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I should add mine to the list. too. Here are the engine basics, the big list is way too long!
S2 engine with Pauter rods and custom 9:1 arias pistons.
Modded 968 intake manifold that I bought used.
SFR front mount intercooler
SFR stage 2 headers, crossover.
Precision 6062 turbo.
Megasquirt MS3x engine management.
I have had a new intake manifold made for my 16V engine. It was optimised on a flow bench with the runners ending up flowing 351 (+-5) cfm each, which I think is pretty good as I believe a bone stock 968 head flows ~300 cfm at stock intake valve lift. A second unit is under way for a friend.
Bellmouths shaping :
Powder coating :
Ready to fit (the carpet is not for sale) :
Up and running :
That looks good Thom. I'm sure it will help your motor. Especially in the upper rpms.
Thanks Patrick. I think it would have been difficult to come up with a better intake considering all packaging constraints. I am also pleased I carried on with the old school Audi 20V throttle body which mechanical features help with smoothening on/off idle and fuel cut transitions, particularly with the slightly heavy TTV flywheel. Injector duty cycle suggests I am currently at only ~350 rwhp with 0.5 bar of boost, but how the engine is eager to build revs make it enjoyable in a way the 8V engine never was even with perhaps 100 more hp, and this has been the point in buidling a 16V engine in the first place - as you know there is just no replacement for VE. It has been a tedious year with little driving time between tunneling for work and the various lock downs but hopefully I will have some proper time to tune it in the coming weeks. The lack of driving time and the 16V engine feeling so different from the 8V engine make the car feel like nearly new to me, which is a breathe of fresh air after going over the deep end modifying it, and I look forward to discover what it will offer with more boost.
Originally Posted by JustinL
S2 engine with Pauter rods and custom 9:1 arias pistons.
Modded 968 intake manifold that I bought used.
Nice build. Are you using an S2 head with the 968 intake flange?
Well, we have a jig to make further 16V intakes like mine, either with an S2 or 968 flange. Just drop me a line if you are ever interested. We just need the dimensions of the throttle body that would be used.
FWIW initially I was lent an intake using an S2 flange to get my 16V engine running and could hear some extra ticking noises with the J&S Safeguard, and that was not knock. Perhaps the turbulences caused by the step between the intake and the head caused some pre ignition. These parasitic noises are now gone with the new intake and the engine is safely tunable.
I can't imagine how it's been for you in France / Europe...basically anywhere else but Down Under!! Glad the new motor has revitalised your experience with the car Thom. What are your plans for boost increases?
Well, the plan is to increase boost until finding the sweet spot, ie a good balance between peak boost, a "reasonable" ignition profile and an exploitable torque delivery with "reasonable" IAT and EGT levels. Not really sure where I am headed, but between the low-ish geometric compression ratio (with Variocam on) and the closed deck there may be plenty of room for more than 1.5 bar of reliable boost. 0.5 bar is as much as I have tested so far and without much surprise the stock intercooler already feels like it's on its knees, and, knowing that it will definitely not let the engine give its best, trying to work my way around it somehow is already a challenge interesting enough to me. I have plans for a special intercooler further down the line but since working with the tune remains to me the most enjoyable part of such a project and has been so since I have been tuning this car myself, I want to try to make the best of the current engine hardware first.
Well, the plan is to increase boost until finding the sweet spot, ie a good balance between peak boost, a "reasonable" ignition profile and an exploitable torque delivery with "reasonable" IAT and EGT levels. Not really sure where I am headed, but between the low-ish geometric compression ratio (with Variocam on) and the closed deck there may be plenty of room for more than 1.5 bar of reliable boost. 0.5 bar is as much as I have tested so far and without much surprise the stock intercooler already feels like it's on its knees, and, knowing that it will definitely not let the engine give its best, trying to work my way around it somehow is already a challenge interesting enough to me. I have plans for a special intercooler further down the line but since working with the tune remains to me the most enjoyable part of such a project and has been so since I have been tuning this car myself, I want to try to make the best of the current engine hardware first.
That's a juggle but a good challenge for someone like yourself. It will be interesting to see how you solve the I/C issue. Have you modified yours at all? Associated plumbing still stock?
