Yes they are **** as claimed by 99% of people but I would like to know if anyone have pushed it to its limit (car stopped making power at xxHp xxTq because it hit its max restriction point)?

I'm currently running these on my single slammer F22B1

-Treadstone Cast Manifold



-T3/T4 50Trim 0.63A/R Turbonetics
-2.5" Turbo back exhaust all the way through. Note how the ext wastegate plumbed back RIGHT AFTER Turbine section (Large turbulence in flow?).



-Hondata s300
-Good tune


Problem is that it stopped making power at 290whp @ 6000rpm with current and previous smaller A/R turbo at 15psi (doesn't make more power even is boost is turned up) so I'm investigating that restrictions occurs in the exhaust area. Next project is to get a screamer pipe in which will free up some flow in the exhaust BUT this will only be as good as the restriction before it (the manifold).

Wonder if it is worth it to try if it can hit 350whp by freeing some flow through the screamer pipe?

I'll see if I can dig some some other pics tomorrow.

Cheers.

 

No. they aren't "****". what's holding you back is your downpipe and exhaust. You're building too much restrictive backpressure. open at least the exhaust up to 3", and you could easily gain much more power. Also, the F22b1 cylinder head wasn't the best, so just understand that..

 

Did the calc, by having an 1.5" open screamer it will increase the exhaust area to nearly 3" which would help only at WOT. I just had a thought the manifold is the one to blame since it does look too promising. How does people with unopened F22B1 hit 400whp+?? seemed a bit outrageous.

 

Well, the 50 trim turbos themselves are good to about 420whp as a maximum output anyway. There are still a few people use E-cutouts, but many of us have found that it is best as a full 3" exhaust, unless going to a drag strip.