Phoenix from the flames - Porsche Boxster with an Audi 2.7T
Discussion
Peanut Gallery said:
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)
Thanks. I don't think I've got the stomach for more messing about, I've not got any spare analog inputs left on the ECU either. Let's say the coolers were a restriction, I'm not going to replace them anyway so no point digging too deep into it. 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)
shalmaneser said:
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'm taking my MAP signal from the back of the inlet manifold. The fuel pressure was good, injector duty cycle was only 80%, plenty left in it on that side. 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
I also like the fact it looks like standard. I'd like to try and go to a track day put on by Porsche owners, it would be nice to reel in a few of the fancy expensive ones.
mwstewart said:
That's a good result. Just a word of warning on the brake caliper mounts: if the material is 'generic' aluminium then it is unsuitable. It should be something like 7075 or ideally 6061 - both in T6 spec.
Thanks for bringing this up. Since I'm using a big fat chunk of it I hadn't given the material grade the consideration I should have. It's 6082T6, which seems to be near enough a identical to 6061T6. The main distinction seems to be the 82 is more readily available in Europe and the 61 in the US. Escy said:
Thanks for bringing this up. Since I'm using a big fat chunk of it I hadn't given the material grade the consideration I should have. It's 6082T6, which seems to be near enough a identical to 6061T6. The main distinction seems to be the 82 is more readily available in Europe and the 61 in the US.
Yep, that's good 
Following on from the day at the dyno I haven't used the car much other than taking my old man and brother out in it, there were a couple of things that needed sorting out.
Easy one first, replaced the leaking push fit T-piece on my WMI system for one from Aquamist that is screwed tight. I do like the stuff they sell.
Next job which should be easy is re-sealing the leaking sump. I'd had 2 unsuccessful goes with silicone. Spoke to Audi/TPS and they can't get a replacement gasket anymore. The OEM was just a paper gasket. I bought one on ebay, this is a pressed metal gasket. Fitted it and...
It leaked again
. I'm not sure why this is proving to be so difficult, didn't seem to leak from the same place as before. I've had to do it again, this time with a different silicone and I used it both sides of the gasket. I haven't run the engine since doing it but so far so good, I think it's sorted.
Another issue seems to be my gearbox mounts, the old ones sagged a bit on the nearside mount so I replaced them with DesinTek mounts. I noticed the bracket that holds them wasn't perfectly straight and this DesignTek one had dropped a bit also, I added a washer behind the bracket on the gearbox end to straighten it out as a temporary thing for the dyno. By the end of the day it had dropped some more (every time it drops the gearbox comes into contact with the cross member running under the car). I took the mount off again, cut the bracket I made up and re-welded it. It's dropped again since, it's fine when it takes the weight of the engine/gearbox but after a drive it looks like it settles a bit lower so I'm going to do it one more time, accounting for this. Sick of the bloody thing. Not overly impressed with how the mount has opened up on one side, they weren't cheap.
Having looked at the logs from the road I've noticed the car isn't making the targeted boost pressure.
The boost control is closed loop so it looks at how far you are from your boost target and it uses PID settings influence how it makes adjustments to bring you onto the target. It should see that the boost isn't where it should be and make changes but it's not trying. The green line should be sat on top of the redline which is my boost target.
The control loop works off your base duty table settings (this is the % of duty cycle the solenoid requires to reach a boost level). This base duty table was set really close to the correct values then the PID settings were tuned to to get it perfect, I was watching and it was absolutely bang on the boost target.
The difference from being on a dyno with a simulated load to being out in the read world has changed the way the car builds boost. The PID has been tuned too tight to the base duty table so it's not even trying to make up the difference now the gap is larger. I think maybe the tuner went down a bit of a rabbit hole getting it to track accurately. I'm going to raise the base duty cycle table up to get it to match, I'll then keep an eye on it to make sure it's doing it's job with seasonal changes, if no I'll have to change the PID settings myself to make it work over a larger range.
What this shows is, if you buy a standalone ECU, pay for someone to tune it and don't really understand how it works yourself and you don't look at logs you could well end up with issues like this that go undetected.
The good thing is, it was feeling plenty quick as it was at the lower boost. Nice to know there's more in it, plus more again when I run the water/methanol injection and increase the ignition timing.
Easy one first, replaced the leaking push fit T-piece on my WMI system for one from Aquamist that is screwed tight. I do like the stuff they sell.
