Okay, so I need some help! I have a 1980 Camaro with a Turbo 350 transmission in it. My speedometer is off. Like, way off.
So i run 4.10 gears, with 245 70 15 read tires. The Drive grear, i think, is 8 (though its blue i think).
I did some math and bought a Yellow 24-tooth Driven gear. My speedometer is like 20mph off when i'm over 60 and like 10 off under 60.
I picked up another gear, this one a red 21-tooth and it too seems very off.

Any one know what should be in the transmission for a Drive gear? Or, does anyone know what it could be? I'm sick of guessing at this one.

Please help!

 

Try this: http://www.bgsoflex.com/speedo1.html

 

Well if you figure out what you need post it up here before you buy a new gear. I have a ratio adapter here that I'm not using and it might be something you can use.

 

What ratio is it? With 4.10's, I got tired of mine reading 100 mph around town, not to mention the speedo sounding like a helicopter! I disconnected the speedo and just drive off the tach (something else I haven't gotten around to). Keeps the mileage low though!

 

Now that I'm home I can tell you exactly what ratio it is. It's a 1.0 : 0.833.

So I assume it slows down the speedo by roughtly 27.7% and not speed it up.


You know they make programmable boxes for speedometers too right that you can set up? If you want to spend 300 or so bucks..

 

Yeah.....if I wanted to.
I'll figure mine out to see if that ratio works. I have a feeling it's not going to be enough of a drop though....mostly because yours is a .833 which is about a 17% drop, not 27%. 83 + 17 = 100.
Don't forget to leave an apple on my desk too!

 

my speedometer reads like 80 miles and hour at whats really like 50-55 mph. Both the yellow and red are doing it. i think the red is way higher though. The yellow driven gear is to high is tooth vcount though that i cant go any larger with the turbo 250 tranny. All the others are for a turbo 400......

 

Ha ha, I did that to see if you were paying attention!

 

Ha...ha...ha...you almost put one over on me that time. Yeah that's it!

 

I thought 350 turbos had the little metal gears.i know 400 turbos have the color coded plastic gears