coop

First of all, I have done searches and I didn't see anything that answered my question, if there is something out there, just post the link please

Ok, so I am looking at waste gates, it looks like HKS sells them but you have to choose the size (in psi) that you want. Is that the max PSI it can keep stable? If that is the case why do they offer so many options in psi sizes? I mean, if it can control 20 psi then it can control anything less than that....right?
Is it better to port the stock wastegate or upgrade?What psi can a ported sotck wastegate control?


Also, what psi can the stock turbos opperate at (if engine gets correct amount of fuel) ?
What is the amount of psi the stock apex seals can handle?

I need to get my boost under control, I have a profec b on the way, and I am boosting to 13psi with only an Intake, dp, and smic. I will be getting a new exhaust and ECU... so I can only imagine I am going to get into creep problems...(I already have them!)

spooledUP7

I cannot speak for the HKS but with the stock, 7psi is the spring resitance setting. The spring will hold the wastegate door closed enough to maintain 7psi without assistance from a boost controller. A boost controller then plays with the pressure against the spring to bleed or add pressure. A 20 PSI wategate actuator sounds like for use with a big turbo, or heavy mod setup. Technically even the stock wastegate will allow you to reach well past 20psi by not connecting it all to the pressure source.

maxcooper

External wastegates won't work with the stock turbos. Unless you are installing a single turbo or custom (non-stock based) turbos, an external wastegate is of no use to you.

The pressure listed is the spring pressure, or the pressure you would get if you hooked it up with no controller. You can control it to run higher than the spring pressure, but not lower. The stock turbos have a spring pressure of about 7 psi, but they are controlled to run about 10 psi. You can go higher, but 7 psi is the lower limit for boost with the stock turbos.

Porting the stock wastegate helps avoid boost creep (boost rises in high gear/load, despite the wastegate being fully open). You can get boost creep if you open the intake and exhaust opened up all the way (intake, dp, mp, cb). Search for "boost creep" for more information.

The old wisdom seemed to be that 15 psi or so was the limit for the stock turbos, provided you had all the supporting upgrades like fuel system, ECU, IC, etc. But a few people have been able to run them higher since then to get bigger dyno numbers and run some excellent times at the drag strip. Still 14-15 psi is probably the limit if reliability is a concern for you. Most of the those pushing the limits have moved on to single turbos after the motor popped, I think.

-Max

Hyperite

Not to get technical, but an external wastegate would work with the twin turbos, but only with a different exhaust manifold (read- $$$$$$).
~Tom