Easy Taller Diff Options for '93 525ia w/current 4.10?

[RobPatt]

- Want more pep from the beauty.
- Engine mods too costly/involved
- Could do auto/manual tranny swap, but auto still good, too costly/involved...
- Already tuned/maintained, etc and have EAT....
- So next to losing weight, which spoils the car...
- Thinking taller diff is a cheapest and quickest mod....
- What's a bolt in swap? where to get one?
Any info appreciated! Thanks, Rob sends.....

[Rigmaster]

About your only option is a 4.27 from a 535iA. They are sort of hard to find, but they are out there.


Bret.

[632 Regal]

isnt there a 4:56? dude your ratio is pretty much tops, tome to make some torque with the engine.

[Kalevera]

Well, for starters, we need to get the terminology correct. A lot of people have been getting this mixed up recently. A taller rear end gives a higher theroretical maximum speed, while a shorter rear end gives better acceleration around town, only at the expense of RPMs when a > 15% change in ratios is made.

Read this: http://www.automedia.com/Differential/Gears/The/Optimum/Choice/pht20011201rg/1

Or, you can read about it on our web site:

http://www.koalamotorsport.com/diffs.asp


To do it correctly, you're going to spend as much on the rear end as you would on any of those other upgrades. Frankly, I think the money's best spent on engine modifications or dumping the auto, but that's all dependent on what you want. A quality rear end will cost $1500.

The 4.27 is a good idea, but given that the M50/tu is what it is, I'm not sure you'd get a lot of bang for the buck.

best, whit

[RobPatt]

.... guess that's the great thing about this forum....

so I should have said shorter, got it, thanks.....
and surprised, I was hoping for $500 or so could swap to a shorter diff....
no idea $1500 was more like it...wow!

well for $1500 a 4.27 isn't much difference......
and not sure if there's anything shorter (thus the post)....

so how to make more torque from the M50TU?

looks like w/my criteria (less than $1500) I'm out of Schlitz... ? or not?

[mholbrook]

You can probably buy a 4.27 for around $150 - $300 depending on your source. Then the R$R will cost about 3 hours from the shop. If you can do the swap yourself, it might be worth it to have LSD and the maybe 3% lower ratio.