it almost looks like an exhaust restriction.

 

how can we trouble shoot that? i know im running 3in from the down pipe back

 

the tuner told me he was doin a conservative tune since i still have my OEM clutch, he said the AFR at WOT is 11.5 he said he added 2%more fuel to keep it running rich

 

yea i noticed that as well its like it peaks at 6500rpm and stays flat till redline ...whats up with that? i still have stock clutch though ...slippage?? im no tuner at all so i dont know

 

 

not really.......... not at 11psi, he is going to need more boost to get to 400 WHP with the 3mm gasket and that turbo

 

i plan on goin 15-16psi when i install my new clutch im just waitin till the OEM one gives up. BUT... these numbers should still be a lil higher

 

Now Im new to the whole turbo thing as far as the S2k goes but I did have a turbo miata for 5 years so I know about FI and how it works. From what I have read an s2k w/ a Log manifold ( assuming you are using the p-fab log ) with a GT3076R should yield you about 13-15whp per pound of boost. Lets just say that you were making 200whp prior to the turbo. Adding the turbo assuming a good tune and a free flowing exhaust ( which you have ) you should make 150-165whp EXTRA. That would put you at 350-365whp and that seems to be in line with what most other F20 or F22 engines are making.

Its possible that you might have a leak somewhere in your charge pipes, or maybe the P-FAB log manifold is THAT restrictive. The Inline Pro manifold generally will give you 13-15whp per pound of boost and I would assume that the P-FAB manifold would be similar but maybe its just horrible for flow. Right now you are getting less than 10whp per pound of boost and with a Gt3076 and an engine that flows as well as the F series engine their has to be something wrong. Good luck buddy.

 

im using P-FAB tubular manifold. how can i detect a where a restriction can be or if there were to be a leak somewhere

 

well thats even worse because tubulars usually will net you 18-22whp per pound. There has to be something wrong after 6500 because like others have said your torque drops off way too fast. Are you dropping boost after 6500 rpm? I would just check all your IC pipes to make sure there are no leaks anywhere. Is it possible that vtec isnt engaging because with power dropping so fast after 6500 it would make sense.