Intake and exhaust options?

[Stuttgart951]

Looking to throw some more more air into the engine and make it easier to get out.

Does anyone have pictures/experience with aftermarket intakes and/or exhaust systems?

In terms of intakes - sound is not terribly important, Im just looking for the best breather. Exhaust-wise, Id like something thats sounds good, but without the "rice burner" buzzzy bumblebee sound. Is 2.5L of displacement enough to aviod this? If anyone has sound wavs of exhaust or just a muffler, please post them.

Thanks.

[Lawrence Coppari]

Are you talking about MAF's here?

[SoCal Driver]

I've thought about this too. Did a bit of research and figured that I could buy another 944 for what it would cost.

There is room for a tremendous amount of improvement. It's getting it to fit under the hood that is the problem.

A better flowing exhaust system, headers, to the CAT is a start. Then a higher flow CAT. At the end a through flow "glasspack" would be better than the mechanical baffled muffler.

The plenum based intake and it's long "runners" into each cylinder is optimized for a certain torque range. Like a pipe organ has certain sizes, diameters and lengths, to give a particular tone. Since the injectors are at the intake valve there is no need to have the old "cross ram" set up to keep the air/fuel mixture atomized. What would be really trick is a rapidly changing tube length to optimized the torque through out the speed range. Would have to move pretty darn fast though.

Increasing the throttle valve diameter and using a mass air sensor in place of the mechanical baffle should help. At least to clean up that part of the intake by removing mechanical parts.

Personally it's not about how it sounds, rather it's about optimizing the system using newer technology. Still a beefy sounding exhaust and a bit of cam lope at idle does bring back memories of the old 55 cheby!

[gforces944]

SoCal is right. It sounds like he's talking about Porsche's own VarioRam?, or Honda's VTEC system on the Integra, which uses a two stage manifold--but there are ways to improve performance without hacking up your car.

replace that barn door flap of an air flow meter with an MAF. Having your throttle ported and matched to your intake helps too. You can still use your stock exhaust with a higher flow header and cat--that way, you won't end up sounding like a CRX. However, it shouldn't matter since that turbo wouldn't let things get too loud to do it.

Porsche did a good job on the exhaust. I had the Borla system on mine, and reverted back to the stock one, because the gains didn't justify the expense of noise it produced. When I sat the two exhausts next to each other, the difference in diameter of the pipe from the cat to the muffler were apparent, the Porsche model was larger! I know a couple of guys that had that stock pipe welded to a new muffler as well.

Next time you do a clutch job, get a lightened flywheel. There's no better way to boost acceleration than to reduce rotational mass.

[SoCal Driver]

Here is a good technical description with illustrations:

http://autozine.kyul.net/technical_school/engine/tech_engine_2.htm

The variable lenght trick can be used with the exhaust too.

[gforces944]

wow, sounds very development intensive. I'd just slap an MAF w/chips and call it good.

[Lawrence Coppari]

Stock turbo muffler is a straight through design. You can stick a broomstick clear through it.

[Stuttgart951]

Thanks guys.

[JGriff]

Originally posted by Lawrence Coppari
Stock turbo muffler is a straight through design. You can stick a broomstick clear through it.

Do you happen to know if the one on an S2 is also? I'm planning on sticking a broom in it to check... but I figured I'd ask anyway...

Thanks.