Next job which should be easy is re-sealing the leaking sump. I'd had 2 unsuccessful goes with silicone. Spoke to Audi/TPS and they can't get a replacement gasket anymore. The OEM was just a paper gasket. I bought one on ebay, this is a pressed metal gasket. Fitted it and...
It leaked again
. I'm not sure why this is proving to be so difficult, didn't seem to leak from the same place as before. I've had to do it again, this time with a different silicone and I used it both sides of the gasket. I haven't run the engine since doing it but so far so good, I think it's sorted. Another issue seems to be my gearbox mounts, the old ones sagged a bit on the nearside mount so I replaced them with DesinTek mounts. I noticed the bracket that holds them wasn't perfectly straight and this DesignTek one had dropped a bit also, I added a washer behind the bracket on the gearbox end to straighten it out as a temporary thing for the dyno. By the end of the day it had dropped some more (every time it drops the gearbox comes into contact with the cross member running under the car). I took the mount off again, cut the bracket I made up and re-welded it. It's dropped again since, it's fine when it takes the weight of the engine/gearbox but after a drive it looks like it settles a bit lower so I'm going to do it one more time, accounting for this. Sick of the bloody thing. Not overly impressed with how the mount has opened up on one side, they weren't cheap.
Having looked at the logs from the road I've noticed the car isn't making the targeted boost pressure.
The boost control is closed loop so it looks at how far you are from your boost target and it uses PID settings influence how it makes adjustments to bring you onto the target. It should see that the boost isn't where it should be and make changes but it's not trying. The green line should be sat on top of the redline which is my boost target.
The control loop works off your base duty table settings (this is the % of duty cycle the solenoid requires to reach a boost level). This base duty table was set really close to the correct values then the PID settings were tuned to to get it perfect, I was watching and it was absolutely bang on the boost target.
The difference from being on a dyno with a simulated load to being out in the read world has changed the way the car builds boost. The PID has been tuned too tight to the base duty table so it's not even trying to make up the difference now the gap is larger. I think maybe the tuner went down a bit of a rabbit hole getting it to track accurately. I'm going to raise the base duty cycle table up to get it to match, I'll then keep an eye on it to make sure it's doing it's job with seasonal changes, if no I'll have to change the PID settings myself to make it work over a larger range.
What this shows is, if you buy a standalone ECU, pay for someone to tune it and don't really understand how it works yourself and you don't look at logs you could well end up with issues like this that go undetected.
The good thing is, it was feeling plenty quick as it was at the lower boost. Nice to know there's more in it, plus more again when I run the water/methanol injection and increase the ignition timing.
Loving this project. Hope you'll start selling an adapter kit or the drawings.. 
Maybe take the WG boost signal from further downstream in the charge piping? Oh wait you must be using boost signal interrupt if you're controlling it from ecu never mind...
Also have you considered an electric pas pump? They're cheap these days used, just need somewhere to put it.
Also also, have you measured IAT in case the compressor is falling outside of it's map and you're just making heat with the extra 0.2 bar and no more power? Just a thought.
Beers!
Maybe take the WG boost signal from further downstream in the charge piping? Oh wait you must be using boost signal interrupt if you're controlling it from ecu never mind...
Also have you considered an electric pas pump? They're cheap these days used, just need somewhere to put it.
Also also, have you measured IAT in case the compressor is falling outside of it's map and you're just making heat with the extra 0.2 bar and no more power? Just a thought.
Beers!
Never looked into electric steering, people don't seem to like it on the newer Porsche's. The new hydraulic pump I fitted a month ago has solved my previous issues, it's perfect now.
I'm measuring the IAT just before the throttle body, there is a chance the turbos were being pushed too hard, we didn't see it in the IAT's but the charge coolers might have been doing their job so well it masked it. The boost levels are around what others run however. There was no power gain going from 2600mbar to 2800mbar on the dyno. I've bought a Dragy which is a GPS performance meter and apparently pretty accurate so i'll use that to show me the results of any changes.
I'm measuring the IAT just before the throttle body, there is a chance the turbos were being pushed too hard, we didn't see it in the IAT's but the charge coolers might have been doing their job so well it masked it. The boost levels are around what others run however. There was no power gain going from 2600mbar to 2800mbar on the dyno. I've bought a Dragy which is a GPS performance meter and apparently pretty accurate so i'll use that to show me the results of any changes.
