st wastegate actuator

[kmac]

So today I did a little wastegate experimenting to see the spring pressure. So I ran it off spring pressure with no solenoid and I was getting 6.5 to 7 psi and it's a single port gate. I think even with cycling thd dc on the solenoid it's going to be hard yo maintain boost upstairs, because it's a bleed type system. So even if u comand a higher dc the exhaust pressure may be to high in the turbine, because it's so small to keep it closed. I will either be designing a new one or going external.

I also found the bov leas for 2 reasons one the spring is too weak as well as when i was chasing down the vac lines i found something interesting. The bov doesn't get its reference from the manifold. It goes to a solenoid that has 2 linez on it one boost one vac from the mechanical pump on the intake cam. So under boost it's suppose to allow the boost to pass through to keep it closed and when it's time to blow off cycle the solenoid close off the boost side and pass through the vac to release. But under boost I herd it fluttering so I bypassed it and went to manifold vac source and it went away. The boost went from 17.8 to 19.5. So that's permanently over rode .

[Haltech]

That solenoid is perhaps an emissions decision most likely. Since BOV's do not recirc, they have to address where this valve vents.

Plenty of aftermarket wastegate controls, so no biggie for you there. It will be an issue for those who just swap the solenoid over if a bolt on replacement ever becomes available.. This is what makes you a Gearhead, addressing the choke points and identifying future problems with solutions.

[kmac]

Originally Posted by Haltech That solenoid is perhaps an emissions decision most likely. Since BOV's do not recirc, they have to address where this valve vents. Plenty of aftermarket wastegate controls, so no biggie for you there. It will be an issue for those who just swap the solenoid over if a bolt on replacement ever becomes available.. This is what makes you a Gearhead, addressing the choke points and identifying future problems with solutions.

I don't think it's emissions, I think it's another way to control boost for modding reasons. The bov does recirculate it's built into the compressor. It blows off boost internally and dumps into the intake on the compressor. I think I'll weld an external on with a 18 psi spring that will fix all. And by the way thank u so much for your compliments and support it means a lot to me.

[Tokay444]

Possible guardian angle built into factory bov?

[Vader]

Originally Posted by Tokay444 Possible guardian angle built into factory bov?

[JRD1]

Check out the Forge WG. I believe they did a bolt on replacement for the stocker... I was talking to some of the guys across the pond and there are a lot of parts that work on our ST from England. The kool thing is a lot of the engineering has been done and most of those guys are pretty free to talk about the car with us and what they have found.