another gear question

Speeds it up. Your RPM's - and driveshaft speed - will be turning as if you're going 85. But the 4.10 gear will only be moving you along at 75'ish.

Speeds it up - I had a 4.57 gear in my 72 Mustang.

Allow me to ramble on MUCH too long because the Monday Night Football game is not very interesting.

Hmmm...trick question.

Well, the odometer will still move at the same speed when the speedo shows 60mph before or after the gear change....both times it will take one minute to click off one mile. Of course your true land speed (while the speedo is showing 60) will be different pre- and post- gear change.

But this is what I think you meant to inquire about: All things being the same as before the gear swap (tire size, tranny, tranny-speedo gear, etc) I'd say that it would speed up the odometer.

Let's use an old ratio of 3.27...why? Because.

This gives us New-gear:Old-gear ratio of 4.10:3.27...roughly 1.25:1 or a 25% increase. That's the amount of driveshaft rotation we need to increase to maintain the same land speed.

In other words, for the tires to be spinning at a true 60mph (post gear swap), the driveshaft needs to spin 25% faster than it did to maintain 60mph before the gear swap....that equates to 75mph showing on the speedo after the gear swap to get 60mph at the rear wheels.

So, 1 mile (pre swap) at 60mph, the odometer would take one minute to click off one mile. Now, let's say you're doing a true land speed of 60 mph, your speedo will say 75 and it will take 52.5 seconds to click off one mile. Effectively speeding up your odometer.

Now...who said you'd never need that algebra crap they taught us in high school?!?!?

- your company's computer guy.

97 Convertible 65 Coupe

The way to correct it is with a SpeedCal.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Tom

1998 GT Coupe 5-spd. Bright Atlantic Blue K&N FIPK, Tri-Ax, 3.73's, FRPP Coated Shorties, SpeedCal, P&P 2K Heads, 2K Intake, Bassani X-Pipe and Cat-Back, Subframe Connectors, JMS Chip, Eagle Alloy Wheels