HP Junky

Well after pulling plenum, turbo and exhaust manifold I finally found the problem. See if you notice it.

There is no cat at all in the system. Haven't had it back on the dyno yet. Pulled turbo and manifold off very very small exhaust leak on rear 2 cylinders but not enough to cause a problem. Turbo looks good. Removed plenum to replace gasket no leaks found but replacing gasket to be sure. When I get a chance I'll get it back on the dyno.

Pulled center section of the turbo to tail pipe 3" exhaust off no cat no restrictions in rear muffler. Pulled inlet plenum off to check gasket as it was very hard to tell if it was or wasn't sealing might have had a very small leak but don't think it's the problem. Going to pull turbo and manifold off next. Checked cooler and piping for leaks by pressure testing. Once exhaust side is off I will be doing a leak down test as it will be easier to hear leaks through each port. Will post out come of all tests and inspection.

The green line at the bottom was from not ending power run before throttle was let off that's why it's there. Boost in the car is 15psi. I'm going to drop the exhaust tomorrow and have a look. Then move on with checking cooler piping, plenum manifold gasket and everything in the whole setup to see what the people before did or didn't do and just make sure everything is working correctly. Thanks for all the replies.

OIt makes 15psi of boost on the graph that's the lower 2 lines. I'll check the cat it looks like it has a small one but could be missing as it's a dedicated track car. Here's some pics. I'll check the cat when I lift it up to run new fuel line. Will let you know. Thanks.

I finally got a friends r33 gtst on the dyno today and he was telling me it lacks power in the top end. Rb25det fair. Hks pod. Z32 AFM apexi power FC. Upgraded turbo not sure on size smaller than a gt3582r. For facing plenum 80mm tb e85 1000cc injury 15psi boost 3" Full system including dump pipe. Was tuned by a shop and gave a dyno sheet that showed 313rwkw. No today on the dyno it pulled 205rwkw. Haven't investigated yet but any ideas what might have happened timing not advancing or some stupid little think before I go full surgical on the car.