Can anyone tell me where I can find one. I want to check mine now that I have changed the rear end gears.

Thanks,

Raul

tci website has one

Thank you very much for the link. I came out with 4.685% with the 4.56 gears and 4.764% with the 4.86 gears. I guess I'm in pretty good shape.

Raul

Raul

---

don't forget about instrument errors on electric tachs 3 to 5 % is considered good on a race conveter, I know guys that will do anything to get one better than 3% My 10 inch calculates to 12% by using RPM and tire circumference the old way, I really wish that I had a data aquistion system on the car that would accuretly measure drive shaft and engine RPMs, that would tell me the real slippage in every gear and on the gear change

---

that is nothing that money will cure.

But...
you don't need any more than a pencil and a cocktail napkin if it's just a comparo between actual RPM (observed data) and predicted RPM (from tire OD + gear).

What's missing is tire expansion - which varies with MPH and all tire variables (pressure, rim width, # of plies in carcass), but not completely linear (how fast does it have to turn before it's reached maximum OD?) and always tends to reduce the apparent slip because it lowers RPM.
If you have a Goodyear rep, ask him if expansion data is available for your series.