i have an 88 5speed w/ a 4.10 diff ratio and i was looking for something with a lower ratio. I found a 4.33 but want to go even bigger yet, got any ideas

 

there are companies that sell rearend gears for club racers. they aren't cheap though.

 

See this page....http://members.aol.com/solomiata/Drivetrain.html

Anything that fits a Miata diff should bolt to your '88 diff AFAIK. The ring gear anyway. The pinion is another story...

 

http://www.iscracing.net/2nd_Gen_Parts.htm

They'll make you a shorter diff, but it'll cost you.

 

The ring gear for a miata is the wrong size for an FC diff. All you can use from a miata diff is the actuall guts of the diff, which is useless for changing the final drive. You can get a shorter final drive through mazdatrix. I wouldn't recommend doing, though, if you ever drive it on the highway. It will slaughter your gas milage.

 

No it won't. I've got a 0.807 5th gear (the stock 5th is 0.691), which is much more of a change than going to a 4.3:1 rear end from a 4.1:1, and I can still get about 24mpg on the highway going up and down hills, cruising at 80mph with the windows down.

 

When I swapped to a 4.3 there was also a 4.6 available from Mazda, but my dealer said it was only available to factory acknowledged teams. Don't know if it was BS or not

 

You are correct sir...I had forgotten that the ring gear was a different size. I was thinking of the guts.

 

How much are you willing to spend?
1G RX-7 gear ratios can be stuffed into your FC housing, but it's a lot of work and time.
Are you willing to pay for it?


-Ted