4dek

can anyone tell me if i need to have the car retuned if i switch back to my oem muffler which is obviuosly more restrictive than my turbo muffler? anyone pls help>>>>

jDMJeRk

absolutely.
Your exhaust back pressure is going to be horrible.
You should only have 1psi of back pressure per psi of boost being ran.

Do you have anything to measure back pressure with?

2point2

I tuned by car without the exhaust and when I bolted the (2.5" w/cat) exhaust back on there was a huge difference.

4dek

i know there will be a huge difference in performance but im more concerned about detonation..any input anyone???

jDMJeRk

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 4dek &raquo;</TD></TR><TR><TD CLASS="quote">i know there will be a huge difference in performance but im more concerned about detonation..any input anyone???</TD></TR></TABLE>
I'm curious in why you would think back pressure would cause dentation...
(In for answers too..)

JShull

I wouldn't think that it would cause detonation at all. Look at the guys using a cutout. It goes from open DP to full exhaust with the flick of a switch. If anything I would think the car is just gonna run rich and lose some power b/c of the restriction.

4dek

i dont know if my tuner said less or more restrictive exhaust can make my car run lean or detonate. i just dont remember if he said more restrictive or less restrictive but i think he said more restrictive might cause it to run lean, but i think its the other way around or maybe i heaqrd wrong. so confused

LSTEG96

1. Tune car on open DP.

2. add exhaust

3. watch AFRs go down. ( a ~little bit)