Today on my way home from work i decided see what my car could do. Its a 96 lt1 with a 6speed. According to my gps i hit about 117 mph and when it hit that speed it just kinda bogged or something. Tried it 3-4 times and it happened every time. There was plently of gear left so i don't know whats going on.

 

If it came without z-rated tires, it would be limited to about where you are feeling it. The PCM would have to be reprogrammed to remove the limiter.

 

that sounds way too low. check engine light on? fuel pressure ok?

 

As Rob/Shoebox noted, if the vehicle did not have the Z-rated tires when it left the factory (RPO "QLC"), it has a speed limiter. Over the various LT1 years, the speed limiter factory setting varied from 108-116MPH. Sounds like you have one. If the car had the "QLC" Z-rated tires, it has a speed limit setting entered in the program field, you just can't reach it because its the largest possible discreet 8-bit number = 255.

Check your build code tag for the Z-rated tire RPO code.

 

your car came with original Goodyear Eagle GA tires 235-55-16. These tires are speed rated to about 116mph, so your car would have a speed limiter equiped with these tires. The 245-50-16 Goodyear GSC z rated tires were optional on the z28 and the car's had no speed limiter. There is nothing wrong with your car, just have the limiter removed.

 

Would an 87 T/A have a liMiter?