Im trying to set up my car for 400whp using an Fp Green. I currently have a UR turboback but with the stock o2 housing. I was curious if this may be a limiting factor in achieving my 400whp goal.

 

yes it does restrict a little, if you swaping the turbo you might as well do the o2 housing too.

 

Dyno-proven gains on the stock turbo even:

https://www.evolutionm.net/forums/se...no-charts.html

 

I made 480 on the stock o2 housing. soon to be well over 500 whp on e85 fp red combo. The housing restriction is so short and so close to the turbo that the losses are not as big as many make them out to be.

 

we barely made more on stock dump after switching to a Green.

put a bigger/better dump in = more power...

is that 480 at the fly?

 

good to know. looks like the rexpeed is the one i will go with. im trying to be budget minded with this setup.

 

tephra we barely made more on stock dump after switching to a Green.

put a bigger/better dump in = more power...

is that 480 at the fly?
That was at the wheels with mfred from the boards doing the tunning

 

That was at the wheels with mfred from the boards doing the tunning[/quote]

 

It depends on the setup. If you measure the outlet of that thing, it's tiny. I can't remember exactly, but IIRC, it's 2 1/8" diameter.

On 91oct with a Garrett GT3076, going from the stock elbow to the AMS downpipe (with the same catalytic converter) gained ~25whp.

 

I guess i dont see it. Its the same size outlet as the turbo and around 4 or 5 inches long im sure there is some restriction there but 25 whp when its the same size as the outlet to the turbo? I will just say i dont believe it and i havent seen it yet on my car based on comparisons to other cars with simular builds.

 

Mods in my sig. You can easily make 400whp with that setup on the stock o2, I'm on stock turbo with E-85 and made 370whp @ only 26psi

 

It may be about the same size as the turbine wheel outlet, but the outlet dumps into a very large area. Then, it has to squeeze down to the small hole again. If you want to try, run a 6" exhaust all the way to the muffler of your car and put a 2 1/8" hole at the end.

On the Evo 8/9, just swapping out the O2 housing to a better design would gain 10-15whp.

That ~25whp gain was also on a bigger than stock turbo and also on 91 oct. You probably won't see the same gain on 93 oct.

 

In the evo 8 and 9 the o2 housing is seperated and a completly different setup than a evox

 

My road dyno calculator. On our final runs, we actually made 490 whp using a DJ correction (calibrated against English Racing's dyno). His Evo is a bit of a freak because of the highly ported head. Power kept climbling beyond 8000 rpm. Only 24.5 psi of boost at 8000 rpm on WA 92 octane gas.

I remember the early days of the Evo 10 when AMS was saying that there was nothing to gain by going to a larger O2 housing. IIRC, the issue is that the turbo has a very long extension from the turbine out let to the O2 flange, and its relatively small diameter, so there is a bunch of flow restriction there, and beefing up the O2 housing has a minimal relative effect. I imagine that there is something to be gained with going to a better housing, but its not going to be a 30+ whp difference. Its likely no better than the Evo 8/9 which is usually around a 10-15 whp difference.

 

It may b worth the money to just buy the rexpeed if I can find a place that has one in stock.