E12 M535i LSD Internals in An E21 Casing

[Kogando]

I sell reinforced e21 lsd-differentials since they originally cannot withstand more than 150hp.

Ahem, you sure about that? What do you base that fact on?

It's based on the fact that I've had a lot of broken lsd's from customers used on e21's with more than 150bhp. And of course you can have luck, or if you drive it with caution it can withstand a bit more. But the 168mm differentials (e21) are relatively weak.

[E21meister]

I sell reinforced e21 lsd-differentials since they originally cannot withstand more than 150hp.

Ahem, you sure about that? What do you base that fact on?

It's based on the fact that I've had a lot of broken lsd's from customers used on e21's with more than 150bhp. And of course you can have luck, or if you drive it with caution it can withstand a bit more. But the 168mm differentials (e21) are relatively weak.

Remember this: E21 LSDs and driveshafts are at least 29 years old, so of course should be rebuilt as a matter of course. But, the problem is people still expect them to do now exactly what they did when new, then wonder why they blow up! They wouldn't think twice about rebuilding an engine but don't apply the same philosophy to running gear? I battered the fook out of my LSD for about 10 years on two cars and it never grumbled; I doubt that's luck, more like regular Castrol Hypoy LS 90 changes. It'll be fully refurbished before it goes in my new car of course.
Yeah, an M535i diff is stronger but any diff will get mullered if you keep abusing it.

[nas80]

I have a quaife fitted into stock casing, lifetime warranty, and won't wear out.

By the time you done all the machine work, rebuilt the clutch type lsd you will end up paying the same?

The small case diff can handle 280lbs/ft atw, as meister says maintenance and treatment is key.

[E21meister]

I have a quaife fitted into stock casing, lifetime warranty, and won't wear out.

Will have to pick your brains at a later date on that (is the one in question the QDF4N for a 2002?), as if I put a Quaife into a standard casing, which might be handy to handle to torque of a 3.0 M20 at a later date. And I'd still have a standard LSD to sell...

[Kogando]

I have a quaife fitted into stock casing, lifetime warranty, and won't wear out.

By the time you done all the machine work, rebuilt the clutch type lsd you will end up paying the same?

The small case diff can handle 280lbs/ft atw, as meister says maintenance and treatment is key.

Of course you can use a Quaife instead, and regarding maintainance this is the best option. But I would not go for Quaife since it's a 1-way differential and thus doesn't lock when decelerating. For safety and comfort Quaife is the way to go, but when you drive your BMW on the track or like to play with it you really are better off with a ZF 2-way or 1.5-way LSD. This is the reason Quaife isn't that popular in the motorsport business. Not to mention drifting, where a Quaife is pretty useless.

But it's a fine piece of technique!

[nas80]

My car hasn't been built for the track. Its a fast road thing. I can drift out of corners and donuts fine, it is ,a one way but tbh that's all you need on the road.

I can see your point about racing, but if I wanted a track car and it had to be an old bmw, I'd buy an e30 lol.