Exhaust system questions

[fireman717]

So has anyone ever compared a dual exhaust system to a single and the resulting loss or gain in power. I am looking at a dual system with cat delete and would like to know if the resulting loss in back pressure(if any) would lose power and if I should stick with the single system.

 

[nickleinonen]

would like to know if the resulting loss in back pressure(if any) would lose power

backpressure decrease is good for power. the less backpressure you have, the more pressure differential across the turbine you will have, resulting in good spooling. if you loose the exhaust velocity though [like going to a 5" or dual 4"] you might loose something some say here, but i know i didn't loose any by going with a 5" system over stock 3. 5". just go with what fits well and looks good to you ...

 

[RMarkey]

from what I've heard, most people with moderate mods have good results with a single 4in system. I did, except for the black soot all over my fender and bumper from hwy driving. The bumper actually looks blued around the soot from my last trip, I think it'll come off though, I hope. I'd get a tip and extend the stock pipe out a few inches. I just deleted the cat, and swapped in a high flow muffler and was good to go. Cheap, easy, good sound and results. Just my . 02

 

[JCleary]

You may see a loss on the dyno, but on the road I think you'll see a benefit in having a free-flowing exhaust.



The open exhaust will let your turbo spool faster than the ECM wants to see it spool, so the ECM will defuel a little to bring your boost back in check.



Once you've achieved max boost, however, you'll see lower egt's (usually) if you're towing something.



As soon as you add a box with boost fooling, you'll get the power back.



In my experience it was a net loss of 1 hp on the same dyno, but on two different days. It could just have been a difference in the weather.