I have just aquired a 93 Z28 that has had EXTENSIVE drivetrain work. The problem is that the car boggs or hesitates on the green light at the strip. It is a sleeper/daily driver. Let me first include what mods I have on the car. ATI D1-SC ProCharger (240-280HP w/17-22psi),12 rib pulleys and twin intercoolers, Eibach suspension, the original LT1 stroked to 383 (480HP), dual stage NOS (75+75) w/purge, custom built airbox, cold air intake, griffin radiator, custom built 700R4 w 2800 stall, Moser12 bolt w/355 gear. ZR1 wheels with MT ET's on the back (13lbs). Borla catback exhaust w/headers. Conservatively looking at 850Hp on the bottle.

The car runs fine if I am already rollling or once I get out of the blocks but it hesitates when I go to WOT from the line (using NOS off the line does not help)??????? What has not changed is the injectors...(stock 24lbs) and the throttle body. Now the car is fast...but it should be FAST!!! It is running high 7's in the 8th when it should be running high 8's in the quarter! What is causing this hesitation bog? I checked the system for leaks and the plugs look good. It sounds like it is starving for gas. I have worked on a lot of cars but my knowledge is limited with fuel injected PCM motors.

 

Mayb your blowing out your spark ? Have you tried closing your SG gap some?

 

No but I will tomorrow. Are there plugs better suited for my application? Then again, the bogg/hesitation occurs before the supercharger (3000rpms) or the NOS has a chance to work.

 

what plugs are you running?

 

Also your prolly not getting enough fuel . You need much bigger injectors . That SC should've come with 83lb injectors from ATI . what compression ration do have. Do you have a tranny brake, are you properly launching the car considering the 2800 stall, what ignition set up do you have.?

 

If you are still running 24 lb injectors with 20lb boost + spray, I am surprised the car runs at all let alone bog. I don't know what your PCM tune is like, but it appears it may be too rich at low RPM and starving at high RPM. Probably to compensate for the undersize injectors. With those mods you should have 50lb+ injectors at a minimum.Thestock fuel pump may not be able to deliver enough fuel.. Also, a PCM tune is needed whenever doing major mods to a computer managed engine.

 

Ordered some 83lb injectors this afternoon. Will post when I get them installed. Also checking the fuel pressure flow (at regulator)in case another pump is required. I will have the PCM reprogrammed when I get the injectors installed.