bader$

I would be interested in a before and after dyno run. And I think the most restrictive part would be the air flow meter.

white924s

With manifolds, one not only needs to consider restriction but also volume of the manifold. A larger volume manifold will produce more power, but at the expense of decreased throttle response.

If the S2 and 968 manifolds were adapted to the larger engines, then I imagine that they would have slightly larger displacements, so you might get some more power there

oh and as far as I know, any manifold for an 8v engine will fit an 8v head and any 16v manifold will fit any 16v head, but you can't do any combo of 16v and 8v (ie 16v mani on 8v head won't work)

PorscheDude1

IIRC, it was to help get to the engine to operating temp faster and also to keep the TB from freezing in the winter.

FRporscheman

Yes, the S2 and 968 throttle bodies had coolant running through them to keep them from freezing. I live in California so I bypassed that throttle heater with a simple plastic coupling.

The 968 intake has annoyingly poor throttle response. Just warning you; don't be surprised if it feels like turbo lag. I'd love to see/hear your results using it on an S motor!

944CS

when the ambient temperature is low the air traveling through the throttle body can freeze and cause a sticky throttle. Also, the hotter air raises combustion temps which heat up the catalytic converter faster.

FR, the 968 dual resonance manifold was designed to increase low end torque while maintaining high rpm horsepower. Is your intake modified in any way from stock?

JakeS2

The stock S2 intake manifold has an intake air warming system. It's done by running coolant through the manifold. If the car is not used in winter situations, can be safely bypassed. This gives some 3-4hp.

jstand22

Woof123 are you interested in the manifold at all?

Raven951

of course everyone would love a before and after dyno. that's just how it is. but do you want to put your time and money into it? thats why their are so many secrets in the 944/951/968 racing world. also, thats why new ideas are never tried, too many people think they know everything, and made stupid comments about something they "think" they know, so no one else will try because "someone with a lot of posts said it won't work." people need to start thinking outside the box.

the air flow meter is only restrictive on partial throttle. At WOT it can flow as much as any MAF.

JakeS2

Raven, the AFM's problem is not the flow, but the way it operates. Therefore it can never be as fast and reactive as a MAF. It does not matter how much CMFs you run at high RPMs it it takes forever to get there, on track you don't have the luxury to wait for it.

If you really want to tweak the system, you are looking at aftermarket MAF and WB lambda so you can get the AF/M ratios from the whole range. Car's performance is a sum of components, exhaust, intake and timings. If you modify any of these you need to know what is the consequence on the others. On 944S and S2 the exhaust manifold is already pretty good (hence; not much aftermarkets available). Still, the only good advice I've heard is to bypass the coolant flow thru the manifold. If you want to improve the intake manifold, you're looking at a real throttlebody system with flaps per tube. In this case you need to build your plenum yourself.

If you really really want to get everything out from your car you're looking at standalone system such as Vems. There has been lately some good progress there and it's not that "hard" after you look into it.

FRporscheman

Everyone says 968s have lots of low end torque. But when you drive one daily, the off-the-line performance becomes infuriating. From idle to about 2000rpm the car feels like a diesel. I know what low-end torque is - it usually comes attached to a v8. The 968 feels more like a turbo car than a v8... if anything. And my manifold is stock. The entire engine is stock except the throttle heater bypass and a cone air filter (the airbox felt the same).

fortysixandtwo

The 968 has larger runners (cross section) and consequently larger intake openings in the head than the 944S2, I'm sure the same is true for the 944S. Just keep in mind that you might have some extensive port matching in your future.

DarylJ

That's what I though when I went out to look at a 968 that was local to me for someone on the list. Around town, I think I'd rather my 85.5. I was wondering if that was typical or if the 968 I was driving had issues.

FWIW, it was real nice at the top end.

PorscheDude1

a couple pics of the 968 intake.
IMHO, it may have have too much volume for a 2.5

bader$

I wasn't trying to say it wouldn't make an improvement, it's just so many things say this and say that but the proof is what shows up on the dyno. If I had a manifold from either a 968 or an S2 I would try it. I wasn't trying to discourage him. I am simply interested in the results.

As for the "I think" comment about the airflow meter, I only say that because it is the smallest passage in the intake tract. I never said I was an expert

Raven951

#1, a plug and play MAF already exists...the scivision maf and vitesse offers one as well. getting an aftermarket maf, and using a piggyback is NOT the proper way of doing things. more than likely vitesse is the only company offering a TRUE mass air conversion. the scivision maf uses a resistor so the dme can read proper voltage.

#2, to say that the 16V exhaust manifold is pretty good is a J.O.K.E. Their is so much more left to be desired. The Michael Mount/Stahl header is the best out there, PERIOD. The HP gains with this particular system is incredible and is what makes your statement laughable.

#3, to even suggest an ITB system is useless. The system would cost more than the car, and only handful of people have ever done it.