Barwick

Anyone have any experience with this?

It seems the one on my car (T04E 60-1 turbo) either has a 15 psi spring in it or is creeping at 10 lbs boost (what the previous owner said it was sprung at)...

Any thoughts on this? Is this sucker too small? It suppoedly goes up to 300-400 hp without creep, but I dunno..

btw it's openly vented to the atmosphere (crap it's loud too...)

rxAustin

Not enough "gain" in the system. Try throwing a Grainger valve in there. I used to used a Mallory 3 port return type regulator for the same purpose.

edit:
also make sure your air line to the actuator is not restricted. Most wastegates (Deltagate included) have a pretty decent air leak aroung the actuator shaft, so you have to make sure you're feeding enough air to account for that leak.

Barwick

what do you mean not enough "gain"? There's not enough flow to the wastegate? And with a grainger valve I don't want to raise the boost, I want to keep it to 10 lbs.

madsci

What size line do you have going to the actuator? If it's too small it won't compensate for the shaft seal leakage and will cause response problems.
By "gain" I mean how much change in actuator position results from change in pressure. Insufficient gain will result (assuming max boost is okay) in the wastegate starting to open before you want it too - say 7 psi in your case - which will hurt boost response on the way up to 10 psi.
What's your turbine size / AR?

Barwick

Couldn't tell you the turbine size or A/R... the previous owner didn't know, all I know is T04E 60-1 compressor side, turbine side is unknown, that's all he had.

I'm not sure what size it is, but it's fairly large, BUT it's running a stinkin' long way from the pressure side down to the wastegate.

Where's the best place to mount the wastegate, before the throttle or after? I forget where it's mounted...

madsci

I like to connect it before the throttle. If it's
connected after, it's a vacuum leak, and also at part throttle it's possible to have the turbo making some ridiculous pressure, which then gets throttled down to 10 psi. Lots of backpressure that way. Connect it before the throttle, and the turbo will not make more than 10 psi (once the wastegate is working).
You might just want to buy the softer springs from Turbonetics and try them. I don't hink they're that expensive.

What kind of exhaust manifold are you using?
Also do you have a catalytic converter?

Barwick

not sure what exhaust manifold is on it, and there's no cat.

madsci

You might need to port the wastegate passage in the manifold... but first try a softer spring and see if the boost will stabilize where you want it. Don't worry about how quickly the boost gets to 10 psi at first - that's the next problem.