06EvoIX

This one might be a little tough to figure out but is essential.

Ok so, I'm the original owner of a 2006 evo ix. I bought it in october of 2005. Has 75 thousand miles on it.. Have multiple modifications. To simplify, I have every bolt on except turbo injectors and manifolds. I've been pushing 350 whp for a couple years now. So I know how fast my car is and where the power should be. But recently, within the past year and a half. The car has lost power. And I can't find out where I'm losing it. I've rebuilt the transmission, and had my acd checked out. Replaced the acd pump also. For other reasons. Anyway from a stop the car pulls very hard. But from a roll or pretty much 4th and 5th gear feels really sluggish. When I floor it I can feel the car isn't putting power down smoothly. Its rugged. Multiple shops have told me that my turbo has shaft play. Can I lose a significant amount of power from shaft play? And over all drivablitly has decreased. It performs like crap. Another thing is that my vacuum at idle has been decreasing and fluctuating when it never has before. Also I feel grinding in the front wheels. Could wheel bearings be the cause of the sluggishness? Or is it from the engine. Its gotten to the point where a stock rsx can keep up with me on a roll. Its never been this slow. I don't know if I should increase horsepower without destroying something. How can I find out where I'm losing power?

FedEvo8

Sounds like a boost leak somewhere. Have you done a boost leak check yet? Check the plugs too to see if they're fouled up.

06EvoIX

I've done boost leak test and leak down and everything is normal. I haven't checked if throttle body or injector o rings are leaking though.. But what I would like to know is if shaft play can cause sluggishness. Also the car has been in 2 front end collisions.. Nothing major.. Only rim snapped. But could wheel bearings also cause sluggish.. I have a feeling it's a number of things.. It just seems that the engine is working a lot harder than it should for the power output it has. Especially when rpm is above 4000. Maybe clogged injectors? I plan on getting 880cc injector, fuel rail, cbrd bbk full turbo and new spark plugs. Then tune.. Is there anything I should have inspected before installing these things?