On to the rear brake upgrade, this is proving to be more challenging than the fronts. The discs are 380x30mm which seems to be an uncommon thickness for a disc this size. After plenty of trawling the internet I decided on a set of Lotus Evora 400 rear calipers (made by AP Racing). They use a 350x30mm disc. I bought the only set of calipers I could find for sale, they were from a Lotus breaker who then informed me they couldn't find them on the shelf. I ended up waiting a few months for them to get another Evora 400 in for breaking. I was pleased when they turned up, they look like new.
I want to get all this sorted without taking the car off the road. The 987 hubs are different to the 986 I had available. Rob at 9apart has loaned me a rear hub I can use to mock up with. Very grateful to them for that. I was impressed with the hub when it turned up, it's an improvement over the 986 one, much lighter, it's hollow with air channels running through it. A lot of people write off Boxster's as proper sports cars due to the relatively low power but when you have a good look at the design and build of them, they are a legit bit of kit.
Starting to see how it's going to be. The bracket for this is going to take a bit more work than the ones on the fronts. The air channel coming out of the middle where the caliper bolts protrudes past the mounting holes. The bracket is going to be a lot thicker than the one on the front.
One thing I knew about before buying the calipers was the pad is slightly deeper than the disc surface, i'll need to take some material off the inside radius and have the pads flush at the top. That was another odd thing with these discs, large diameter but the actual disc surface was only 50mm deep which is quite narrow.
I needed some standard discs and didn't want to buy new, I put a wanted post on the Boxa forum and a member Philc sent me his old discs. Again much appreciated. I had a plan, I wanted to get the disc turned down on a lathe so i'm left with the middle bit which is a drum for the handbrake pads. I'd hoped this was going to fit inside the alloy bell on my big disc. It turns out the bell is exactly the same size and shape as the drum but stops at the point the handbrake shoes would be. This scuppers my plan to have the standard drum under the big disc.
You can see the difference in size between the 2 discs, it's massive but I think the larger disc is actually lighter.
I'm thinking my best option might be to get a drum made up, the ring on the back of the discs where the bolts go through could be replaced with one that's got a drum incorporated into it. Like my crude red lines try to show. My father in law who has an engineering company in Brazil is coming over for Christmas, i'm sure he'll want to get involved with this.
I want to get all this sorted without taking the car off the road. The 987 hubs are different to the 986 I had available. Rob at 9apart has loaned me a rear hub I can use to mock up with. Very grateful to them for that. I was impressed with the hub when it turned up, it's an improvement over the 986 one, much lighter, it's hollow with air channels running through it. A lot of people write off Boxster's as proper sports cars due to the relatively low power but when you have a good look at the design and build of them, they are a legit bit of kit.
Starting to see how it's going to be. The bracket for this is going to take a bit more work than the ones on the fronts. The air channel coming out of the middle where the caliper bolts protrudes past the mounting holes. The bracket is going to be a lot thicker than the one on the front.
One thing I knew about before buying the calipers was the pad is slightly deeper than the disc surface, i'll need to take some material off the inside radius and have the pads flush at the top. That was another odd thing with these discs, large diameter but the actual disc surface was only 50mm deep which is quite narrow.
I needed some standard discs and didn't want to buy new, I put a wanted post on the Boxa forum and a member Philc sent me his old discs. Again much appreciated. I had a plan, I wanted to get the disc turned down on a lathe so i'm left with the middle bit which is a drum for the handbrake pads. I'd hoped this was going to fit inside the alloy bell on my big disc. It turns out the bell is exactly the same size and shape as the drum but stops at the point the handbrake shoes would be. This scuppers my plan to have the standard drum under the big disc.
You can see the difference in size between the 2 discs, it's massive but I think the larger disc is actually lighter.
I'm thinking my best option might be to get a drum made up, the ring on the back of the discs where the bolts go through could be replaced with one that's got a drum incorporated into it. Like my crude red lines try to show. My father in law who has an engineering company in Brazil is coming over for Christmas, i'm sure he'll want to get involved with this.
Random thought, instead of using a drum for the handbrake, thereby blocking the air flow through disk, have you concidered a second caliper on the disk. This is the first ebay find, just to clarify my thoughts!
https://www.ebay.co.uk/itm/Wilwood-Mechanical-Hand...
https://www.ebay.co.uk/itm/Wilwood-Mechanical-Hand...
Escy said:
Never looked into electric steering, people don't seem to like it on the newer Porsche's. The new hydraulic pump I fitted a month ago has solved my previous issues, it's perfect now.
