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Jwt Ecu Q

690 Views 6 Replies 5 Participants Last post by  FastNX
My current ecu is 3bar, S4's, 370's, 9.5:1 cr, stock maf, rear O2 sensor delete, egr removal. This was programmed for my 95 se-r lp engine-which is dead. I am going to use an Avenir motor. What I want to know is will there be any drivability problems with this ECU and an Avenir motor without the S4's? You know ECU is 9.5:1, engine is 8.5:1. I don't want to send the ecu back to JWT to change just the cr setting. thanks
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If compression ratio is accounted for when JWT works on the ECU, I'm sure it does matter if you put an ECU programmed for 9.5:1 to a 8.5:1 motor.

I would guess that they use a little more ignition advance in the lower compression motor than they do on the 9.5 motor. It shouldn't hurt your motor at all.
i had the same question. i called JWT and they said the ecu will work but the timing maps are more conservative with the 9.5:1 program. i asked if more base timing would correct this and he advised not to do that because the timing is not a linear curve thru the rpm range, so may have too much timing at certain rpms'. i haven't got mine running yet so thats all i know.
If I send the ecu back for reprogramming, I want to make it worth the $100. Would going to a Z32 maf, 4bar 370's be worth while on the stock T25? I may swap to a T28 a few months down the road. Just trying to think ahead. I know anything above 12psi will kill the T25 quickly.
Anyone else?
I'd go for the bored MAF instead of the 300ZX, IIRC the Z32 MAF can read up to about 500hp so you'd lose too much resolution. The bored MAF is probably in the range of 0-300hp
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