Hey guys, most of you have read my post on how I thought I hit my rev. limiter in 5th gear, well, I hit a limiter, only it was my speed limiter. How can this be? Its a 1997 Z28 M6 (obviously). It has a 150 MPH speedo in it (stock). I bought the car used, so I can't be 100% for sure what is done to it. Thanks guys. noah

 

It either originally did not have the 112mph limiter and has, for some reason, been reprogrammed with the limiter. Or much more likely, somone changed the speedo face. You need Tunercat or LT1_Edit to fix this.

Rich Krause

 

Really....hmm, that kinda bugs me. I was never told of this, but maybe the guy I bought it from wasn't either. Thanks though. Noah

 

It's very possible that it came with the 112 limiter all along. A simple tune will get rid of that problem unless you wanna spend the money buying a hypertech. (Not the best solution IMO though.)

 

I actually had this happen with my Formula. I had the 150mph speedo, but I also had the limiter. Check the door codes on your driver side door. If the factory tires were 235s, then it would have had a limiter. Tunercat fixed it quite nicely though...

Travis

 

I thought some of the M6 cars came with the speed limiter did they not? If the buyer didn't opt for Z rated tires I'm pretty sure all of them got the limiter...but the M6 could have come standard with Z rated tires...

 

yeah this is what I thought too, if your car didnt come with factory Z rated tires, then you have a speed limiter.

 

Hey there, remember me? I'm the "dumb-dumb" who suggested you probably had a governor in your car.
Look in your glovebox for RPO code QLC or QFZ; if your car don't have either one of those, it came from the factory with a governor.
Oh yeah, another thing... If you're car came with non Z-rated tires, they would be P235/55R16, which would be about 1/2" taller than the P245/50R16. If you have the latter tire size now, your speedometer is going to read a little high, HTH.

 

if you filled in your profile someone close might fix it for free. I would but don't know where you are.