I'am running straight through exhaust on my car but stock air box and k&N. If you don't change the intake and boost never goes past 12 psi then you are fine. I never been past 11 psi. The stock main cat piping is 2.5" and acts as a restricter from the rest of the 3" piping from the DP and cat back. The stock air box is really restrictive and once you add that on, you had better have an ECU upgrade.

 

double post.

 

triple post.

 

If he's really breaking in a new engine, I would also assume (and hope) that he's not going to be doing a bunch of wide open throttle runs. I don't think there'll be an issue during break-in, if my assumptions are correct.

For the original poster, I think he'll be OK too, IF he can keep the boost at 10psi or less. That will be the problem of course. Even with the stock cat, catback and downpipe, I see spikes at the transition of up to 15 psi if I go all out. Eek.

jds

 

That's probably a good rule to tell people to scare them away from doing anything crazy until they've learned something about the cars, but I don't believe there is any sound evidence to show that its true. Depending on those mods, IF you can keep your boost in check, you'll be fine...you're not going to increase flow to such an extent that the stock ECU can't keep up...at least until you do something like put on a midpipe. But in that case, its highly unlikely that your boost will be in check anyway.

Of course, this is all just my opinion, I could be wrong...but I'd like to see some actual evidence of that (like AFRs) rather than just anecdotal "My friend blew his motor with a catback" stuff.

jds

 

With a downpipe and midpipe, all bets are off with boost control. I don't think the stock airbox is so restrictive as the exhaust. I've seen and heard too many people having boost spikes with a midpipe.

Skunks, what the hell are you doing for boost control? You have more ***** than I, buddy.

 

Dude, don't listen to these *******! You'll be fine, believe me, I have had two FD's and as long as you don't boost heavily everything will be straight! Don't always believe the bull **** that you hear on this forum, because 50% of it is just a myth! I'm not saying that this forum isn't helpful because this is where I learned almost everything I know about rotarys, but I'm just saying get ready to hear some BS!! Just break the motor in, get it tuned when you can and then have fun!

 

i've upped the boost to 10 psi and noticed a gain in power and i aso had no problem maintaining it to 10 psi with the stock ecu, though i would like to use my bought AEM ecu so i can boost some more