Same engine design? Like another boxer or another fa20? 23psi on a gtx28 on pump gas!!?? Wow that turbo is going to be blowing nothing but hot air over 18-19psi. If I was going twin scroll I would've done a gtx3071 at a minimum, that's why u go twin scroll is so u can use a larger turbo but not lose spool. Having a lower compression engine allows for more air from a larger turbo. I think that the little 28 just doesn't have the lungs to feed the demands of a built lower compression fa20. Mine hit 360whp on 91 pump at 16psi

@Dipstik Not another boxer but another FA20
@all It seems that a GTX2867R is simply not capable of reaching its hp rating on pump gas. A bigger turbo seems to be a better choice.

If you factor in 17% drivetrain loss you're at 430ish whp so that's not bad considering.

Unfortunately, I believe it's the other way round. The dyno numbers I got (350-370hp) have already factored in the drivetrain loss. This is what OEM car manufactures and European tuners do. In other words, the whp are lower...probably around 300 whp.

I am not sure whether the supposed drivetrain loss is 10, 15, 17 or 20 percent.

So u only made 350 crank !!???? How is that even possible?

can you post the dyno sheets?

Sounds like @Synack s car

I do not have dyno sheets right now. Tuning is still work in process and I got only preliminary results so far. But I will post follow-up info asap.

Something is not right, I'm making 303whp at 10.5psi with a ebcs, 2.5 exhaust. gt3076 front mount/FMIC el headers. stock internals, injectors and fuel pimp. I am AT as well

He's lower compression. That requires more airflow from an already undersized turbo (when twin scroll)

Yep lowered compression needs more boost to make the same power. Now with lowered compression it's going to be a lot safer, a little more lag, and have higher potential (if you want it).

Update: My tuner found the missing power. Now the car makes approx. 410bhp and 500nm torque. More or less flat torque curve starting from 3300 rpm.

BUT: The OEM AT transmission cannot handle so much torque. Does anyone know about an upgrade? I understand that SSP is developing something?

Thanks.

What was the problem?

I believe the diameter of one of the pipes was too small -> resulting in back pressure and high intake temps.