Profec B Question

[Dan5624]

First of all hello, have just found this site.

I have a Celica GT4 ST205 Jap spec and have been slowly modding it up, my latest addon is a Greddy Profec B Spec2 controller which is getting me a little confused.

Other mods include:

3' S/S system from turbo back inc decat

Blitz BOV

Samco Hoses

HKS Panel Filter

Tarox discs

For some reason even with the boost controller running standard settings i am hitting 17psi which i cannot understand. When i change gear it seems to run a lil higher if that makes sense? So im driving reading say 15 psi then when i change gear it creeps upto 15.7 for example.

I read on a site that the standard turbos don't really like more than 17 psi and the fuel cut is around 17-20 psi but i cannot understand why we would be running 17 psi with only a decat and a filter!

Am kinda feeling the boost controller was a waste of money as if it is reading correct and it is running 17 psi i cannot up the boost anyways.

We turned the last boost feature on and the readings were slightly higher than my other gauge so i am still not 100% sure what boost it is actually running. We did get a little boost spike where it tailed off from say 17 to 15 psi and tried to turn the start boost up a little to compensate but still tailed off a little.

Do any of you guys have experience with these Profec B's?

We did up the boost around 3.5 psi and it read 20 psi on my gauge!! It did go like stink then the fuel defender cut in and spoiled the party.

I have turned all the settings back to standard for now until someone can help me out.

Sorry for the long first post!

[damo746]

First of all hello, have just found this site.

I have a Celica GT4 ST205 Jap spec and have been slowly modding it up, my latest addon is a Greddy Profec B Spec2 controller which is getting me a little confused.

Other mods include:

3' S/S system from turbo back inc decat

Blitz BOV

Samco Hoses

HKS Panel Filter

Tarox discs

For some reason even with the boost controller running standard settings i am hitting 17psi which i cannot understand. When i change gear it seems to run a lil higher if that makes sense? So im driving reading say 15 psi then when i change gear it creeps upto 15.7 for example.

I read on a site that the standard turbos don't really like more than 17 psi and the fuel cut is around 17-20 psi but i cannot understand why we would be running 17 psi with only a decat and a filter!

Am kinda feeling the boost controller was a waste of money as if it is reading correct and it is running 17 psi i cannot up the boost anyways.

We turned the last boost feature on and the readings were slightly higher than my other gauge so i am still not 100% sure what boost it is actually running. We did get a little boost spike where it tailed off from say 17 to 15 psi and tried to turn the start boost up a little to compensate but still tailed off a little.

Do any of you guys have experience with these Profec B's?

We did up the boost around 3.5 psi and it read 20 psi on my gauge!! It did go like stink then the fuel defender cut in and spoiled the party.

I have turned all the settings back to standard for now until someone can help me out.

Sorry for the long first post!

Is this happening in all gears? Because if it is only happening in 3rd, 4th, and 5th then it is the tvsv system that will be responsible. The tvsv system allows the turbo to run 2 more psi in the higher gears, I had problems with it when I was setting my Profec b up its easily disconnected go on to the gt4 owners club website and search tvsv you'll get all the information you need. Hope this helps.

[Dan5624]

Thanks for the reply, yes i believe it is only happening in the later gears as this is when we are giving it a bit of juice to see what boost it's running.

I will have a read up on the tvsv system and see if that helps.

So with your Celica what did you eventually turn the boost up to?

Thanks again.

[GTForbes]

you need to dissconnect the TVIS, easily done, on the standard actuator there are two hoses, the one that runs to the rear of the engine needs cut and blocked, best to do that on both sides.

then try setting up the boost controller, if you have no joy and are just gonna chuck it send it this way ;) :P