Hi I have a 94 Z28 with the auto and trying to figure out my power lose. I run my car maybe once a month at the local drag strip (1/8th mile). I have owned the car now for six months and last year the best pass was a 9.11 with a 2.05 60' at 79 mph. This year ran a total of 5 times and best pass was a 9.23et 2.12 60' at 77 mph. I have done plugs and wires, it has a CAI, computer tune, and KM and the 3:23 gear. This year I changed the opti spark out. So I thought the motor is getting weak so I had a compression check and each cylinder read 125 to 130 dont know it that is good or not. Mechanic that did it said it was fine. I have seen some stock LT1 auto's run anywhere from a 8.95 to a 9.05. I just figured that my ought to run as good or better. I dont know alot about them I am learning from this web site and other LT1 owners. One of the problems I thinks is its running rich. When I first start it I get some black smoke. Another problem is it seems a little slow getting into the higher RPM's around 4 to 6 grand. One last thing I do know, my trans is slipping because sometimes it hits the rev limiter before it shifts from low to second. Could the trans be my problem or something else. Just curious if anybody has any ideas.

 

I know one thing, your tranny is not slipping. If you get an aftermarket tach, you will see that the stock one can't keep up the our motors. Basically if you are at WOT from a 1-2 shift, the motor is turning faster than the tach, but the revlimiter still catches it.