Phoenix from the flames - Porsche Boxster with an Audi 2.7T
Discussion
I've not spent much time on this lately, I've been busy doing house stuff which I hate. The car is mainly running well, no real issues but lots of little things that need finishing. They aren't urgent so they aren't getting done. I still haven't got to the bottom of my ABS/PSM error warning lights. They are on the canbus, I'm 95% sure I know the right addresses for them and I've got the right data but I can't get them to switch off, not sure if I'm doing some wrong. It could simply have a fault code on the ABS that needs clearing and be nothing to do with the canbus. I have a scanner that reads the PSM but not the ABS, might need to invest in something decent. It's a minor annoyance but not an issue until MOT time in January.
I've got a problem with the power steering, it's not doing that much if you steer with the engine at idle speed but is ok if you raise the revs. This makes for inconsistency when parking. It also whines quite loudly when steering, I can hear it through my det-cans when going around a roundabout. I am under driving the pump using the smaller pulley from a Boxster, I did buy a larger Audi pulley but the drive belt is slightly too short to fit. Changing the drive belt is a big job as my engine mount bracket bolts up in the middle of it, to get the bracket off I'll probably need to remove a coolant hose and drain the system. Not sure I can be bothered at the moment, think it probably wants a new pump anyway.
One issue that did crop up was there became a harness through the car, vibrations and rattles, on inspection, my gearbox had dropped and was rubbing the cross member. I removed the brackets holding the gearbox and the mounts and couldn't see any issues. Only thing I could think was the mounts had dropped as they'd bedded in and gone through a few heat cycles. They are 964 RS aftermarket copies. Have to be honest I wasn't liking them, there was a harshness through the car with them at certain RPM's. I had to space them up with washers as a temporary thing.
I'd bought them from type911shop.co.uk, I sent them an email querying it, they said they've sold hundreds and had 3 complaints about this issue, I guess maybe I got some bad ones or more likely, a small drop is a non issue on most cars but on mine the clearances are tighter. I can recommend them, their customer service is good, I asked if I could return them for some DesignTek mounts, they sent me some next day and waived the delivery. Just need to return mine now for the refund.
I'm dubious about some aftermarket parts, these mounts are £300 which I think has a healthy amount of Porsche tax added into the price. I have to say, they've been a complete revelation, the harshness is all gone, I can feel an improvement generally with how taught the back end feels and have noticed a nicer gear change also. Compared to the 964RS mounts it's now somehow tighter and more refined, how is that possible? Definitely worth the money.
The tuning is going well, I'm up to 2200mbar which is around 17psi, car is pulling strong. Still ironing out a couple of quirks like a boost spike when changing gear, I think the boost solenoid PID needs a bit more work. I've started using 4th gear for runs and I'm wondering if I'm best off getting it back on the dyno, I'm confident I can do all the tuning myself from this point and I want to, but it's doing 130mph at the redline in 4th. It's quite fast to be going when my concentration is spread around, I have one eye on a wideband and det-cans on. It's hard to read those Mexican road signs also
I've got a problem with the power steering, it's not doing that much if you steer with the engine at idle speed but is ok if you raise the revs. This makes for inconsistency when parking. It also whines quite loudly when steering, I can hear it through my det-cans when going around a roundabout. I am under driving the pump using the smaller pulley from a Boxster, I did buy a larger Audi pulley but the drive belt is slightly too short to fit. Changing the drive belt is a big job as my engine mount bracket bolts up in the middle of it, to get the bracket off I'll probably need to remove a coolant hose and drain the system. Not sure I can be bothered at the moment, think it probably wants a new pump anyway.
One issue that did crop up was there became a harness through the car, vibrations and rattles, on inspection, my gearbox had dropped and was rubbing the cross member. I removed the brackets holding the gearbox and the mounts and couldn't see any issues. Only thing I could think was the mounts had dropped as they'd bedded in and gone through a few heat cycles. They are 964 RS aftermarket copies. Have to be honest I wasn't liking them, there was a harshness through the car with them at certain RPM's. I had to space them up with washers as a temporary thing.
