Does adding an M3 LSD cause issues?

[Fried_Chicken]

Recent circumstances have convinced me of the value of an LSD. I’m a little bit hesitant, as my understanding is that an open Diff is nicer than an LSD, as an LSD might cause issues such as crabbing or otherwise, and may need to on occasion be unwound or otherwise? Does it eat tires with normal use (meaning not drifting or anything)

I don’t want to sacrifice the comfortable, reliable, and generally mild-tempered nature of the car for the rare occasion that I use the LSD.

[Reasoned1]

I’m curious what the convincing circumstances were. Especially given the “mild-mannered” nature with which you wish to drive, I don’t see much of a point in spending the money. That said, a limited-slip differential presents none of the issues you mention. I installed an MFactory helical LSD, and it is without a single issue—no clunks, no noise... just a grippy 10% torque increase (3.38 versus 3.07) at the wheels in all gears that, also, significantly reduced the intrusiveness of the traction control. Any car with limited slip is better than a car without, but the question is whether the improvement is leveraged and worth the money.

[t.er]

Yeah, if having an LSD compromised NVH beyond acceptable levels of a DD then not many road cars would have them. It's possible you may feel/hear it if you get an aftermarket diff geared (...haha) towards racing, perhaps you spec a very steep ramp angle for early lockup. But there are many streetable alternatives from companies like MFactory or diffsonline

[Fried_Chicken]

I’m curious what the convincing circumstances were.

http://www.zhpmafia.com/forums/showthread.php?23491-WWWWWHHHHEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE

It depends if I can get an M3 LSD for cheap. I’d only want the BMW OEM one, nothing aftermarket.

[t.er]

http://www.zhpmafia.com/forums/showthread.php?23491-WWWWWHHHHEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE

It depends if I can get an M3 LSD for cheap. I’d only want the BMW OEM one, nothing aftermarket.

I'd definitely consider an aftermarket one. Reason is because you need the entire subframe assembly from the M3, along with the driveshaft I believe. That will get you the M3 LSD for about $1000 but it'll have some miles on it, and may not have as much "LS" part of LSD as a new one. It's about the same cost for the LSD from MFactory but it'll be new, you just have to swap the cores out.

And lastly with the 3.62 final drive ratio, it's not going to be very pleasant if you do a lot of highway driving

[Reasoned1]

If you do go aftermarket (at least with MFactory), it’s also possible to purchase and swap out the entire pumpkin assembly.

[Vas]

+1 for the MFactory helical LSD.

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[Fried_Chicken]

Does the MFactory remain the same final drive ratio? Does it “feel” the same? Does it introduce noise? Crabbing? Anything like that?

[sna77]

I have a Diffslonlie LSD... Swapped the gear ratio for 3.38. Did this in my last ZHP as well. So worth it.

https://diffsonline.com/bmw-e46-323-325-328-330-inc-xi-custom-performance-differentials.html#.YARSb-hKg-U

[Fried_Chicken]

What's the stock ratio?

[sna77]

What's the stock ratio?

3.07 for mt


http://www.zhpmafia.com/forums/showthread.php?8400-Have-rear-differential-ratio-question-and-seek-clarification-on-my-convertible