New to board.
'91 camaro RS 3.1 auto/ trans
My tach says that idle speed is around 1500 RPM
Normal driving engine rotinly pulls 6000
When I get on it.....RPM's are in the 8000 range.
Tach only goes to 7000 but it easly hits the peg on the tach.
Also 1st gear=20mph=7000 RPM
3rd gear=70mph=7000 RPM
Stock car. to my knowledge....3.23 rear end
I've done the math/ and compared to others.
Just doesn't add up.
Is my Tack off?
For some strange reason I don't think that I have 7.34 gears in my stock 10 bolt rear end!!
Any 3.1 owners with RPm vs. speed Number would help me greatly in figuring what is wrong and where.

 

Let's see.......I am pretty sure your tach is WAY off! LOL! I don't know if my rpms and everything will help you because I have 3.42 gears and a 5 speed but I will say about what mine are. I am about at 3500 rpms at 20 in first, 4500 at 70 in third. These are just what I believe, I could be off a little. But one things for sure, your tach is way off and if it wasn't, I don't think your engine would last thru too many 8000 rpm WOT'S! Two options, get your tach fixed (guessing the tach sending sensor) or get an aftermarket tach and connect that. Good Luck! Oh, almost forgot, WELCOME TO THE BOARD!!!!

 

hi, i have 3.42 and a 5 speed
for me 3rd gear is 40mph at 3000rpm. 60mph is4th gear at 3000rpm, 5th gear 3000rpm is at 75mph

 

where do you idle at?

cuz my tach is screwed also, but no where near that bad

lol

 

I have a 1992 3.1 Liter, and when I am cruising at 60 MPH, my tach reads 1250 RPM. I always though that was quite low, especially since I know it was a 3.23 gear from the factory. I had to replace the ignition switch once, and when I dropped the steering column down, the reason that the RPM is off became apparent. The gauge cluster has a sticker on it that says it is for V8 application! It has to have been this way from the factory, since i have never messed with it, the dealership has never messed with it, and i bought the car brand new. I thought that was a pretty cool fluke, so I have never changed it.

I would have to say that your tach is waaaaay off. I have seen this happen before when a friend's car did this. The actual gauge had a short in it that caused it to read about double whatever the engine was actually turning.