I'd bought them from type911shop.co.uk, I sent them an email querying it, they said they've sold hundreds and had 3 complaints about this issue, I guess maybe I got some bad ones or more likely, a small drop is a non issue on most cars but on mine the clearances are tighter. I can recommend them, their customer service is good, I asked if I could return them for some DesignTek mounts, they sent me some next day and waived the delivery. Just need to return mine now for the refund.
I'm dubious about some aftermarket parts, these mounts are £300 which I think has a healthy amount of Porsche tax added into the price. I have to say, they've been a complete revelation, the harshness is all gone, I can feel an improvement generally with how taught the back end feels and have noticed a nicer gear change also. Compared to the 964RS mounts it's now somehow tighter and more refined, how is that possible? Definitely worth the money.
The tuning is going well, I'm up to 2200mbar which is around 17psi, car is pulling strong. Still ironing out a couple of quirks like a boost spike when changing gear, I think the boost solenoid PID needs a bit more work. I've started using 4th gear for runs and I'm wondering if I'm best off getting it back on the dyno, I'm confident I can do all the tuning myself from this point and I want to, but it's doing 130mph at the redline in 4th. It's quite fast to be going when my concentration is spread around, I have one eye on a wideband and det-cans on. It's hard to read those Mexican road signs also
Escy said:
I've not spent much time on this lately, I've been busy doing house stuff which I hate. The car is mainly running well, no real issues but lots of little things that need finishing. They aren't urgent so they aren't getting done. I still haven't got to the bottom of my ABS/PSM error warning lights. They are on the canbus, I'm 95% sure I know the right addresses for them and I've got the right data but I can't get them to switch off, not sure if I'm doing some wrong. It could simply have a fault code on the ABS that needs clearing and be nothing to do with the canbus. I have a scanner that reads the PSM but not the ABS, might need to invest in something decent. It's a minor annoyance but not an issue until MOT time in January.
When I was having a play with the RX-8 clocks you had to keep repeatedly sending the same message to clear the warning lights. Multiple times a second. I wouldn't be particularly surprised if the Porsche uses a related Bosch HU/CM which will do a similar thing. Can't speak for the intracacies of the Porsche but I believe it uses the Bosch system. Again when looking at the RX-8, the DSC (PSM in Porsche speak) and ABS are the same module, the Bosch HU/CM (Hydraulic Unit/Control Module) and it *needs* to talk to the PCM. If it can't then you get an ABS & DSC warning. It uses the serial of the PCM so that if you replace either you get warnings.
To change the serial used you need a device that uses the K-line for communications and it is also password protected.
To get round it in the case of the RX-8 there was an ABS only unit that made things easier or you can fake the comms with the PCM if you have the original to clone what signal it gives on the K-line (which is also where the DSC (or PSM) can request more or less torque.
It's probably worth reading what it *thinks* the errors are, IIRC the HU/CM would give stored errors over CAN (ie accessible via any old ELM327) and it may be a genuine issue.
To change the serial used you need a device that uses the K-line for communications and it is also password protected.
To get round it in the case of the RX-8 there was an ABS only unit that made things easier or you can fake the comms with the PCM if you have the original to clone what signal it gives on the K-line (which is also where the DSC (or PSM) can request more or less torque.
It's probably worth reading what it *thinks* the errors are, IIRC the HU/CM would give stored errors over CAN (ie accessible via any old ELM327) and it may be a genuine issue.
The ABS and PSM are also one unit on the Porsche. I think maybe when my diagnostic scanner can read the PSM, that might actually be the ABS unit also. I need to pull my finger out with it, have the MOT in the next few months.
I've been in 2 minds about going back to the dyno or tuning it myself. It's been raining hard all week, I took it out one evening when it was light rain which quickly turned torrential, I got nothing done, decided I'm best off getting it to the dyno, get it all over and done in a day (hopefully!). I rang Indigo GT where I had gone before, they could get me in pretty quick, Monday the 9th.
The car must of heard me make the phone call, went under it and there was oil on the sump. I had a dodgy bolt, had snapped one previously when changing the sump, I'd decided to drill it out with the sump in place as I didn't fancy swarf going all over the place with the sump off. That was a poor decision as I'd drilled it out on the piss. Had tapped it but the thread was compromised. It had been fine for a while but had finally decided it was going to leak. I removed the sump and fitted a helicoil.
