Ok, with no boost controler installed, but simply a vacuum line running from the wastegate to the turbo, I see around a max of 12 psi. (12.5 according to the dyno.) With the boost controler hooked up but not turned ON, I see around 14-15psi. Does anyone else's Profec B do this to them?

Ralph of Groundzero and I have played with this thing a couple times....and tried a couple different switchs/vacuum line setups. But the only problem is that it won't just let me run 12ish psi. Wich I would like for running around town and stuff. Anyways, I was planning on getting a new boost controler, but was thinking if I can avoid it, that would be great but if not, it was no big deal. Thanks, CJ

 

have you tuned it, you have to turn down some of the gains to get it to stock boost levels. My profec Brand new raised boost by 2psi and made it come on 100 rpm earlier. your setting seem to be about similar. Have you changed the settings to get what you want?

 

I've turned down the high and low boost as far as it goes. Its still 2+ more psi than the wastegate spring. So it sounds like your profec does the same thing as mine...is that correct? CJ

 

no that is not correct, Mine factory setting made 2psi more than the spring, but when I adjusted the settings, it works like a charm it runs 10.4 psi boost (spring) but it comes on a full 350 RPM faster than just the wastegate spring.
Which profec?
I have Profec B SPEC II

 

I just have the profec B. Maybe I have a bum one from the factory. Thanks for the reply. Anyone else? CJ

 

Tell us how you hooked up the vacuum hoses so we can help verify the installation. Any boost controller should fall back to spring pressure when it is off -- it should leave the signal to the wastegate side port unmolested and leave the wastegate top port vented to atmosphere.

-Max

 

From my IC pipe right after the turbo, I have a vacuum line going to the IN position on the boost controler box. (Stepper motor?) From the OUT nipple it goes down to the side nipple on the wastegate. My little switchs are 1 on, 2 off, 3 off, 4 on. This is over boost mode according to the crappy manual.

The car is'nt at my place right now...but tomorow, I'm going to see if I can blow through the stepper motor box thingy with it unhooked and no power. I'll tell you guys what I find. CJ

 

If you have an external wastegate (and I assume you do), use both ports and hook it up according to the instructions:
http://greddy.com/tech/PROFEC_A_B_HELP.pdf

I bet that will fix the problem.

-Max

 

I'll try hooking it up like that again. I'll post what I find out or break. last time on the dyno, we hooked it up the external way, and ran 22psi! Kinda hard on a motor with 50k miles on it. O well. CJ

 

Make sure the switches are right, etc -- the Profec has to know that it should decrease the duty cycle to decrease the boost in that configuration. The way it is set up currently, it needs to increase duty cycle to decrease the boost.

I have seen another car with an external wastegate that was setup the way you were running it. It is uncommon to do it that way with an external wastegate, though.

-Max

 

That's incorrect (or your description is)! The way you've described it, you're interrupting the signal to open the gate via the Profec. And where's the line to the top of the gate?

This is the correct method:
Comp housing or intake manifold (pressure source) -> solenoid in
solenoid out -> top of wastegate
Comp housing or intake manifold (pressure source) -> side of wastegate

There are advantages and disadvantages to using compressor outlet vs. intake manifold for pressure source. Try the recommendation in the Profec manual first. Then fine tune. With a 35R, TiAl gate and Profec B I use compressor outlet for both pressure sources.

Gene

 

and what dip switch settings are you using? same as stock twins? (internal wastegate)

 

Well I finally had a chance to drive the car today. After alot of tweaking, and routing and rerouting hoses, the car holds around 12psi of boost. Thanks everyone for your help. CJ

 

ahem ^

 

Use the settings for external. Switch to overboost if that's an issue. I'm not encountering overboost issues with my car.

Gene