wilddawg

My car rev limiter is set at 6500 rpm. It acts like it hits the rev limiter at 5500 hundred rpm. I figured the tach was slow but even in higher gears it does this. I took the car to have it tuned and dynoed yesterday and it was bad lean but it did the exact same thing on the dyno and I could hear it just lay down at that rpm. The tuner then asked me if it did the same thing on the street. everything electronically checked out and the dyno tach showed the same exact rpm. THe car made good power up until 5300 hundered then drops off like it hits the limiter. At this point it made 337hp and 347tq at the rear wheels. Could I have a broken valve spring or bent pushrod or valve cause this to make the car stop making power at this point and shutter the engine.

WetChicken

iTrader: (1)

I think a bent pushrod or valve would give you a tick that you would hear at any RPM. Floating the valves would give you a sharp rolloff at the top end, so that is possible.

Very nice numbers! What has been done to it?

I had mine on the dyno last week and it was rolling off at 5300, but you describe it like something is restricted, such as fuel or air.
Double check your air filter and inspect your exhaust (Including a plugged cat), and watch fuel pressure once you get to the high rpm's.
What year is the car, how many miles, and do you know if this thing has been beat on?

wilddawg

the car has pacesetter headers and ORY with a borla catback exhaust, SLp lid all the free mods, Irdium plugs, msd wires

Nine Ball

iTrader: (38)

does the fuel cut off, like hitting the rev limiter? Does it do this in every gear?

Maybe you are getting valve float at high rpm, due to fatigued valvesprings.

MavrikTA

iTrader: (27)

I vote valvefloat.

wilddawg

it does this in every gear. I think you guysare right. I have80,000 miles on the car

BES Stroked Nova

iTrader: (24)

before i did my cam, with just an ORY and a hypercrap, and 126k miles on stock motor, i was reving my car to 6400 RPM shifts. i did this b/c everytime i up the shift points it went faster. by that RPM's i thought was high enough!!! lol

has the car ever been over reved?? cuz i am guess something in the valvetrain.....

'Trust'

iTrader: (24)

Yea, valvefloat on 80k is rare, but i could happen. If you haven't over reved it (shifting into 2nd at WOT opposed to 4th) then I vote valvefloat.