I recently had a full 3" stainless system put onto my '97...

I am REALLY pleased with the quality of the work, the note on the thing is great - not too loud - really perfect..


EXCEPT!! I am now having some weird boost behaviour... about 15-10-15 in 1st and 2nd (GOES like the hammers!!) , then about 13-5-5 - creeping up to 8 or 9 in 3rd on... I can make it overboost in 3rd if I go WOT under about 4K...

Can I fix this with a boost controller? Or an ECU? Or an external Wastegate?

We've tried restricting the exhaust, and boost goes straight back to normal.. but the car feels crap again - it really loves the exhaust flowing freely...

Really interested in your comments guys...

 

You're probably hitting fuel cut. If you have a stock computer in the car, then you're lucky you don't have low power and rough idle after running that much boost on a stock ecu. Put a manual boost controller on the car, as well as some form of upgraded ecu.

 

Get a boost controller, and upgrade your fuel delivery. If you have a full exhaust..... CB, DP & MP you could really mess things up with out the proper controls.

 

Thanks for the replies guys!

I will probably order a Haltech E11 this week - but is that alone going to do the job?

 

No necessarily. As P'cola FD mentioned, a lot people experience boost creep when using midpipes.

The problem is there isn't enough back pressure and the wastegate can't do anything about it. The only way to solve the problem is to either port your wastegate or add some restriction to the exhaust (restriction plates, hi-flo cat).

However, an ECU upgrade is still a good idea, especially if you plan to keep the car running over stock boost levels.