3 inch downpipe.

[boostnhard]

Hey guys i have boostcreep with an evolll(ported) and stock down pipe.iknow i know, so i ordered a new (evolll o2 housing) but a very reliable source told me that my 3 inch down is still gonna make me creep.he told me to get a 2.5inch donw pipe.

what do u guys think?

 

[DRated]

I think that if you get the EVO III o2 housing and ported, it still won't equal that to a 3" o2 housing with a 3" downpipe. I guess the person that told you to get the 2.5" downpipe was partially correct because the flow of the exhaust won't bottle up where the o2 housing and downpipe connect. It'll just got straight through.

 

[GVR4592]

I think if the turbo was ported properly in the first place you wouldn't have any boost creep issues. Check out the VFAQ on porting.

 

[pooker]

Porting the internal wastegate to 34mm is supposed to help with boost creep if not all but elimate it.

 

[Xeiros]

I think that if you get the EVO III o2 housing and ported, it still won't equal that to a 3" o2 housing with a 3" downpipe. I guess the person that told you to get the 2.5" downpipe was partially correct because the flow of the exhaust won't bottle up where the o2 housing and downpipe connect. It'll just got straight through.

It shouldn't bottle up if he's got a 3" vs a 2.5" It's bigger. Bigger generally means less bottleneck. If anything, it should flow smoother because there's less restriction there.

 

[boostnhard]

I think if the turbo was ported properly in the first place you wouldn't have any boost creep issues. Check out the VFAQ on porting.

even with the stock o2 housing?

 

[delta448]

even with the stock o2 housing?

Decreasing resistance after the turbo will make creep worse. Decreasing resistance in the wastegate passage will make it better. Port it.

 

[DRated]

It shouldn't bottle up if he's got a 3" vs a 2.5" It's bigger. Bigger generally means less bottleneck. If anything, it should flow smoother because there's less restriction there.

So you're saying that if I have a pipe that 3" and I attach another pipe, which is 2.5", to it... it won't be more restrictive?

Which o2 housing would be the best for him to get (that would be the less restrictive with a 3" downpipe)? EVO III ported or...?