauber said:
Superb thread. Good to see the disk manufacturer putting their money where their mouth is too, top marks for that.
Glad you're enjoying it, yes no issues whatsoever - couldn't have asked for a better response really.Remember this?
Bracket thing from my throttlebody, as far as I can gather it had been broken for a long time - at least as long as I've owned the car so I took it off when adjusting my idle position a few weeks ago with the intention of sourcing a new one or getting it fixed. Sourcing a new one was a total dead end, as I can't find it on any parts diagrams or part number lists - so it must be included with the TB assembly itself rather than being a distinct part.
So thanks to a favour from a friend of a friend, I got it welded up instead.
Quick blast with my grinder to clean it up a bit..
...and a lick of paint, et Voila.
It's still not exactly clear what purpose this serves... it's been broken for god knows how long, and I ran Croft without it fitted at all but it's back on now so I suppose I can sleep again at night.
Oh, I also reverted the tweak I made to the TB stopper position just because it was made redundant by the fact I can change the idle target in the ECU directly.
Bracket thing from my throttlebody, as far as I can gather it had been broken for a long time - at least as long as I've owned the car so I took it off when adjusting my idle position a few weeks ago with the intention of sourcing a new one or getting it fixed. Sourcing a new one was a total dead end, as I can't find it on any parts diagrams or part number lists - so it must be included with the TB assembly itself rather than being a distinct part.
So thanks to a favour from a friend of a friend, I got it welded up instead.
Quick blast with my grinder to clean it up a bit..
...and a lick of paint, et Voila.
It's still not exactly clear what purpose this serves... it's been broken for god knows how long, and I ran Croft without it fitted at all but it's back on now so I suppose I can sleep again at night.
Oh, I also reverted the tweak I made to the TB stopper position just because it was made redundant by the fact I can change the idle target in the ECU directly.
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