cichlid43

Well on my way home from thanksgiving, im doing about 85mph, i see a car coming up behind me fast. It was an IS300 so i thought i would try to run him down, i drop to 4th,then shift to 5th.

the motors pulling strong all the way up to about 115(first time i've been this fast) when it's almost like a governor kicks in. I tried this three times with the exact same results. It's a 99 z28, please help.

2001NBMZ28

Maybe you're hitting the speed limiter - look on the driver's side door and see if it came with Z rated tires.

cichlid43

My car didn't get the z rated tires, i looked at my tires and found a T on them, looked on the net and found their rated for 118. Is Their anyway to disable it?

Jon7I2

That sucks that GM even sold our cars w/ anything less than z rated tires, but to top it off they put a govenor on it. I would hate that. There has got to be a way to disable it.

Revelation Z28

iTrader: (10)

a tune.

1sick'98WS6

iTrader: (19)

even a hypershit programmer will zap that, just get it tuned if you have anymods done

cookie

yea a programmer will help. i have one on my 98 Z and i can do 165 mph. when befor i could not.

staringback05

iTrader: (8)

uhh....how bout this...what rpms is the car at, at that speed?....and it honestly sounds like a fuel pump/injector/pressure problem

subtlez28

iTrader: (15)

I also think U R hitting the factory speed limiter. Any tuner (superchips-hypertech) or person w the edit software can elliminate this.

yak

iTrader: (15)

watch out with tire ratings. I had a free set of tires that were H rated I think and I did 135 on them. afterwards I was like hmmmm, I wonder what those tires are rated? sure enough I should not have done that, I was just happy i didn't blow one out.

Beaflag VonRathburg

iTrader: (176)

Yeah, I agree. Pushing tire speed limits is scary ****. Imagine a blow out at 115+. I did that one time in my old eclipse GST 130, hit the limiter and found out why it was installed from the factory when I got home. Well the guy who bought the car before me put cheap *** T rated tires on there. 130 on a 118 rated tire = I almost crapped myself when I found out.

JimMueller

iTrader: (9)

After replacing your tires with W-, Y- or Z-rated tires, then remove the speed limiter through tuning and then drive 120+

2000LS1TA

iTrader: (26)

Z rated tires here, and she's seen 150

Trev_SS

iTrader: (17)

yes you need to get a tune to get it going to pull speed

staringback05

iTrader: (8)

you fellas do realize his car wouldnt be hitting a redline at 115 mph....our cars do the whole speedo, before that happens....its a mechanical issue

JimMueller

iTrader: (9)

My car came with non-Z rated tires from the factory and had the ~118MPH speed limiter. Flashed another VIN's calibration into mine (donor car had Z-rated tires from the factory) with a Tech2 at a dealership and the limit was removed. So the PCM is a mechanical issue?

staringback05

iTrader: (8)

anything that has to do with a physical part is mechanical.....a limiter in any format is a software or programmed issue....my tires will do the speedo....fuzions