The only problem is the cost:
-Ford 8.8 diff
-Axles
-Driveshaft
-Diff mount
-Refab exhaust to clear pumpkin
-fabricate transmission mount

 

This is from Mazdaspeed Motorsports Development? I can't find it in the competition parts catalog, they have a zillion other R&P ratios (5.12:1, anyone?) but no 3.63.

--Ian

 

Yes

 

its stock. not in comp parts

 

Where in stock parts? Those parts are all sorted by year/model, and the oldest 626 they have is 1986.

--Ian

 

I need to find a dealer around here for diff swapping. Can anyone explain to me why a 99 5 speed and a 3.63 is fail? Here pretty soon going to be doing a 45min commute each way on freeway alone for school and really want to lower the rpm's for highway use. Sitting at 4k in 5th now at about 80. Would love a 6spd but not in the budget, yet. Or would the 5spd w/3.63 make 1st gear tall as hell?

EDIT: Also is there a chart anywhere with what fits, ratios, and what cars they come from with years? Been searching but apparently my google skill need updating

 

FM has a gearing chart on their site somewhere that shows speed/gear. That should answer questions. Running the 5spd with the 3.63 would just put a damper on acceleration numbers- you'd still be able to get the car rolling. Definitely feasible given your commute if you can stand a slower car, but IMO with boost it's not a big deal.

 

I've driven a car with this, with a 260whp supercharger, and the gears are miserably long. It could reasonably take 15-minutes to wind-out 3rd in a stock car.

 

Don't forget that your tach is slow, so it's actually 4200rpm and you're open-loop, getting shitty MPG.

Johnwag and I are building them now, maybe you could send your pumpkin to us. Oh and by "Johnwag and I" I mean "john builds them while I drink and phonewhore".

 

I don't doubt that (specifically the spread on 2 & 3 - see attached), but his concern seems to be the rpm (or enduring it) on a long commute. That gear will definitely change the rpm in fifth at his speed. The other (preferred) option is swap in the rx7 5th gear- but I have no idea the cost difference.

 

Here's the FM link you guys were looking for: http://www.flyinmiata.com/tech/gearing.php

 

Are they all like that? My tach is fast, but i've got a late NB, don't know if that makes a difference... 7000rpm dyno pull was showing 7500-7600 on the stock tach.

 

Part number MA02-27-110, jeez I bought one a few years ago from mazda, was like $300.

 

Thanks to Helicopter Ben....

 

lol @ weak dollar

 

Guess I'll be stock pilling drivetrain parts in the garage. By building them you guys just need a carrier and the gear and you do the work. I'm down, don't trust myself enough to set the lash. Need to sell my 97 so I can afford to be baller. Used 6spd and new r&p here I come. Also curious why the tachometer is slow? Just always reads a percentage low or just lags behind on rev. Any cheap fix? It seams like no car has an accurate tachometer. Guess my question is should a autometer tach possibly solve it or is the tachometer pickup just scetchy. Or is it just the nature of the beast

 

If you've got a standalone, just don't worry about it. Just know where your true fuel cut is, and stop there.

I'm guessing on my tach, fuel cut will be showing somewhere around 8k, because it's rather optimistic.