There's a boost leak somewhere, check all connections everything else seemed OK. Don't know how to check if the wastegate is the problem.

 

A wastegate cant make a boost leak

A wastegate isnt under boost. The wastegate is in the exhaust system. A boost leak will make a whistling noise in some cases.

To test it you would pressurize the intake system with the car off. Take the intake off and hook up a connector to the turbo inlet and pressurize the intake with an air compressor. Look at the boost guage and wait till you get around 25-30psi and then let it hold it there. You will hear any boost leaks if any and if your not sure spray some water on the suspected spot and see if it bubbles or anything.

How do you have 600+ HP and not know this just wondering

 

600+hp is my C5
Anyway, in response to your question I just drive them, don't work on them & don't fix them. I do work my az off to PAY for them.

I guess I should be checking the BOV.

 

well if the wastegate doesn't seal properly it won't let the car build boost.

 

Why are you assuming it is leaking? I wish i made the money to pay for it all too
Id never work on the damned things... anyways, i would first think of why you think it may be leaking... perhaps it is just lower boost than you want or something else. Normally a boost leak will still make it so you can run the same boost.. the turbo just needs to push more air to get there because some of it leaks out. If the case is your boost is too low I would check the exhaust and wastegate and boost controller. If your boost tapers then I would think about what type of controller you have... if its electric is could be that. If not, then maybe you do have leaks... I wish it was an easier topic to figure out though. I hate gremlins like that.

 

Have you run the Corvette at the strip? If so how did ya do? I love those things.

 

My car has the AMS 3076R w/ AEM, boost controller w/ low (20lbs) and high (25lbs) setting etc....

It's been running fine for about 14,000miles, pulling hard like a 400whp should.
I recently noticed a sharp drop in power, took it to the dyno and it only pulls 226whp & 160wtq, boost gauge shows about 15lbs max boost, AFR at 10.7 likely from the boost leak.

As far as the C5, don't have the ball to take it to the track yet. My start is awful and I don't want to embarass myself. Similar setup have yielded low 10S to high 9S.
Power is a little more than 600+hp, it's a blown 427.