ok so here is the story my buddy has a 87 supra with a 7MGTE he just upgraded to a bigger turbo Garret GT35R… he has all the supporting mods one would need for a turbo upgrade but hes not making boost… hes got a 60mm wastegate that was stuck open at first so we though that was for sure the culprit but after fixing that still no boost… hes checked for exhaust leaks, vaccum leaks, all kinds of leaks, but nothing… could it be that the wastegate is just too large??? 60mm??? i dont know the first think really about boost and hes tried just about everything so help!?
What type of spring is in the wastegate? If its too soft then its going to bleed too early and the car wont make boost.
I dont think Ive ever heard of wastegates being too big, its supposed to bypass exhaust gas so if its closed it doesnt matter the size it should build boost. Have you tried running it with no vacuum source?
What make is the wastegate?
my buddy says hes got very stiff springs and hes adjusted it up and down trying to make it work but still no luck… the wastegate is a Turbonetics Racegate Wastegate 60mm… we’re running out of ideas
anybody else have anyideas??
Boost leak… if the wastegate is open… you should be able to hear it.
Yes, boost leaks are one possibility which could leak all your boost pressure before it hits the intake mani.
Check all vacuum lines again, and do a boost test to ensure there are no leaks.
Secondly, just wanted to make sure, his boost gauge is hooked up to a pressure source correct?
Also, is his wastegate dumping to the atmos? Or recirculated?
You would be able to hear it if the wastegate is stuck open.
Lastly, if it all these things check out ok, I would pull off the filter and inspect the turbine shaft/wheel.
wastegate is dumping into the atmos for the time being… you can totally hear the wastegate almost scream but no boost…
even at like 1psi can you hear the wastegate dumping?
It should be opening up at the spring psi.
If you are saying that it is opening up early, that could be your problem.