I'm measuring the IAT just before the throttle body, there is a chance the turbos were being pushed too hard, we didn't see it in the IAT's but the charge coolers might have been doing their job so well it masked it. The boost levels are around what others run however. There was no power gain going from 2600mbar to 2800mbar on the dyno. I've bought a Dragy which is a GPS performance meter and apparently pretty accurate so i'll use that to show me the results of any changes.
Sorry I should have been clearer, an electric hydraulic pump, powering the standard hydraulic rack..I'm measuring the IAT just before the throttle body, there is a chance the turbos were being pushed too hard, we didn't see it in the IAT's but the charge coolers might have been doing their job so well it masked it. The boost levels are around what others run however. There was no power gain going from 2600mbar to 2800mbar on the dyno. I've bought a Dragy which is a GPS performance meter and apparently pretty accurate so i'll use that to show me the results of any changes.
https://www.ebay.co.uk/itm/VAUXHALL-ASTRA-H-MK5-ZA...
Mounted in the frunk right next to the rack, 911 cup car stylee. Glad the issue is resolved now anyway.
Quite a few cars have a separate cable operated calliper on the rear discs for mechanical handbrake for MOT purposes btw.
Bullet-Proof_Biscuit said:
Quite a few cars have a separate cable operated calliper on the rear discs for mechanical handbrake for MOT purposes btw.
I've got a set of these http://www.hispeccalipers.co.uk//svabillet.html on my GT40, they also do similar "stand alone" spot calipers. http://www.hispeccalipers.co.uk//svaspot.htmlI am aware of these handbrake calipers but I feel utilising the original handbrake mechanism is going to be the easier and neater solution.
My brake discs are made by PFC for the 991 GT3 Cup Cars, they also made a street version of that brake set-up for TPC Racing (which costs $13,750). They've just made a drum on the back of the brake bell. Not sure if it's made from aluminium or steel, would expect aluminium to be dodgy if your handbrake was ever binding.
My brake discs are made by PFC for the 991 GT3 Cup Cars, they also made a street version of that brake set-up for TPC Racing (which costs $13,750). They've just made a drum on the back of the brake bell. Not sure if it's made from aluminium or steel, would expect aluminium to be dodgy if your handbrake was ever binding.
Quite a lot of cars had the electro-hydraulic system. Astra, Polo/Fabia/Ibiza. That one actually feels like standard hydraulic. Sits behind the ABS pump in the standard car. AFAIK can be run through CAN or independently (and think there are controllers which use a rheostat/potentiometer to control the level of assistance)
I actually prefer the electromechanical system in the Mk5 Golf etc, for feel compared to a "traditional" hydraulic system.
I actually prefer the electromechanical system in the Mk5 Golf etc, for feel compared to a "traditional" hydraulic system.
I know this is a little off topic but re. electric power steering, see here:
http://www.911uk.com/viewtopic.php?p=1514143
Basically it turns out the unobtainium RennSport RS GT whatever electric power steering pump (so a electro-hydraulic system) is the same one found in the Vauxhall Zafira and can be picked up for £30 on ebay should anyone be interested in a swap. Presumably the same system for the 9X7 as the 9X6 cars as the suspension is essentially the same.
http://www.911uk.com/viewtopic.php?p=1514143
Basically it turns out the unobtainium RennSport RS GT whatever electric power steering pump (so a electro-hydraulic system) is the same one found in the Vauxhall Zafira and can be picked up for £30 on ebay should anyone be interested in a swap. Presumably the same system for the 9X7 as the 9X6 cars as the suspension is essentially the same.
I've come up with a plan for the handbrake. Just before the start of the first lockdown I bought a pair of alloy brake bells that were custom made for a 996 GT3, I'd not done enough research before buying them, the discs they were designed to run are big money so I never bothered. I'd forgot I had them and found them while looking for something else. They weigh about 4 times more than the other bells I'm going to be using, you can see why from looking at them, they are a huge chunk of alloy. They happen to have big thick inner lip (don't know why as these are for the front) which happens to be the perfect for a handbrake drum.
The plan is to turn these bells down on a lathe so I'm left with a drum that will fit inside the 991 bell which I'll bolt to the back of the brake disc. My father-in-law is coming over from Brazil next week and this is his bread and butter so I'll get him to do it for me, my mate's dad has a lathe we can use.
The plan is to turn these bells down on a lathe so I'm left with a drum that will fit inside the 991 bell which I'll bolt to the back of the brake disc. My father-in-law is coming over from Brazil next week and this is his bread and butter so I'll get him to do it for me, my mate's dad has a lathe we can use.
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