White95LT1

I own a 95 Z, A4, bone stock...shuts off at 115.. I had always thought Z's didn't shut off that soon much less shut off at all. ...Just curious is all..

KillWhitey

I think they put fuel shut-offs in early LT-1 Z28's that had cheaper tire options with lower speed specifications.

You can write down your Vehical Identification Number and take it to the dealership and they can tell your car came with the cheaper tires.


Tim

White95LT1

Programmer still have the same effect to raise/remove it?

cdb95z28

If it came with the Goodyear GSC 245/50ZR16 tire as an option, there is no speed limiter. And you get the 150mph speedo. I`ve had mine to 140

White95LT1

yeah...well mine deff. shuts off...already checked that out..lol..but yeah it came with Goodyear's....and that size...but no luck with reaching over 115mph....gets annoying trying to play catch up

cdb95z28

Did You look at the Service Parts ID sticker in the glove box?
QLC is for the 245 Goodyears
QMT is for the 235 Goodyears/115 speed limiter.

Did you buy the car used? Maybe a dealer in the past did a computer recalibration and screwed up?

KillWhitey

The tires would be the same size with just a different speed rating

"Programmer still have the same effect to raise/remove it?"

yes

cdb95z28

...or maybe because it`s an auto Is it possible GM did things differently with the autos???

cdb95z28

In `94 there were no other 245 tires. In `95 you could get a 245 all season as this was the first year for traction control. In `94 the standard tire on Z28s was the 235/55R16 "touring". The "performance" tire was an option-245/50ZR16. And that was only available on the coupes.

White95LT1

alright...thanks people...just wanted to get info before spending money on a programmer..as for it shuting off at 115 cause it's an auto..no..buddy of mine has the same yr model with a A4 and it doesn't shut off...and Yeah I bought it used..only had it since late Oct..havn't had time to do anything do to the Hurricane..

Injuneer

Its not because its an auto. Its determined by the speed rating of the tires that came on the car from the factory, as several people have already explained above. Doesn't matter if its a coupe, a t-top, an A4 or an M6.... if it doesn't have the Z-rated tires, it has a fuel cut speed limiter built into the PCM. The limit varied over the years, and ranged from 112-117mph.

If you look at the program for the cars with the Z-rated tires, there is a number entered into the speed cut-off field, but its "255" = the maximum number for an 8-bit field.