My LS1 seems to be slow to me now. I took it out for a quarter, and it just isnt running the same. It seems like it doesnt want to pull any faster after 4000 RPM's. It feels like it is topping out. I got maybe 100 MPH in the quarter. That seems slow considering my moms CADDIE gets 95.

 

what elevation are you at?
thats important to know...

the lower you are the faster..

best way to fing out for sure is DYNO and TRACK runs..

 

There could be 1001 reasons why.
First off,
1.Did you purchase the car new or used?
2.Whats the mileage on it?
3.What are your driving habits?
4.Do you perform proper PM?
5.What brand/octane gasoline do you use?

These are some questions just to get you started thinking and maybe help us help you.

Mike

 

Must be something wrong, my '02 pulls harder and harder to redline. Comes alive at 4k RPM. Sounds like something is retarding your timming. More info would help like stated before. Later>>>>>>