I was running the G25-660 0.72 and I think the G25 is too small for the high revving F22. Running the 0.72 ar there were little gains after 18 psi. We took it to 25 psi and boost drops, past 6000 rpm and was pumping heat. I'm running a log manifold, Mahle 9.5 CR pistons, e85, Infinity, ID1300, stock head. Response is awesome and great little turbo for getting around. Full boost around 4400 rpm but little to no gain from 6000 to 8600.
Since, I've changed to the 0.92 housing. Response feels similar but have not been to the dyno yet.





I need to change my signature. It's old.

 

You definitely need a big hot side for the F motors. I went with a .92 on my EFR and I never feel choked up for the power I've run (up to 400whp). This is the very reason I did not go with the B1 framed, EFR 7163 and went to the B2 frame and a 7064.

 

What manifold is that? Looks like a log design? (edit: I see you said it is a log, duh). Anyway, I'd recommend a G30-660 with 0.83 A/R over the G25-660 in any A/R. I got my turbo about 4 years ago, before the G30-660 was released. Otherwise, I would have gone G30-660 in 0.83 A/R without hesitation. I think it will only spool ~200-300rpm slower than the G25-660 in 0.72 A/R, but free up the top-end quite a bit. More turbine flow and better turbine efficiency due to a better compressor to turbine size matching, so significantly more power with little impact on spool. I think the G30-660 in 0.83 A/R could actually spool as fast or quicker than the G25-660 in 0.92 A/R and make ~25-30whp more.

Also, I fixed my intercooler coolant flow issue and got back on the dyno. Intake Air Temps stay nice and consistent now and within ~15-25F of ambient. Air temp was ~72F, IAT started at 83F and finished at 97F during the 4th gear dyno pull which lasted a bit over 13 seconds at full-throttle. Boost peaked at 15.0psi at peak torque and was down to 14.0psi at 8500rpm. On spool-up, boost solenoid duty cycle was at 30%, so there's room for improvement there to quicken up the spool-up.

 

I forgot about this test Speed Academy did on a STI with EJ207 motor bumped up to 2.1L. G25-660 w/ 0.92 A/R vs G30-660 w/ 1.01 A/R. Same compressor of course, 100whp gain on the top-end on ~102 octane fuel. There was a big increase in lag on this particular setup. Personally, I would have gone with the 0.83 A/R like I mentioned before

 

needs a larger hot side for the F motor and a log manifold does you no favors. flow some more air to make use of it