i was so impressed by the fact of runnig @ 180 degrees that i went for broke on the interstate and tried to get the b****** to overheat at 120mph it seemed to have lost its umph seems like a compression thing,kinda weird i slowed and everything seems to be normal good news ,it only rose to 185 190 in the process,that air dam was the cure thanx fellas, still got a few bugs after the swap but man im tellin you, this **** aint playing,why would it do such a thing

 

Are you atill using TBI? Still running a stock PROM? Fuel cutoff on a stock PROM is in the area of 118 MPH.

 

With the exception of the 88 I think all the following years had the speed limiter set to various limits. The 88 years tehmselves are naturally governed.

 

no computer crap at all straight 350 w/ a performer intake edel 500 carb mallory dist and coil small cam all good except for this and belive me there were some bugs

 

Speed limiter? I'm the original owner of my 88 LB9 IROC. When I got it, and soon after break-in and first oil change, I took it out on the back roads to see what it would do. It was still accelerating through 135 when I chickened out. Mind you, the car was stone stock when I did that. No tweaks or mods at all.

Doesn't look like my car has a speed limiter.

 

Your IROC came with the 245/50 high speed rated tires. These cars didn't get a limiter. The cars with "regular" tires like RS's got the limiter.