Goddammit, stupid damn work internet connection...

For a 2.0L 420A with a S16G turbo setup, running up to 20psi and making up to 350hp, what kind of exhaust would you guys recommend? 2.5" dp -> 2.5" high flow cat -> 3" cat back exhaust? And why? I would use search, but my net connection keeps timing out (hell, even timed out when I first typed this post, see first sentence...). Help a poor bastard out who wants to learn!

-Corey

well, you only really have 2 choices: a 2.5" to 3" or a 3" to 3". Either way is goof for your goal. There is a new fad running around on the board for 3" DP's, which is primarily just overkill for 99.98% of the cars on here. Remember exhaust gas is condenced as it leaves the motor, it NEEDS to and will expand as it cools (hence 2.5"DP to 3" cat-back. you really dont need anything bigger than 2.5" for a DP(especialy when you consider that the opening on the hot side is only about 2 1/4"). you most definatly want a 3" cat back thou!!!

Wouldn't the laws of thermodynamics contradict that (gases expanding as they cool)? I know I need a 3" (or rather, it's optimal) for turbo, but I just want to understand it completely.

Thanks,
Corey

What's going to be the problem with running 2.5" turbo back exhuast with a high flow cat? I MIGHT upgrade to the S20G in teh future. If I stay with 2.5" from the cat back, will I run into any issues? The reason I ask is I have a connection and I can do a 2.5" turbo back setup for under $600, including all the parts (mandrel bends, high flow cat, flex section and muffler) and labor.

Well if you want the best bang for the buck, and ignoring the noise factor, 3 in is definetly the best way. I'd go with a 2.5 dp, like xtremers, with the 3 in hi-flow cat, and the 3 in cat-back.

A good compromise between performance and noise is the RsR Ex-Mag system. It is 2.75 in piping. http://www.geocities.com/MotorCity/Lot/3878/15.html I want this one!!!

-------jezreel
hrc stage 1, sfmu, ml, prokits, egt, boost gauge, apexi tt, turbo xs rfl, haydans tranny cooler, costum dp, dr. uber groundwires, dynotune fp gauge. gst muff, turbo spoiler

nothing like driving with the windows down and the music low: i love hearing the turbo spool, swwwhhhttt!!!!
thanks for www.kaptainmyke.com for the sig hosting :thumbsup

Get a 3 inch dp to a resinator to a fart can. That's what I have, exept I still have the stock hahn dp which I hope to replace soon. But that is the best setup for a turbo. If you live in a state with emissions testing your kinda screwed.

3 inch DP to race cat or test pipe to either 2.5 cat back or 3" inch cat back imo

2.5" downpipe is all you need on a S16G turbo. The actual outlet of the turbo is 2" in diameter. The efficient power range of this turbo won't even get close to needing a 3" downpipe. A 2.5" downpipe, using a 3" catback, would be optimal, for this turbo running at its maximum efficiency. Remember that the S16G starts to loose efficiency around 17-18psi..

that RSR exhaust is the old school version. Newer versions look a bit different. Performance wise, I think it is all the same. One chief complaint I have on the RSR is the piping that goes over the axle rather than under. There is very little room for clearance with the RSR street system.

On the subject of DP to Exhaust, the idea is to go small to big. Ideal piping diameter IMO for a street setup would be 2.5" Dp to something bigger than DP diameter. If a 3" can fit, than by all means, however I do not see the need for a 3" downpipe on a 4 cylinder street car.

i have a 2.5" DP to testpipe, then from there back is 3". works fine for me.


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