My 93 Z32 is having technical difficulties. Can anyone lead me in the right direction for troubleshooting? At 4-5000 RPMs this car stops reving, like it is falling over and the waste gates open......If I bring the car up easy with no boost pressure it will rev to 6500 RPMs. I have checked the hoses and am at a loss. The NissaN dealership was no help. This car has brand new O2 sensors, new NGK plugs, brand new JWT ECU with boost jets. I ran a self diagnostic test through the ECU and it showed code 55 so there are no problems detected with ECU. The car has Stillen side-mount inner coolers, high flow intake, Megan exhaust. I appreciate any feedback. Thanks!

 

Hmmm. Could be your turbos. I was having a similar problem, not quite as bad as you describe, but it felt like the car was falling flat on it's face above 5000RPM's. I'll be posting some pics of my turbos in the next couple days. The thread is titled 'mod updates'. Do a search.