Long time gentlemen I have two questions, I’ve emailed and pm Jim or oddjob as we have done business with parts in the past and have talked over many years back and forth. However in the last week both are bouncing back his pm box is full and email is not going through? Has anyone heard from him is he alright? I hope he is ok
second question is I have spoken to two member hers who have a very nice 968 turbo RS replica of the rare carbon fiber strut brace that was put together bye a 944 shop in Europe
I have tried several times in the last 6 months to contact him regarding these as in middle
of 2019 he said he was sold out but planning another run of them. I’m looking for one of these or equivalent.
It’s Patrick and he does do amazing work on 944/968 cars check out his Facebook page he has great I do and pics of projects on there I’m checking to see if he has any carbon strut braces available right now
It's been an awesome first DE season driving my 500 HP 3.0L turbo. I wanted to share my experiences for the year with anyone here considering building this motor for track use. It's a challenging driver's car and will keep you on your toes at these power levels.
The torque improvement over the 2.5L is amazing. The 86 turbo always felt lethargic off boost especially compared to say a Cayman. The 3.0L bottom end has plenty and for street driving feels just right. At the track, both cars are on boost where you don't notice it as much except for slow chicanes or AX style turns.
I worried that the GTX3582 gen2 would be too much turbo for this asthmatic 8v head but no. The power feels flat. The power band is right where I want it. No sudden boost issues in the middle of a corner. The turbine size and it's related back pressure are a limiting factor for this motor currently, but to go larger would just make the power curve less usable we think. It'd be hard to find a better match, but maybe the newer G series should be considered. I bet there is a good matching EFR as well.
I don't notice the conversion to an electronic throttle body at all. I was really concerned this would add lag or affect the purity of the driving experience but nope. I don't feel like I'm fighting the car at all. It just does what I ask when I ask it. I left a flat response curved programmed in.
I run about 400 wheel on 93 octane and 500 wheel on e85 and you can really feel the organ crushing difference. If I'm not careful, the wheels will spin in any gear except 5th on the corn juice. On pump gas the car eats base 997 GT3s no sweat. Power is great and for DE purposes I don't want to add any more. I may even turn the power down to give longevity a chance. The car is well behaved at 400, requires care at 500, but I wouldn't want to go much higher on R888Rs or other street tires. I have torque limiting functions enabled in the emtron which are there to prevent the transmission from grenading.
I'm using the webcam 274 and I was concerned about the slight overlap. I discussed with the tuner and the cooling effect of the overlap is beneficial in my case. The car runs HOT. At WGI, the motor spends most of a lap at over 1500F EGT, peaking to 1650. On a hot summer day, after 15-20m of driving, the car will over heat and I'll need to back off. This is with a giant custom aluminum radiator, and the lindsey 3x oil cooler, and the big garrett core FMIC. More work on front air ducting is needed for sure. And probably need more venting in the hood so the air has somewhere to go.
I asked the tuner about if the aftermarket intake could be a problem and if a stock unit might be better. The response was that the car makes great power as it is and that nothing stands out as needing to be changed. The limiting factors right now are EGT and exhaust back pressure due to the crossover pipe and general "wrong side" turbo layout of this car.
All the power is great but is showing the weaknesses of the chassis. High frequency wheel hop in the rear when the tires spin which happens on e85 if I'm pushing it. The car just can't brake anything like a modern car and on the 86 without ABS I tend to lock on occasion due to lack of skill, quick weight transfers from stiff springs, and the extra fast pace of this motor. Need to go to a slightly softer front spring to help give the brakes a chance I think.
We'll see what the longevity is like. I'm pushing 7200RPM. There's quite a lot of vibration around 3K with the balance shafts deleted. I had a weld failure in an aluminum expansion tank this year due to expansion and contraction, had a boost hose pop off, and had the driver rear axle nut lose torque. The starter heat shield vibrated, cracked, and fell off somewhere.
I was worried I made a mistake by not going the 16v route. But having e85 as an option seems to make up for it. I couldn't be happier with the power level. No doubt 16v is the right move if you want to max it out. I wouldn't shy away from the 8v path for a more budget friendly / less fabrication heavy kind of build though if you're not doing competitive motorsport.
04-27-2021, 03:16 PM
