Porsche 944 turbo road to racecar.

[Race Spec]

I reckon the EFR is the biggest win moving forward. Far greater boost recovery/transient response due to the lighter turbine wheel will 'almost' negate the requirement for a dog dox.

Granted, I have a PPG dog box in my car, and the difference is noticeable, not only in strength, but straight line performance.

[I'm DJ!]

As we're probably sticking with the stock box (which has given us no problems so far) I'm wondering if we shouldn't open it up and get the innards shot peened / Cryo'd etc ???

Which box is it Pat? The 968 or 944 t or are they the same? While I'm at it and in one post is the 968 and the 944 vs the 944t at all similar to the 924 or 924t gearboxes?

[333pg333]

Ours is the 968 6 speed which is a version of an Audi O1E box. The stock gearbox was a 5 speed. I actually much preferred my old 5 speed for shifting. No, the 924 box was actually a 915 box flipped around. Hence 1st gear is down and to the left.

[333pg333]

So the turbo turned up last week. Having made the new headers up with new custom flanges and the double bungs for EGTs and Lambda, plus coating them...they're now useless without ever having firing up the motor yet. Problem is that with the twin scroll we need cylinders 1-4 and 2-3 to be tied in together to then run off to the turbo as twin X-overs. Currently, the new headers have those cylinders joining into the collector diagonally and therefore it won't work. Fucken...

[Roadsailing]

So the turbo turned up last week. Having made the new headers up with new custom flanges and the double bungs for EGTs and Lambda, plus coating them...they're now useless without ever having firing up the motor yet. Problem is that with the twin scroll we need cylinders 1-4 and 2-3 to be tied in together to then run off to the turbo as twin X-overs. Currently, the new headers have those cylinders joining into the collector diagonally and therefore it won't work. Fucken...

can you swap two primaries?

[333pg333]

I doubt it. Car was up on hoist when we thought to look the other day. If it's possible we'll do it but I highly doubt it. Nui$ance.

[Roy928tt]

John Kuhn and co. have got their 928 S4 back on the dyno after optmising the entire system and a fresh motor with a little flow work, early days but they are at 10 psi for 540 wheel hp on a super conservative tune with 93 octane....talking about going to 30 psi on race fuel!!!

[333pg333]

That's super impressive for 10psi...they are US horses though. Smaller, but more of them. ;-)

[morerevsm3]

Dynojet wheel hp =~ flywheel hp

Sent from my GT-I9305T using Tapatalk

[Roy928tt]

They are on some sort of hub dyno that they bought for the purpose.

Knowing John, even the numbers will be conservative...

[333pg333]

From what I gather hub dynos read a bit more like crank hp. But nevertheless...540 anythings at 10psi is really impressive! Do you know what capacity that motor is Roy?

[Roy928tt]

I understand it is still 5 litre.

Hub dyno, no issues with wheelspin...it is just a passing number anyway. The old configuration pulled 711, the question is, What will be the next limiting factor? the turbos were all in @ 711. Now they have fitted physically the biggest turbos they could, into the space available (and upsized all the plumbing and cast exhaust manifolds and moulded silicon hoses etc etc) and are thinking they may run into a restriction in the stock inlet manifold or a pulse issue in the exhaust manifold?

John is rather anal, they have sensors on everything, even crankcase ventilation flow....

He believes he is delivering a product of Porsche quality to compliment the existing machine...I wouldn't dissagree.

[333pg333]

Sounds comprehensive. 540hp at such low boost would be tempting not to push it too much more on a regular basis just to get that 'factory' like longevity. I'd be happy with that at 20psi. Happier if it was 15-18psi but that only seems to happen on overseas cars.

[I'm DJ!]

Sounds comprehensive. 540hp at such low boost would be tempting not to push it too much more on a regular basis just to get that 'factory' like longevity. I'd be happy with that at 20psi. Happier if it was 15-18psi but that only seems to happen on overseas cars.

I reckon you'll be surprised with your new setup Pat. Fingers crossed.

[Roy928tt]

I reckon you'll be surprised with your new setup Pat. Fingers crossed.

My sentiments exactly