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hi all, i just went to get a quote for installing a frount mount on my '94 GTS25t, and the guy at the shop told me that if i wanted to up the boost to around 12psi i would have to most likely get a new computer as the stock ones dont handle the boost to well... especially once they hit 5000rpm apparently the car acts as if it hits a brock wall... and goes all wacko?? .... anyone know or heard about this... and would it be safe to up the boost 2 12psi without a new computer???

- regards JT

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Yes its true.

Upping the boost with standard management takes the ecu into a rich and retarted area of the fuel and ignition maps.

You basically, just get flats spots if you increase boost with standard management.

With an aftermarket ecu you can up the boost and tune the entire map to pick up more response and power throughout the entire rev range then compared to the factory ecu.

Most people here would agree that the PowerFC that can be purchased sub 1K delivered from Japan, would be best value and offer the most factory type reliability and drivability.

Wolf 3D also do plug in ECU for the Skyline at $1395 with hand controller.

It comes down to what the tuner can tune best.

You don't need to run 12 psi... get a bleed valve or electronic boost controller and run around 11 psi and you won't hit rich and retard...

if you want a cheap way to lean out your air fuel ratios get an Apexi AFC...

I have an EBC and SAFC and am running about 10.5psi no problems...

no point running more through the stock turbo as you won't see that much more power...

yeh i wasnt exactly speficing to up the boost to 12 psi... i just mentioned to him i wanted hi and low... and he pretty much said yeh high no good with stock ecu.... so nick u reckon running round 10psi would have no worries with stock ecu yeh?

I don't have any problems at all... and my friend has his at 13psi and doesn't have any issues either... there are alot of reasons why people have flat spots, missfires etc and only some of the time is it to do with the stock ecu's overboost protection...

what I am trying to say is that if you already have tired coils or worn plugs or some other undiagnosed problem, upping the boost may expose the problem but is not always the cause of the problem... make sense?

Yer all sounds true from what i have heard you don't really want to go much past 10psi with the standard turbo's anyway, don't forget they are 11 years old unless they have been replaced so they have properly already had a far bit of punishment but i would recommend the the fmic you will be able to turn the boost up a little and it will be safer with the intercooler. I am running wolf 3D i thing it is great all depends were you want to tune you car and what they use my tuner was better at wolf so thats what i went for

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