3.23 in a M10 ??

[jeffnhiscars]

I bought a no-diff subframe to do an eventual drum>disc swap and since my stock (according to my owners manual & tag) 3.46 open weeps from the output flanges, I think about diff options. Everyone raves about 3.73 and 4.10 but honestly I'm thinking in the other direction.

Sure its a stock M10, but with a K&N, header, full Ansa cat delete, 5 spd & 8lb flywheel, it breaths and revs quite nicely. I run thru 1st & 2nd VERY quickly and at 70MPH Im at 3000 rpm's so Im leaning more to a 3.23. Quieter and more fuel efficient on the hwy, will IMHO take better advantage of 1st & 2nd and if the engine is ever not happy..well thats what 5 gears are for.

Make sense or recipe for misery ?

[rogue38]

I think you will lose a bunch of acceleration, but definately gain MPG.

I have been toying with the same notion of but keeping another rearend if i decide to take mine to the track. My daily commute I don't have the need for the acceleration. Nor do I have the need to attract attention with the high revs. I am not looing forward to a road trips doing near 80 on the interstate and the revs around 3400, that will surly equal poor MPG.

My daily commuting avg is around 26mpg with the M20 and the 3.73 gears.

[Wanganstyle]

replace the seals? much less money / easier than buying an entire diff and can be done with diff in car still.

The difference between 3.23 and 3.46 is probably not enough to be worth the trouble, ratios of: 3.15/3.07/29.3 would be more ideal of a drop down from 3.46.

I bought a no-diff subframe to do an eventual drum>disc swap and since my stock (according to my owners manual & tag) 3.46 open weeps from the output flanges, I think about diff options. Everyone raves about 3.73 and 4.10 but honestly I'm thinking in the other direction.

Sure its a stock M10, but with a K&N, header, full Ansa cat delete, 5 spd & 8lb flywheel, it breaths and revs quite nicely. I run thru 1st & 2nd VERY quickly and at 70MPH Im at 3000 rpm's so Im leaning more to a 3.23. Quieter and more fuel efficient on the hwy, will IMHO take better advantage of 1st & 2nd and if the engine is ever not happy..well thats what 5 gears are for.

Make sense or recipe for misery ?

[jeffnhiscars]

Thanks for the input guys.

Im getting 23\28 mpg so thats not a big priority. Its more about driveability and fun (and being a compulsive modder). Again, I cant compete on torque with an M20 so it involves optimizing use of the gear box which is what appeals to us M10 guys anyway, right ?

I also agree the 3.23 is not that big a difference but thats part of the appeal. Remember, I'll be doing a sub frame swap that will require me moving my 3.46 over so it will be out anyway and I just keep thinking about the noise at 80 with a 3.46.

My sense is that I rev so fast now in 1st & 2nd that taller gears may actually improve acceleration. Im just thinking its a tweak in the right direction. Time will tell.

[a3ternus]

I have a 4.27 LSD on my M10.
Life is miserable.
Go with the 3.23 and save money!
N.

[jeffnhiscars]

I have a 4.27 LSD on my M10.
Life is miserable.
Go with the 3.23 and save money!
N.

I can imagine !!

I'm pretty confident a 3.23 would be a good fit for my car and if its isn't, its no big deal to pop my 3.46 back in.

Now I just have to find out if a small case 3.23 exists or what the weight difference is if I go medium.