I had the DC sports catless downpipe, and a stock o2 housing, and I changed up to the MAP Performance o2 housing dump / downpipe. I never did a before and after dyno, so other than my inaccurate butt dyno, I don't have much to go on. We do notice that my boost does not taper much up top. It falls from 22 to around 20 or so at 7k.

Does anyone have any experience with this downpipe, to say for certain that it actually makes power over other downpipes?

Basically, I want to know from the big power makers (ams, buscher, whoever makes good numbers), what downpipe/o2 housing combo do you think woudl make the best power with a stock 8 or 9 turbo, with a lot of boost? In theory, the open dump should flow really well, but I want to know if anyone has comparisons to prove it.

Thanks guys!

--mark