Scenario:

i changed my exhaust set-up on my FD. after changing, my EBC dropped from 10psi to 7-8 psi. I had the BC re-learn and everything is back to normal.


does the evidence of the boost controller dropping boost, point to increased exhaust restriction or decreased?.....




after i see a few responses, ill tell you the reason im curious.....

 

did you switch from a stock precat to a open dp?
i would make sense if you did because of the backpressure produced by the stock precat.
when you replaced it with a dp that would decrease the back pressure therefor tricking the bc?

 

^ thats what im asking.



i know i changed the restriction. Im wanting you to tell me whether i made MORE or LESS restriction, based on how the BC reacted to the change.

 

The way I see it is that if you went from a free flowing exhaust to a more restrictive one then that may explain it due to the backpresssure building, but if you went from restrictive to free flowing then something is wrong...

 

^ now youre on the right track......


everyone agree ? disagree?

 

You should not boost less when opening the exhaust. Something must be leaking in your turbo control system, causing you to lose boost.

Maybe the wastegate doesn't hold?

 

Going to a freer-flowing exhaust will always tend to increase boost, not decrease it.

 

So what type of exhaust did you change to anyway, a more restrictive one or a more free flowing?

 

well your answers are kinda what i was afraid of! lol


i removed my stock cat-back in favor of RB dual tip, version 1. it sounds great! quieter than stock!, and feels a little faster....but that quiter than stock part probably explains my little question.



see, the trick is, my OEM cat-back muffler was so rusted through,top and bottom, the only thing i can come up with, is that it actually flowed better than the RB@! which is probably why its also quieter. The stock one sounded like a jet taking off by the time you got into the secondary.......wooooooOOOOOOSSSSSHHH! SERIOUS airflow noise from the rear....it was actually quite cool! lol.



so given my BC reaction and what you guys have concluded.....i may have made my car slightly slower with an aftermarket exhaust! haha