GReddy Profec B Questions

[JDMMA70]

Ok so i was reading the manual for the Profec B and i have it set up correctly.

The car has GReddy TD06H-20G Turbo, Tanabe SHM, GReddy Type S BOV. Thats it for mods.

When i went out to tune the boost, even on the min setting it would still boost past 8psi.

Heres how its set up (I did not set up the Boost Controller it was on the car when i bought it)

For the pins on the back. 4 is up, 3 is down, 2 is up, 1 is down

The hose im holding in this picture is going to the IN inlet on the solenoid box. The OUT inlet is going to the wastegate.

Should this boost controller be able to turn the boost on my turbo down below 8psi?


Thanks
~JDMMA70

 

[Nick M]

Not if the wastegate spring isn't soft enough. Pressure still has to overcome it to open.

 

[JDMMA70]

Not if the wastegate spring isn't soft enough. Pressure still has to overcome it to open.

So im pretty much stuck with this problem until i upgrade the fuel system to raise fuel cut?

 

[Facime]

So im pretty much stuck with this problem until i upgrade the fuel system to raise fuel cut?

This statement confuses me.

but as Nick said, you cannot boost LESS than the spring allows. Boost controllers essentially bleed off pressure to keep the gate closed longer, but cannot "amplify" pressure to open the gate early.

you are still hitting fuel cut at stock boost levels? You still have a problem somewhere that a boost controller is not going to fix.

 

[JDMMA70]

This statement confuses me.

but as Nick said, you cannot boost LESS than the spring allows. Boost controllers essentially bleed off pressure to keep the gate closed longer, but cannot "amplify" pressure to open the gate early.

you are still hitting fuel cut at stock boost levels? You still have a problem somewhere that a boost controller is not going to fix.

No it boost past 8psi. I meant am i going to have to live with this as i can get it to hold boost steadily at around at least 10psi or even 12psi. So i said will i have to live with this until i upgrade my injectors, fuel pump, and go to a lex afm?

 

[Facime]

Should this boost controller be able to turn the boost on my turbo down below 8psi?

I was answering this question.

I have no idea exactly what else you are asking I guess. Are you asking.. is 10-12psi max boost on a stock system without a/f upgrades? yeah pretty much.

 

[JDMMA70]

I was answering this question.

I have no idea exactly what else you are asking I guess. Are you asking.. is 10-12psi max boost on a stock system without a/f upgrades? yeah pretty much.

In short. Since i cant get it to hold bost below fuel cut ill have to deal with this. So you answered my question. Thanks

 

[Facime]

so you are saying that you spike to 10-12 with no intevention at all? That tells me you have a problem somewhere. Shimmed gate? pressure leak on your boost reference lines? the stock gate should be 6-8 at most. You could try bypassing the boost controller (just run a line from the turbo outlet to the gate only).

You want to be able to NOT hit fuel cut while at non-manipulated levels. Then you can start turning up the controller until you top out, then back it down a smidge. At least thats the general idea.

 

[JDMMA70]

so you are saying that you spike to 10-12 with no intevention at all? That tells me you have a problem somewhere. Shimmed gate? pressure leak on your boost reference lines? the stock gate should be 6-8 at most. You could try bypassing the boost controller (just run a line from the turbo outlet to the gate only).

You want to be able to NOT hit fuel cut while at non-manipulated levels. Then you can start turning up the controller until you top out, then back it down a smidge. At least thats the general idea.

Ill check the vacuum lines for the boost controller in the morning. Ill also check the wastegate. Washers would be behind it right?

 

[Facime]

the washers go between the wastegate actuators mounting bracket and the compressor housing. There are two bolts.