Want exhaust is recommend for my 91 turbo 940. can you install blow off valves

 

what do you mean "what exhaust?" are you replacing the exhaust for performance? Or just replacing it because it needs to be?

A blow off valve isn't going to do you any good because you already have a compressor bypass valve. there are upgrades for this but honestly, it's a reactive mod...not a proactive one.

 

custom exhaust. a local muffler shop.

thelostartof sells kts for about $550+shipping on turbobricks.com

 

Volvos don't get much performance from exhaust mods, maybe 10 hp max if you mess with the cat. If you want to go with a stock exhaust, go with bosal from rock auto. Cheapest place you can get. Don't go with stuff on ebay and the like. They rust out over one winter.

 

i just want a little extra rumble nothing major

 

what about dual exhaust will that work this is my first turbo car so im unsure on some things

 

check out my car yet?

full 3" exhaust. sounds pretty good, and made a big difference.

 

That's incorrect for a Turbo Volvo. A simple 2.5" cat back system with a good, free flowing muffler is worth 2 psi boost. That's more than 10hp.

Hasn't OP asked a similar question in another thread?

Regards, Andrew.

 

so What size outlet and inlet do i need What size is stock exhaust pipe

 

like Andrew said, a good 2.5'' exhaust will be good.
the stock diameter is a 2.5'' downpipe to i believe a 2.25'' cat back.

i've got a 3'' turboback exhaust.

 

I'm not 100% sure, but the stock downpipe might be 2.25", the stock cat is certainly a restriction, the inlet and outlet are necked down to perhaps 2.25". I know they cut the outlet off my cat to fit my 2.5" system, just welded onto the back of the cat, I didn't want to pay their price for a "high flow" cat, when I can get a good OEM 3" cat for bugger all off a locally built car (think 4 litre turbo six).
Even if the cat wasn't old and full of crud, it'd be a power restrictor just due to this, but restricting the outlet keeps the cat nice and hot for emissions....
2.5 or 3" work well on the street, but 3" definitely needs a good choice in muffler to reduce or eliminate nasty droning, which turbo four bangers are very prone to.

Regards, Andrew.

 

My stock downpipe was 2.5".
I measured it before the new exhaust went on.

 

Cool, I wasn't 100% sure. Glad I know now, I'll leave it alone and just change the cat!

Regards, Andrew.

 

Yep. It is the same size as what Brent did for the transition on the new downpipe:



2.5" to 3" transition.


Here you can see the old system. after the cat it drops, if i remember correctly, from a 2.5" to 2.25"



hope that helps.