optimal pressure

[Tames]

Hello, I just bought a 1989 Supra turbo 7MGTE engine, one of my brother gave me a Turbo XS valve to variate the turbo PSI´s everything in the engine is stock, now the turbo is loading 6psi I would like to know what would be the optimal pressure to have good power but keeping the engine safe from blowing, thanks in advance.

 

[bioskyline]

8psi is safe, but if the headgasket hasnt been replaced and torrqued right, i cant gaurantee it will hold. im running 8psi with a retorqued oem gasket and works fine. any higher and you may end up hitting fuel cut.

 

[hvyman]

Get a full dp and intake and intercooler and the boost should raise it self. Then take it to below fuel cut.

And yes if the hg is on its way out its going to go quick with added boost.

 

[Tames]

dp?

 

[hvyman]

Downpipe

 

[Compton74]

if you still would like more boost after the intake, dp, and intercooler and pipes, you can get a lexus AFM and 550 injectors which will raise your fuel cut. I run 550s and a lexus AFM with a 57 trim ct26 and a STOCK headgasket torqued correctly, at 15lbs all day long. The car is reliable and fun. Be careful and have fun!

 

[honeydew]

Oh God no. Guys give the guy some practical advice. He JUST got the car.

Raising the boost over 8PSI is asking for trouble. If I were you (which I was) I'd enjoy the 6 PSI and the loose rear end for a while.

Of course this is unless you want to wait and pay for a head gasket job along with milling, head bolts, gaskets, etc. Cripes. The HG will let go, no question.

 

[hvyman]

^not really. Turbo 5speed supposed to be 7psi and auto 5-6psi. 1-2psi is not going to hurt unless a problem is already there.

 

[honeydew]

^The problem is already there, 22 year old head gasket *suddenly* getting extra boost.

 

[mecevans]

Leave the boost controller off until you do all preventive maintenance.

 

[IJ.]

 

[digihonk82]

If it's your DD I wouldn't recommend driving it how you want, but if you do and it blows up, you get a crash course on being cool Supra hardass like me.

 

[STREET90]

hmm how much more boost would I get with stock setup if I got 2.5 intercooler piping, a 31x11.5x3 inch intercooler, 3" aluminum intake and 3" exhaust all the way from the turbo no cats. sorry for stealing just curious

 

[Tames]

Thanks everyone for the good advises, I will do eerything but in steps, first: preventie maintenance, then slight mods like inter cooler, dp, and variable valve, afterwards the AFM and the rest.

 

[hvyman]

^The problem is already there, 22 year old head gasket *suddenly* getting extra boost.

99.9 cars out of 100 are not on stock hg....