[XutvJet]

It’s probably old news for many, but I wanted to share my experience with the MPerformance LSD. After over 2 years of ownership, I added the MPerformance LSD on Monday. I’m the type that likes to learn a car’s characteristics fully before adding mods as it really helps me understand pro/cons of the mod. Admittedly, I’ve wasted a ton of money over the past 20 years on overhyped, ill-fitting, and compromising mods that do more harm than good and I’m not one to hold back and remove a mod immediately if it’s crap.

I'm still breaking it in the LSD, but HOLY HELL, what a difference. It feels like I've added a ton more traction on the back axle. It feels like the OEM MPSS tires are substantially stickier out back. It's quite astonishing the difference, even in the most normal of driving. On a sweeping turn, transitioning from off throttle to moderate throttle instantly results in the car/steering wheel turning harder and harder into the turn. I’ve had other cars with lower quality LSDs, but I've never felt an LSD behave quite like this. The car just feels a ton more stable. It's awesome.

To break in the LSD, the dealer and other sources said to go out to a parking lot and do about 20 idle rolling, near steering wheel lock Figure 8s followed by 20 idle rolling near steering wheel lock circles in each direction. BMW says to drive moderately for the first 500 miles and to avoid hard shifting or situations that could cause axle tramp.

My dealer price matched the best online offer I found for $1,950. It was 3.5 hours to install which is the BMW book time as confirmed by internet searches for what others said labor was at BMW. The tech installing the diff was adamant that he check the fluid level in the diff before install because it had been his experience that some BMW diffs are underfilled from the factory and it’s a pain to check the level and add fluid after the diff is installed. He found the diff slightly underfilled and added about ¾ pint of BMW LSD-spec fluid. All in, it was about $2,700 for the LSD, labor, fluid, and tax. Yeah, crazy expensive.

The LSD is a 3 clutch lock-up with 30% lock-up on acceleration and 9% on deceleration. Pretty ideal for street driving and moderate track use. The LSD is built for BMW by Drexler, an Australian company known for making some of the best LSDs for racing. It's a very high quality piece.

If you're a car guy and really in tune with the way a car feels and are comfortable pushing the car a bit on the street (when it's safe of course) and you plan on tracking/auto-x, it's a great mod. For many, they probably won't feel the difference or really use it. Even at 4/10ths driving, I can tell it's there and working it's magic. The car is wicked in DSC Off now. The car just feels more robust and substantial. It’s hard to explain. Perhaps the lighter wallet is also affecting my brain.