Loss Of Power Above 6000 Rpm

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hi id like an opinion from the experts, here'e my problem.

I own a 1996 series 2 skyline with forged pistons, methanol injection, custom plenum, gtr fuel pump, garrett gt3076r on custom manifold, aem fic, stock injectors , external wastegate set to 10psi.

about two months ago i came across a "swat" ecu from an r32 gtr and decided to give it a try.

members on the forum advised me of the necessary conversion to make the ecu work ( add additional o2, additional maf, air temp sensor, disconnect vct.), the car ran fine after adjusting the cold start, 12psi by about 3200rpm and with the motor reving to 8500rpm i have about 5000rpm of boost.

the car feels great on the street, but i went to the local tracks here in Nassau Bahamas and my best time after 5 runs was a 9.4 in the 1/8 mile on 10psi. With my stock ecu I run a consistant 9.1 with the same psi. I race on maxis va 1 street tires nothing special so i expect alot of wheel spin. I think however with the more agressive time curve in the "swat" ecu I should have lowered my elapsed time.

the car has alot of power down low, so i started to attribute the lower ET to wheel spin, but whilse racing a stock series one skyline on 14psi ( stock ecu, stock turbo) i noticed he was able to pull away from in third gear. after abit of seat time today, i realized the car looses power above 6000rpm, any opinions on what could contribute to the loss in power. the afr are consistantly around 12.2 and the boost is holding so i dont believe its a leak problem, the only thing off is the power.

any ideas

[Tangles]

got access to a dyno?

if so, try installing an additonal piggyback Safc unit to adjust the tune

[tridentt150v]

Not a lot to go on, but with that set up you'd have to be looking at mid 200's rwkw [250], I'd question std injectors, but as Tangles says, you need a dyno to sort it out.

[Sheriff Wan]

I'd be looking at the ECU... sounds like you haven't had it tuned to your mods so its not going to respond very well...

Get it on a dyno and tuned, AFR's are one thing - timing etc etc is a whole nother ball game...