Does anyone know what max boost you are getting with the 1st turbo? Also how much boost do you get on 1st and 2nd gear?
Primary turbo consistently hits 11psi regardless of gear (But it will creep higher in high gears on a long full throttle pull). As far as max boost in 1st and 2nd gear, which is what I am assuming you are asking, about 15psi in 1st, and 17-18 (full boost) in 2nd.randy said:Does anyone know what max boost you are getting with the 1st turbo? Also how much boost do you get on 1st and 2nd gear?
I assume you are running the J-spec ceramic turbo's. I would expect your turbo(s) to blow apart at any moment with that level of boost.randy said:Thanks for your response Mike/Ben! The reason I am asking is cause I will be doing the HPF boost mod and this will make my first turbo boost as high as18/19 psi, just wondering how much the first turbo on BPU would boost compared to first turbo HPF mod.
Aprox boost levels with HPF mod according to a friend.
3rd gear 21/22psi.
5th gear 25psi.
6th gear 27psi.
You can see I really have to control the boost with the accelerator. and a boost guage with peak hold warning buzzer.
The general consensus with J-spec car here in the UK is restrict boost to 18psi, I know of people that have lost turbo's within hours of turning the boost up too 18psi and one guy at stock boost levels..randy said:That is the reason I'm hesitating doing the HPF mod! Currently my car feels real fast hitting boost cut on 3 gear at about 5000 RPM. Infact it accelerates so hard the wheels spins even when I am rolling on 2nd gear when it hit the metel. I'm told that boost cut on jap spec is at 16psi. Boy I hit boost cut real hard. Quite shocked the power increase after my custom 2 1/2 front pipe and 3 inch midpipe with no cat. Will check my boost level when I install the 60mm boost gauge and BCC.
I would buy a boost controller, set it too 19psi and leave the HPF mod well alone.randy said:I have been advised by quite a few mkiv nz members who own supra jap spec not to go over 19psi! What do you think my best options are? cause I dont yet have a boost controller and wanted to do the HPF mod. But guess its not worth risking my turbo? Do you think I should buy a boost controller and be done? Is 18/19 psi good enough power?