Does anyone have any data on switching from various exhaust configurations ? I am trying to determine if the stock catback is really a power robber, as I would like my car to be quiet again. My guess is the biggest gains are found by replacing the catalytic converter with a test pipe.

If you have data on various exhaust changes, please share...

 

I saw a thread that it robbed about 15whp for one and as high as 25whp at a 350whp level. It convince me to go cat back with a "quiet" kinda upgrade. Love the stock CB for noise level thought.

 

You could do cut outs and stock exhaust. Is that what your thinking? I've thought about it...

 

I run 3" downpipe, 3" test pipe w/ electric cutout, and stock catback.

With the cutout closed, I lose 500-600rpm of spool and 2psi of boost, especially in the upper RPMs.

In fact, with a turbo as big as mine, I really hate driving my car with the cutout closed because the power takes forever to come on.

 

I noticed a big difference from stock to 3" rmr dp, mil spec cat, rmr catback setup. my exhaust setup is not overly loud or ricer like although Im sure its not the best for hp since it has 2 resonators.

 

a little off topic.. but does anyone run custom piping for their exhaust

 

I currently have an exhaust that is TOO QUIET for my tastes. What is a good exhaust to switch to that is louder and has decent power gains?

 

ughhhh...please only post if you have data or relevant commentary...

If you want a LOUD exhaust that is free flowing, get the Buschur TBE...

 

I had trouble getting above 18-19 psi on the stock catback with muffler removed and the stock cat on 91 octane. The car acted as though it was getting reversion contamination likely from high exhaust back pressure.

Probably not as bad of a problem on higher grade gas, but it limited the car considerably on 91 octane.

 

i was running hks carbon-ti and when my baby was born i decided to put the exhaust back on. according to dyno results I lost 30whp/trq. huge loss in my opinion. bushur TBE w/ magnaflow muffler is coming in next for me.

I dont think its worth it to put back the stock one

 

Interesting. Did you go from test pipe to stock catalytic converter when you went back to stock ? I am trying to figure out if most of the gains people see are from the popular test pipe route or that truly the catback is restrictive.

Thanks!

 

I've been reading this thread with some interest, as I'd like to quiet-down my exhaust, as well. It's a Works TBE w/HFC. It's not very loud as 3" Evo TBEs go, but it's a bit louder than I'd like. I've often thought about reinstalling the factory intermediate pipe.

 

3.5" ETS FTW! 100hp increase

Mikey

 

The Works TBE is as quiet as it gets for 3" TB. Mine with the Resonated test pipe is stock quiet while cruising. But a little loud at WOT.

 

I lost roughly 2 PSI which equated to 30 or 40 hp peak on the VDR swapping my Trust Ti catback to an Apexi GT catback. Note my car was tuned on the Trust, not the Apexi and no, I'm not kidding. I then put on the stock cat for emissions check up purposes and lost 2 PSI another 45 hp on the VDR. I went from 25 peak holding 22 at redline to 21 peak holding 18 at redline with the Apexi and stock cat...it SUCKED! I put back on the test pipe and Trust and it was like my car woke up again. Let this be a lesson to those swapping exhausts without retuning. It could be partially due to the Apexi having an extra resonator mid way in the cat back and the Trust is just a straight pipe with 1 45 degree bend to the muffler section.

Also, the Trust Ti is L O U D!