what is the governer set at for a 1985 Camaro iroc-z? The engine is a 305 tpi (LB9). Does anyone know why the speedo only goes up to 85?

 

Don't know for sure. In later years GM put a fuel cut-off just below the rated speed of the tires that were installed on the car at the factory. Don't know if they did that in 1985 or not.

The 85 MPH speedo is a hold-over from the gas-shortage days of the 70s (yet another thing we have to thank Ralph Nader for). I THOUGHT that Z-28s came with a base 85 MPH speedo (one of my brother's 1985 Z-28s has that speedo with the low-output carbureted LG-4 305) but could get an upgraded one depending on the options that were chosen, but again, I'm not certain of that.

If you want to know if there's a fuel cutoff you will need to either go run it on a high speed track or do what I do.... Put the rear end on jackstands, plug a diagnostic tool into the computer (which will tell you the true MPH even after the speedo on the dash pegs) and run it up!

 

I don't recall them being governed. Pretty sure they topped out at 138-141mph. The '85 TPIs (A4) had a little more kick (215hp I think) than most later year LB9s (cam change).

 

On the later thirdgens there can be a limiter. It was a function of having or not having the speed rated tires. My current '90 was originally a LB9 G80 car with factory Z-rated tires and it has no limiter (actually it does, but it is set so high that it can't be reached). Don't know about the earlier ones, though. My '84 L69 Z-28 didn't have one and it didn't come with speed rated tires, either. Anyone who looks at the Proms on the older cars should be able to tell you if there is a "limiter" on your car or not.

 

from what ive been told very few gm cars or trucks had gov's, until 1989. dont quote me, i could be wrong, just what ive heard.

 

85 was one of the best years for the I-Roc Z 305 engine.. true it has no speed limiter on it...

And true is does have the hotter cam....corvette cam in 85....then then went to the horrible LG4 cam in 86....

YOu should run 15.30-15.0 in the 1/4 and go about 135-140mph top speed..... with the 3.08 gear....

 

The top speed of a car is determined by the amount of power you have and the gear ratio. Its a simple fact that if you run out of power your car can't go any faster because of the tremendous forces imposed on it by having to move through the atmosphere. I have gotten my car up to 148 mph (considering that my tach is correct at 5000 rpm) I have 3.73's and I put out as much power as a lightly modded LT1.

 

No governor in mine. Noooo, I get the stupid won't shift into 4th gear at WOT problem. One of these days, I'm gonna get that changed.