333pg333

I'd forgotten about that. A somewhat inglorious end.

Chris, how do you think the results might have been with a stock intake? I would have thought with that 'X' series GT35 and the short runner SFR intake that you may have seen more of a steeper curve with later onset.

blade7

That's what Master Po does to you when you give away Shaolin secrets .

Dutch944

Did Chris want to reply on this question?

Chris White

I can cover it again if you want!

I have posted many times before that the stock intake is a very good design and I have used it to make lots of power on other engines. I use the SFR intake on my 16v projects because of the need to adapt to the 16v head.

For this project the Owner had already bought the SFR intake.

From a practical "real world" stand point intake tuning does not have a great effect on the onset of power, that is dependent on turbo spool up - that is much more dependent on turbo design and then ignition/fuel tuning and cam timing.

It would be interesting to do testing on the intake with out a turbo and see the differences. If I had lots of time I would love to develop an engine (intake, headers, cam, ignition) as a normally aspirated and then add the turbo (and of course retune it again!).

gruhsy

When I win the lotto I help fund that

Thom

Would you say that the stock intake would have net the same results on blitz's car as with the SFR intake?

Chris White

I would be surprised if there was a significant difference between the SFR and stock intakes (I don't know Blitz's engine details of the top of my head!). The stock intake is rarely the choke point on a 944 engine.

when looking at an engine project as a whole I would recommend taking the $2k +/- cost of the SFR manifold and spending that on some real quality head work.

Dutch944

Oke thanks for the info.. As usual..

So how about a 16v manifold? At this moment i just want to cut off the some of the standard runners, weld a flange onto them with some trumpets and than create a collector!

Chris White

The stock 16v manifold is obviously not going to fit unless you relocate the turbo. Using the head flange and the first 4-6 inches of the runners will give you a good place to start....that's exactly what SFR does on the 16v manifolds.

Thom

I'm surprised to hear you say this. There is no way the stock intake will perform as well up top as a shorter runner intake, all other things being equal.

Have you actually ever done back-to-back testing between the stock intake and another one with shorter runners on the exact same engine?

Chris White

No, but you can tell from the shape of the torque curve if the VE is falling off at higher RPM - and on similar engines the shape of the torque curve on an SFR and a stock intake are not very different.

Keep in mind that I am not talking about 7k rpm engines, up to 6k the stock manifold will not be the limiting factor.

Above 6k you are more likely to run into turbo efficiency fall off and cam/head flow issues than a tuning from the stock manifold. Are you concerned with a 5-10 hp difference at 6400 rpm? I'll gladly toss that out in order to get better mid range performance!

Thom

Ok, I get your point, but I am pretty sure the curves here would have looked much different up top with the stock intake, especially considering how much of a large frame turbo the GTX3582R is.

Dutch944

Oke, so what i'm going to do is just the same as what everyone else does!

And ofcourse i know this will not be the perfect intake manifold.. I don't have the resources nor the skills to build it!

nick_968

It is an interesting point and a shame that to date no one has done back to back testing on different intakes to show what works and what does not. GIven they are not that hard to swap over it would be interesting to see the actual results, especially on a 3.0.

Voith

Porsche tested it. I bet the first thing they did, was bigger version of 924 turbo manifold, but that somehow did not work as it was supposed to, then they experimented a lot more.

I mean you have to get creative to develop something that looks like 951 manifold. I wonder how many man hours were spent on that piece alone.