While I was under it doing the sump I noticed my charge cooler lines had started to kink where they enter the engine bay. I cut those sections out replaced them with 90 degree rubber hoses. To bleed the system I have to remove the front bumper.
I've added a low coolant sensor to my water/meth tank.
Since the engine mount had to come off to sort out the charge cooler lines I thought i'd take the opportunity to replace the power steering pump. Old one out, the replacement should come in the next few days.
I've been in 2 minds about going back to the dyno or tuning it myself. It's been raining hard all week, I took it out one evening when it was light rain which quickly turned torrential, I got nothing done, decided I'm best off getting it to the dyno, get it all over and done in a day (hopefully!). I rang Indigo GT where I had gone before, they could get me in pretty quick, Monday the 9th.
The car must of heard me make the phone call, went under it and there was oil on the sump. I had a dodgy bolt, had snapped one previously when changing the sump, I'd decided to drill it out with the sump in place as I didn't fancy swarf going all over the place with the sump off. That was a poor decision as I'd drilled it out on the piss. Had tapped it but the thread was compromised. It had been fine for a while but had finally decided it was going to leak. I removed the sump and fitted a helicoil.
While I was under it doing the sump I noticed my charge cooler lines had started to kink where they enter the engine bay. I cut those sections out replaced them with 90 degree rubber hoses. To bleed the system I have to remove the front bumper.
I've added a low coolant sensor to my water/meth tank.
Since the engine mount had to come off to sort out the charge cooler lines I thought i'd take the opportunity to replace the power steering pump. Old one out, the replacement should come in the next few days.
I've got a hose with a spring in for my air filters.
I like that clear hose I'm using because I can see any air pockets in it plus it's thinner and lighter than rubber hose, the downsides are it's hard to seal with clamps/jubilee clips and I don't think it's much good with heat, softens up and folds in on itself where its curved. It then cools down in that shape and is rock hard again. I've not got all rubber hose in the engine compartment.
I like that clear hose I'm using because I can see any air pockets in it plus it's thinner and lighter than rubber hose, the downsides are it's hard to seal with clamps/jubilee clips and I don't think it's much good with heat, softens up and folds in on itself where its curved. It then cools down in that shape and is rock hard again. I've not got all rubber hose in the engine compartment.
Today was the big day. Dyno time. The last time was a bit of a s
t show so I wasn't overly confident. First run, at wastegate pressure made 300bhp, not a bad start. Second run which is where I'd got it to on the street made 370bhp at 1.2 bar. I'm starting to feel confident, Anthony the tuner starts sorting out the boost control, ignition and fuelling. It's then at around 380bhp, we start upping the boost but it's not responding how I'd expected, getting small bhp gains for the extra boost rather than large jumps, it got to the point where adding 0.2bar made no difference at all. I was hoping for 450bhp without meth. I've ended up with 404bhp. I couldn't get the meth working, a pipe kept popping off. I also had a boost pipe come off twice but other than that the day was problem free.
There is obviously a restriction somewhere. Not sure what, the turbos are Chinese specials but they were making the boost and holding the boost to the redline so I think they weren't the issue. The egt's were good so don't think there was a problem with the exhaust size. The charge coolers might be restrictive but they came off a 600bhp Mercedes so I'd assume not.
I'm thinking it might be a combination of the boost pipes being slightly small and the route from the turbos to the inlet manifold having a few 90 degree bends. The exhaust also has a few 90 degree bends in it.
Here is the dyno graph, 404bhp, 470ft/lbs. I was told that other cars often make 20+bhp on a different dyno. Anthony spent a lot of time on the boost control and power delivery. I thought it best to get it coming in progressive rather than a huge slug of torque as I'm rear wheel drive. I've only driven it home, it drives much nicer at low RPM now, the extra ignition timing has made a big difference. It was busy and wet so only pinned it once. I'll be honest, I'm a bit underwhelmed. It feels fast but I think the car hides the speed quite well, combination of being heavier and more refined than previous fast cars I've owned. I'd been driving it around at 370bhp thinking it felt like 300bhp so I guess the extra 30bhp was never going to set my world alight. It's fast and I'm happy, need to drive it properly to form an opinion. In retrospect I think I prefer my power delivery a bit more savage, my friends S4 that's a similar spec feels like a kick in the bks when it comes on boost.
