Overboosting by adding a 3" exhaust?

[Smoothinto2nd]

I've started parting together the mods I plan on putting on my car and the first piece I was able to find was a 3" catless TBE. I was planning on just throwing it on but when I went to go pick up the 3" gaskets at a local tuning shop one of the guys warned me that adding the exhaust without engine management would cause the car to overboost and "break stuff."

This is the first turbo charged car I've had so I'm unfamiliar with some of the characteristics of what some modifications do and how other things react to it. Can someone explain what "stuff" I might end up breaking and why?

Cheers!

[gijonas]

Sounds like this shop might be in the business of selling engine management?.I assume they must be referring to the small additional boot creep that may take place due to the additional exhaust flow out the turbine,but no your not going to break anything by putting a bigger exhaust on.

[Smoothinto2nd]

ah ok... so other than attention from the man I shouldn't have anything to worry about?

[93forestpearl]

Bad boost creep is common on STi's that have a stock VF39. I haven't seen decent exhaust become an issue on these older cars. The motor is smaller, and the heads and intake keep the flow down, so you shouldn't have an issue.

[Smoothinto2nd]

Bad boost creep is common on STi's that have a stock VF39. I haven't seen decent exhaust become an issue on these older cars. The motor is smaller, and the heads and intake keep the flow down, so you shouldn't have an issue.

Ok that would make sense then why this shop gave the warning. It was a Subaru tuner who had a shop full of newer cars.

I don't plan on going to crazy with my car. My plan is just tbe, intake, wrx intercooler, then a mbc and maybe go up from there.

[93forestpearl]

Yeah, no boost creep issues for you. I'm guessing the shop owners have not seen 22T heads off the car before.