safe boost on a jspec?
 

Im pickin up this 88 Turbo2 with a jspec motor and turbo. He says the car runs at 12 psi. Is this too much boost?.....Here are the mods it has............

88 t2, jspec flash to pass lenses,jspec engine, jspec decals(gtx), mazdatrix short shifter, stainless steel oil lines, apexi dual n1's catback, bonez down pipe,bonez race pipe,bonez intake,AutoMeter Boost Gauge,haltech haltuner, border headlight cover,jacobs rotary master,energy core wires,apexi blow-off valve,enkei rpo2's falken tires,greddy turbo timer,greddy radiator 1.3 bar cap,racing beat under drive pulley, knightsports dual alternator pulley,custom front lip,rotor oil cap,g-force ecu,walbro fuel pump,round tail lights,kyb agx adjustables,intrax springs,removed air pump

A jspec is no different than a American TII engine. They call them jspec's because they come from wrecked cars in japan. The blocks are the same as over here. I am not seeing any fuel mods along with that high flow exhaust, so that could be a problem. You could get some serious boost creep, so keep an eye on that boost gauge, or the engine will pop. Warning:Autometer gauges are not the best, so it will probally be off.

Fuel
 

He's right. I have an 88 with the 89+ jspec motor running 13psi. I have 720's in the secondaries and a greddy front mount. This combo seems to work great. The SAFC comes in handy for fine tuning the fuel curve. Also get yourself a good air fuel meter gauge. I have the autometer one. It works great. As far as my Autometer boost guage......thats another story. It's only accurate sometimes.

for safe everyday driving, 10-11 pounds of boost is perfect.

He does have the walbro fuel pump. My buddy is running the RB turbo back with just a walbro 255 lph HP pump and an S-AFC. Runs like a dream..at WOT and everything. Except on some cold nights, you have to watch for the 15psi spike :eek:

It has the Haltech air/fuel guage but isnt hooked up, the guage goes where the O2 sensor would be so is it ok to run with no O2 sensor?....Im plannin on getting the SAFC from APEXi, is it hard to install and tune?

Thanx alot for the help guys, Ive had 2 N/A's and im jumpin to the dark side with the Turbo II

The S-AFC can be tricky. I haven't ordered mine, but guys around here can help. It will run a little rough w/o a O2 sensor. I am not reallly understanding the location of where the a/f gauge wires into. It should wire to the 2 sensor, not replace it.

Keep it under 14psi; anything over that and you'll be blowing turbos.



-Ted

Umm well, I can't really agree with the blowing turbo's bit, I have seen the stock turbo taken to 1.5 bar repeatedly with no turbo problems, mind you the stock turbo makes no more power at 1.5 bar than it does at .8 bar, so there is no purpose in it.. Ask soloracer how much boost he ran this last summer, the stockwaste gate could not handle the streetport with no afm(wolf 3d installed), his wastegate opened at 7 psi, but boost always ran around 15-21 lbs, he was fortunate to be heavily overfueled, so I think his motor survived, the turbo is A OK at this point. His car was no faster than mine which was running 9-10 lbs, in fact mine may have been quicker, due to better tuning, there is an avatar floating around of black TII with 2 big flames shooting out the exhaust, thats Soloracers 4wheeled welding torch...Max

That's crazy...
I've had mines tuned to about 14psi with no problems.&nbsp Once i tried to tune up to 17psi, it puked it's oil seals.&nbsp Many have experienced similar results.

Your friend is either lucky, or he didn't hold it that long.

My experience has shown that 14psi is absolute limited the stock turbo (with the stock carbon seal in it) can take before the carbon seal will start to disintegrate.



-Ted

He drove it pretty hard on numerous long high speed cruises, yeah I know its crazy, but he has a t04E ready to for the car, so he was not to concerned about blowing the turbo, the motor still runs ok, its had a chronic oil leak since it was originally built so I kinda think he was hoping the motor would just grenade to give him a reason to redo it, but it took it and still runs, amazing eh? Chris Ng and I were looking at his turbo a few times, amazingly his turbo seems to be in better shape than ours and Chris and I were running alot less boost. LOTSA fuel defintely saved the Apex seals though..Max

with the g-force ecu and fuel pump you should be ok.

how do you get 14psi out of the stock turbo?

Boost pressure is exceding what the wastegate can vent, or a boost contoler.

How much you getting the car for? It sounds like it has a nice list of mods (hell, the Haltech is $1500!).

umm read closer.. haltuner is a A/F gauge :) he has a g-force ecu :D

umm....I'll tell you the price when the cars in my driveway, i think im gettin a good deal on it. Again, thanks for the help everybody

O.K. I guess I didn't ask right. So how can I get 14psi out of a stock turbo?

or rather make the turbo push 14psi?

I answered it. Boost contoler

Free flowing exhaust, HI-FLOW intake, boost controller with all that you could get there. Kiss your engine good-bye if you don't upgrade your fuel to compensate all that boost. 9 - 11 psi is good for the stock turbo. I wouldn't run anymore than that unless you've got a backup engine/turbo :D

Re: safe boost on a jspec?
 

Wrong decals, it should be GT-R. ;)

Fix it when you get it.. you dont want to be a ricer do you? =p

yeah i know its a GT-R that but it has the 89+ tail lights.....so im undecided on that one

GT-R and GT-X has nothing to do with years.&nbsp it's different trim levels.&nbsp Both GT-R and GT-X models were available throughout the entire FC3S run in Japan.



-Ted

oh really? What are the differences? Maybe I'll stop calling mine a GT-X.. I thought the GT-R and GT-X refered to the zenki and kouki model changes.. darn.

=p