This is the meth pipe that failed, the T-piece wouldn't hold the pipe. It's been fine before, typical! Good job it's a 50/50 meth/water mix, methanol would have caught fire squirting all over the exhaust manifolds.
I got home and found I've got an oil leak again. Yay!
The plan going forward is to get the methanol injection going and add some timing back in. My knock control is all set up now so it'll be something I can do on the road. Anthony thought if I can add in 5 degrees of timing, I'd be looking at around 50bhp going by how it was reacting to ignition advance on the dyno.
Here is a video of it on the dyno. The second part is Anthony doing short bursts trying to get the PID control dialled in, there was issues with boost spikes on gear changes before. It felt quite violent in the car but doesn't translate to video that well.
https://www.youtube.com/watch?v=OFMSHfdDhqg&lc...
t show so I wasn't overly confident. First run, at wastegate pressure made 300bhp, not a bad start. Second run which is where I'd got it to on the street made 370bhp at 1.2 bar. I'm starting to feel confident, Anthony the tuner starts sorting out the boost control, ignition and fuelling. It's then at around 380bhp, we start upping the boost but it's not responding how I'd expected, getting small bhp gains for the extra boost rather than large jumps, it got to the point where adding 0.2bar made no difference at all. I was hoping for 450bhp without meth. I've ended up with 404bhp. I couldn't get the meth working, a pipe kept popping off. I also had a boost pipe come off twice but other than that the day was problem free. There is obviously a restriction somewhere. Not sure what, the turbos are Chinese specials but they were making the boost and holding the boost to the redline so I think they weren't the issue. The egt's were good so don't think there was a problem with the exhaust size. The charge coolers might be restrictive but they came off a 600bhp Mercedes so I'd assume not.
I'm thinking it might be a combination of the boost pipes being slightly small and the route from the turbos to the inlet manifold having a few 90 degree bends. The exhaust also has a few 90 degree bends in it.
Here is the dyno graph, 404bhp, 470ft/lbs. I was told that other cars often make 20+bhp on a different dyno. Anthony spent a lot of time on the boost control and power delivery. I thought it best to get it coming in progressive rather than a huge slug of torque as I'm rear wheel drive. I've only driven it home, it drives much nicer at low RPM now, the extra ignition timing has made a big difference. It was busy and wet so only pinned it once. I'll be honest, I'm a bit underwhelmed. It feels fast but I think the car hides the speed quite well, combination of being heavier and more refined than previous fast cars I've owned. I'd been driving it around at 370bhp thinking it felt like 300bhp so I guess the extra 30bhp was never going to set my world alight. It's fast and I'm happy, need to drive it properly to form an opinion. In retrospect I think I prefer my power delivery a bit more savage, my friends S4 that's a similar spec feels like a kick in the b
ks when it comes on boost. This is the meth pipe that failed, the T-piece wouldn't hold the pipe. It's been fine before, typical! Good job it's a 50/50 meth/water mix, methanol would have caught fire squirting all over the exhaust manifolds.
I got home and found I've got an oil leak again. Yay!
The plan going forward is to get the methanol injection going and add some timing back in. My knock control is all set up now so it'll be something I can do on the road. Anthony thought if I can add in 5 degrees of timing, I'd be looking at around 50bhp going by how it was reacting to ignition advance on the dyno.
Here is a video of it on the dyno. The second part is Anthony doing short bursts trying to get the PID control dialled in, there was issues with boost spikes on gear changes before. It felt quite violent in the car but doesn't translate to video that well.
https://www.youtube.com/watch?v=OFMSHfdDhqg&lc...
Not as familiar with highly-strung turbo petrol though have built a couple of fast diesel. Does turbo petrol require any back-pressure like a naturally aspirated engine? I know a turbodiesel will run best with a straight pipe straight out of the side of the turbocharger and that's it. I know that sometimes it's a poorly matched intercooler setup that holds back something that's got a high boost but pumping fuel in and not getting the expected result. Obviously, charge coolers are a compromise. What boost level was the Mercedes they came off making? If it was a Kompressor, they run a quite low boost compared to a turbo and they might be a restriction. Why don't you get them tested? I'd still call that result impressive, apparently Nat. Asp camshafts help to wake those engines up too, I remember reading about Neil Purchase (TSR) and his 450bhp front-wheel-drive Passat B5 with a 2.7 in the front.
shalmaneser said:
400bhp sounds like a bloody respectable number to me! Driving home in the cold and the wet is never going to be the best way to experience some decent power, you wait until the roads are dry and empty and with the top down the experience will be quite different I bet!
