What would be the reason why a turbo is not biulding boost? All the vacuum lines are connected and everything else looks ok. Could it be because all I have is a 3" down pipe off of the turbo?
If it was my car I'd check the guage first, and if that isn't the problem take the turbo down and make sure it spins free, then start replacing vacuum lines (not like they are expencive).If its none of the above you might have to invest in a new waste gate
Posts: 7978
Joined: 9/1/2006 From: Regina Beach, Sask Status: offline
Its easy to check the wast gate, take an air compresser and set it to push 15 PSI only and turn it on the hose, if it moves then its fine, if it doesn't move, its blown
If it was the wastegate, then you would have an overboost problem since it's not letting any pressure to be by-passed. Check for a locked up turbo.
Not true. Wastegates have an internal spring and diaphram. If the diaphram is torn, youll make more than normal boost. If the spring is worn out, youll make very little boost.
Even with the wastegate wide open, youll still make a few PSI.
Post more info! What do you mean no boost? While driving or while reving in your driveway? See that you are running a straight 3" down pipe this is a valid question. If you are reving in your drive you will never show boost unless you are power braking (no load + no boost) Really need more info
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Turbos and boost - 
