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Ok, well, last night I threw in the sniffer and pushed my boost from 16psi to 18psi.

Car responded ok once the AFRs were set to 12:1, but I seem to be getting no where rom 6000rpm to 7000rpm (redline.

here are my maps.

http://members.iinet.net.au/~pacey/18psi1.htm

http://members.iinet.net.au/~pacey/18psi2.htm

Wonder why the car isn't really responding to anything above 6k?

Could it be the Ground out RB25 housing on the GT30, or could it be a blocked cat from running stupidly rich maos from the retarded tuner that tuned my car?

I'm thinking of dumping the cat and seeing what happens..

Anyone got any ideas?

Going to dyno the car on this setup, then set it back to 16psi and my other tune. If the power is less than a 5 - 10 rwkw diference I'm gonig to leave it at 16psi...

I had to pull out massive timing on the load row "11571" (thats as far down as the Powerfc goes)

Edited by The Mafia
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my 25 is also the same, power drops off past 6 and never goes higher.

i think its normal and fairly good for the stock cams. i think youll find with bigger cams it wont. bass junky went from stock cams to tomie poncams (i think) and that cured his power drop off problem

I'm thinking of dumping the cat and seeing what happens..

Snip...

I had to pull out massive timing on the load row "11571" (thats as far down as the Powerfc goes)

Having to pull out heaps of timing indicates that you have a backpressure problem.. Check blocked cat, Turbine A/R and all the usuals.

that sounds weird to me though... my car seems to pick up quite a bit from 6000 to 7000rpm... i also have a GT30R... doesnt really die much anywhere, just down low around 2000rpm, thats prob just coz of air fuel ratios down low.... but if others are having the same probs then i guess its a normal thing, jono how much of a difference is there in power loss up top? is it noticable or does it just stop making power after 6000rpm?

i agree with MattSR check out ur cat..

Edited by mass_iv
Having to pull out heaps of timing indicates that you have a backpressure problem.. Check blocked cat, Turbine A/R and all the usuals.

Well, I'm going to do all of that, but the turbine is a Standard Skyline Turbo Turbine ground out to fit the GT30. Do you think that could be too small?

that sounds weird to me though... my car seems to pick up quite a bit from 6000 to 7000rpm... i also have a GT30R... doesnt really die much anywhere, just down low around 2000rpm, thats prob just coz of air fuel ratios down low.... but if others are having the same probs then i guess its a normal thing, jono how much of a difference is there in power loss up top? is it noticable or does it just stop making power after 6000rpm?

i agree with MattSR check out ur cat..

I'd adjust those AFR's down low, you'll be suprised how much of a difference it will make.

As for the power, it doesn't die, it just stops making power after 6000rpm.

I'm going to drop that cat at some stage this week and see what the hell is going on. Might be blocked.

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