Yeah, it's true, I can't make any judgement calls on it yet. Hopefully this weekend is nice and I can see what she's all about. mercedeslimos said:
Not as familiar with highly-strung turbo petrol though have built a couple of fast diesel. Does turbo petrol require any back-pressure like a naturally aspirated engine? I know a turbodiesel will run best with a straight pipe straight out of the side of the turbocharger and that's it. I know that sometimes it's a poorly matched intercooler setup that holds back something that's got a high boost but pumping fuel in and not getting the expected result. Obviously, charge coolers are a compromise. What boost level was the Mercedes they came off making? If it was a Kompressor, they run a quite low boost compared to a turbo and they might be a restriction. Why don't you get them tested? I'd still call that result impressive, apparently Nat. Asp camshafts help to wake those engines up too, I remember reading about Neil Purchase (TSR) and his 450bhp front-wheel-drive Passat B5 with a 2.7 in the front.
You don't want any back pressure on a petrol turbo either. They are off an S600 V12 twin turbo, not sure on the boost levels, think they are about 18psi. I'm running low 20's. They actually performed really well on the dyno from a temperature point of view. Last time I was seeing temperatures over 70 degrees, these were typically 25-35 degrees, multiple back to back pulls with no recovery time got into the mid 40's but the coolant temperature going into them was in the 30's.You're right about the naturally aspirated camshafts being an upgrade, I had 2.4 cylinder heads and cams, (the heads have larger inlet ports) on my previous Boxster that burnt down. Can buy a whole engine for a couple hundred quid.
Evoluzione said:
I take mine to a Dyno Dynamics, in the right hands they're very accurate so your figures are likely to be honest, not low.
When we get on the straight at a Trackday it's quite clear who's been fiddling the figures
Yeah, this is true, it's silly to be hung up about figures, it all depends on how it performs. When we get on the straight at a Trackday it's quite clear who's been fiddling the figures
Escy said:
Evoluzione said:
I take mine to a Dyno Dynamics, in the right hands they're very accurate so your figures are likely to be honest, not low.
When we get on the straight at a Trackday it's quite clear who's been fiddling the figures
Yeah, this is true, it's silly to be hung up about figures, it all depends on how it performs. When we get on the straight at a Trackday it's quite clear who's been fiddling the figures
Yeah, Indigo GT will be my default place, they are only around the corner so I can get a taxi back when it all goes wrong! I don't think I'll need to go back for any further tuning, now the knock control is setup I'm safe to sort out the meth and I think I might add a second boost table where the ramp up is more aggressive so I get the torque spike you feel in your guts, it's missing that drama.
They often do dyno days so I might go to the next one after I've made some changes and see what difference it makes.
The ecu has a performance calculator, the figures aren't that accurate but it's consistent so I can log my changes and should be able to see how much improvement I'm getting.
I'm really looking forward to next year now.
They often do dyno days so I might go to the next one after I've made some changes and see what difference it makes.
The ecu has a performance calculator, the figures aren't that accurate but it's consistent so I can log my changes and should be able to see how much improvement I'm getting.
I'm really looking forward to next year now.
Escy said:
I'm really looking forward to next year now.
That is good news!!Congrats! - Enjoy!
Randomly, you mentioned you might be thinking you are getting restrictions somewhere - are there any access holes in the inlet side, just before the head, where you could plug in another pressure sensor? - then you could compare pressure coming out of turbo and pressure at inlet valve, run those through a graph and see if you are getting a restriction?
(Peanut Gallery says, whilst the only thing he manages to do to his stock car is plug a charger in occasionally)
It would be interesting to log boost numbers at the manifold - could you use the fuel pressure regulator vac lines?. Is the fuel pressure good? Can you log that?
I like that from the outside it looks like a standard car but it can keep up with a 997 turbo!
I like that from the outside it looks like a standard car but it can keep up with a 997 turbo!
Edited by shalmaneser on Tuesday 10th November 12:58
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