I bought a 99 z28 auto hardtop it wont go over 120 ? my 99SS my would peg out the spedo what gives ?

 

What tires came stock on your 99 Z28? If they are not "Z-rated" for high speeds, the PCM has a speed limiter set to about 118MPH. Your 99SS came stock with Z-rated tires, so the speed limit filed was maxed out at 255.

 

Im sure not z rated tires ! so I guess that's the issue. I also found out the alt is going out. I ready the top speed was 157 for a 99 SS ? Ive had it past 155 but didn't have a gps.

Well guess I need a tune an delete the max speed cut off .... 300 reasonable for a tune ?

 

http://www.madtuner.com/index.php?op...id=3&Itemid=26

Camaro & Firebird

 

thanks couldn't reply earlier just had shoulder surgery...

 

I shouldn't be $300 just for that, that to much.

 

ima get a tune an put my tta wheels on it with hoosier DR's
it cant run over 120 1/4 mile stock

 

??????????????

I don't think anyone was suggesting that a stock 99 Z28 would turn 120MPH in the 1/4-mile.

 

im saying im getting the 120mph off 200 shot with hosier 15's