| According to a number of people in the know, the wastegate actuators that come with the 530's are fine if you're only going to use street gas. They come preset to open at 12 psi (or are at least supposed to.. there have been a number of them preset to lower), and with a boost controller hold to 19 or 20 psi without too much problem. However, from about 6k on up, the boost starts to fall off... the springs in the wastegate actuators just aren't strong enough to stay shut at that level of air flow I sent this e-mail to Greg: "Mark Leader [SipiriZ] just sent me a very detailed e-mail regarding the 530s not
being able to hold full boost all the way to redline above 6k rpm. He
said that it has to do with the stock wastegate cans not being strong
enough, and that he recommends getting some stronger wastegate cans. He
told me to ask you for feedback about this. What are your thoughts?" His response: "Well, This depends on what you consider full boost. With Pump fuel this is not acturate at all.
With Race fuel they will only hold 20 psi well with the wastegate cans they
come with. The turbo peak at 24 PSI......They will fall back after about 6000 RPM
because the back pressure is greater then the wastegate cans ability to
maintain the pressure.
This is really a safety valve to keep from making too much heat and cooking
your motor. People like Mark like to puch the MAX limit of a given set up....This can
be dangerous you cause premature wear and failure of the parts.
I feel the wastegates provide a reasonable range to use these turbos and
feel they are fine.
If you want to push to absolute limit of boost these turbos can make you
can purchase HKS actuators....I am not a HKS dealer and I am not sure how
available they are. I have heard they run about $200." Speaking with ash, he recommended using the HKS units... esp. after the debacle of tuning the two 530bb cars with loose actuators.
Decision time for me....
When all is said and done, I'll have about $25k in this project (not counting purchase price or the full repaint and rims). The hks wastegate actuators are $200.. less than 1% of the total cost of the project. At this point, I don't plan on running race gas too often, but when I do, i want to be able to hold 24psi all the way to redline, as long as it doesn't detonate (hence twin EGT gauges, fuel pressure, boost, and engine temp gauges). I'm going to disappointed if i don't get 500rwhp out of this... regardless of how much boost and what fuel i need to run to get out of it... if I don't have a dyno sheet with at least that, i'm going to feel bad.. hopefully it'll be mid 500's, but that's wishful thinking. Maybe i could get 500rwhp out of it with the stock actuators (which is, i believe, what JWT uses). If i didn't, i would certainly pull the engine again and swap out the actuators. This saves me from an engine pull :-)
Joe
Engine Rebuild in Progress: Sport 530bb's + Inconel :-)
AIM: hoyatiger81
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