kgkern01

iTrader: (10)

So I'm thinking of doing a rear gear swap on my TA. Its got mild EB Ported heads, custom LE cam, shift point 6300 (stock short block), 315 Toyo R888's, and is mostly an autox and nice weather street car, with maybe 1 or 2 trips to the local 1/8 mi track per year just for fun.

I still have the stock 3.42's in now, and am considering moving up to either 3.73's or maybe even 3.90's if not too drastic. With the .62 6th gear, it doesn't cruise as low in the RPM's as it used to with the stock MM6 trans, so I don't want to go too radical on the ratio. However it is an E85 only car, so gas mileage was never a real concern with this car.

LeanPocket

iTrader: (6)

since ur m6 go 4.10.. trust me u won't look back

kinglt-1

iTrader: (26)

agreed!

kgkern01

iTrader: (10)

The M29 is geared different than the typical MM6:
MM6: 2.66/1.78/1.30/1/.74/.5
M29: 2.97/2.07/1.43/1/.80/.62

So if I went to 4.10's with my trans it would be like having the following rear ratios in a MM6 (per gear): 4.57/4.77/4.51/4.10/4.43/5.08 that's a little too high gearing IMO.

For reference, comparative ratios for M29 vs MM6:
Rear 1/2/3/4/5/6
3.42 3.82 3.98 3.76 3.42 3.69 4.24
3.73 4.16 4.34 4.10 3.73 4.03 4.62
3.90 4.35 4.53 4.29 3.90 4.21 4.84

This is why I was thinking of going from 3.42 to 3.73 because it would be similar to having 4.10's in an MM6 car, and although not a big change from current, would still give about 9% difference or 14% for 3.90's...