Pulling strong...then losing power

[evil_gsT]

I recently put together my 97 gst with a lot of new parts. (everything listed in my profile, its all new) and i am running off the wastegate pressure, which is about 10lbs. My car pulls very hard up to about 4500 rpms, then falls on its face and feels like a 420a or worse. When I looked under the hood, the only noticable thing that where the j-pipe goes into the turbo, the left bolt is missing, and part of the gasket has slid out, but the other one is tight. Could this be the cause of my power loss? If not then what does anyone suggest?

Thanks

[Ceddy]

You are not going to hold boost if you J-Pipe isn't connected correctly.
Running with a huge leak cause the turbo to over-spin and shorten its life.

Fix J-Pipe, do a Boost Leak Test, and get a real Boost Gauge if you don't have one. Don't drive your car with a huge leak, or you may be pulling your turbine wheel out of your exhaust pipe.

If you have problems tightening your J-Pipe bolts, you can replace them with Allen Head ones, its easier to get an allen in there depending on which J-Pipe you have.

[evil_gsT]

Ok, thank you. I do have an Autometer boost gauge.

[doctor_shock10]

sounds like a big boost leak, blt and fix the j pipe problem