[MerlinMc]

Previously had an M235i with no LSD. Took delivery of a 2020 M240i in early May, but was unable to get it with the LSD. So, I purchased an M Performance LSD ahead of my vehicle arriving.

The vehicle arrived with a moonroof even though I had explicitly ordered with a moonroof delete. The dealer provided and installed the LSD at no cost as a result of the error on the order.

I am able to compare the driving experience of both my M235i that I sold shortly before the M240i arrived as well as driving my M240i with and without the LSD. This is probably the best single upgrade I’ve made to the many cars I’ve owned over the years. The difference is very noticeable.
Previously, with DSC on, the engine would frequently “bog” down. My driveway is steep and my neighborhood has a fair number of hills so this happened every day to and from work. With DSC off, one could vaporize the rear tires on these hills. Now, with the LSD and DSC on, the car always hooks up with no engine bogging. Even when it’s wet, no problem going up hills or around corners-- DSC doesn’t intervene to cut power to the engine as before. Car now works great with DSC off too.

This is probably old news for those of you with the LSD. The difference is so stark I thought I would share. While the M235i was probably my favorite car of the many I’ve owned, adding the LSD to the M240i has really amplified my enjoyment. Excellent and enjoyable upgrade!

[mcompact]

Glad it worked out for you. Me, I'd make them order another car- I don't want a hole in the roof.

[MerlinMc]

Originally Posted by mcompact

Glad it worked out for you. Me, I'd make them order another car- I don't want a hole in the roof.

I strongly considered that, but had already sold the M235i. So no DD for months.

[XCC Motorsports]

Thanks for sharing your experience on the LSD. I have been on the fence for awhile now, so this helps nudge me along.

[B58togo]

$2500-3000 worth of LSD and install on the house is one hell of a consolation prize for having to keep the car with the sunroof! Most dealerships would have offered you a couple coupons for a free detail. I just got my LSD installed yesterday and am loving it. Re-learning how to drive it though with DSC off. I got in a little hot on a tight right yesterday and snapped the ass around quick.

[CP911]

Big fan of the M Performance LSD here as well. I urge all of you with the LSD installed to exercise extreme caution when driving with DSC OFF. It's dangerous. Without the LSD, you still have one wheel that isn't spinning and will provide traction to keep the car on the road. However, with the LSD installed, all bets are off once you break traction with both rear wheels receiving torque and spinning simultaneously. On wet roads, off-camber roads, etc. the rear can snap around very quickly without giving you much warning or a chance to react. I guess my point is, save DSC OFF for the track or when you aren't around ANY traffic. Besides, the LSD itself provides enough traction that DSC shouldn't be intervening much to begin with. Keeping DSC ON or at the very least using Dynamic Traction Control (DSC only partially disabled) should allow you to maximize the benefits of the LSD's enhanced grip and forward propulsion, while still providing some type of safety net to keep the car from snapping around and potentially killing someone out there. Just my 2 cents. Keep it safe and enjoy!

[MerlinMc]

Originally Posted by CP911

Big fan of the M Performance LSD here as well. I urge all of you with the LSD installed to exercise extreme caution when driving with DSC OFF. It's dangerous. Without the LSD, you still have one wheel that isn't spinning and will provide traction to keep the car on the road. However, with the LSD installed, all bets are off once you break traction with both rear wheels receiving torque and spinning simultaneously. On wet roads, off-camber roads, etc. the rear can snap around very quickly without giving you much warning or a chance to react. I guess my point is, save DSC OFF for the track or when you aren't around ANY traffic. Besides, the LSD itself provides enough traction that DSC shouldn't be intervening much to begin with. Keeping DSC ON or at the very least using Dynamic Traction Control (DSC only partially disabled) should allow you to maximize the benefits of the LSD's enhanced grip and forward propulsion, while still providing some type of safety net to keep the car from snapping around and potentially killing someone out there. Just my 2 cents. Keep it safe and enjoy!

Great advice. I have been using mine almost exclusively with the DSC on. It intervenes much less than before.

[msej449]

My feedback is that the LSD is great but it doesn't mean you should turn DSC=Off. And that you have to understand just what it is you're disabling when you turn it off on public roads.

Coming away from an M140i-based wet-weather driver training course at a race circuit last year, I realised that in many ways, DSC is the final 'failsafe insurance' for most drivers. Training to handle the car on a skidpan so as to avoid oversteer spins was all done in SPORT+/DSC=Off.

My LSD certainly makes intervention by DSC less likely, but when DSC does intervene it's still for a very good reason: generally because I've got my gear/throttle/steering badly wrong. And so on a public road, the intervention is still welcome.

As mentioned, on a track, yes, DSC may make interventions that are counter-productive, and warrants being disabled. But on public roads, I'm not sure what you're gaining by disabling it. But I'm happy to hear feedback to the contrary.

[Heitzer]

Had the LSD for three years and have zero regret. Getting up snowy driveways also got easier in addition to the performance advantages.

If you also change the final drive ratio (manual cars) you get more power at the same. I have 12 percent more thrust through the rev range.
https://www.2addicts.com/forums/show....php?t=1113986

I didn't see the need to tune the engine. For me the mods give the most smiles for a daily driver. More than all those over engineered cars you can buy for lots of money

[MassNerd]

Originally Posted by CP911

Big fan of the M Performance LSD here as well. I urge all of you with the LSD installed to exercise extreme caution when driving with DSC OFF. It's dangerous. Without the LSD, you still have one wheel that isn't spinning and will provide traction to keep the car on the road. However, with the LSD installed, all bets are off once you break traction with both rear wheels receiving torque and spinning simultaneously. On wet roads, off-camber roads, etc. the rear can snap around very quickly... snipped

This could explain my observations at the skidpad. Two moderately experienced drivers, both first time at the skidpad with their new cars. The M235i with no LSD quickly was able to power oversteer in control around the pad. The other guy in his M2 Comp was really struggling at first and did spin the car quite a bit. Both cars on sticky PSSs or PS4S. Granted there's a power difference in those cars too, but maybe the LSD had something to do with it. I don't think it was the drivers because I know the M2 Comp driver is capable.

[XutvJet]

This review pretty much matches my experience with installing the LSD after two full years of ownership without out it. The difference is staggering. I have a 6MT and prior to the LSD, I couldn't go full throttle in 1st without destroying the PSS tires. I often could punch the gas in 2nd from a 3000rpm roll and light up the tires too. This was in Sport+ and DSC Off. With the LSD and assuming it's dry and the temps are above 65 or so, I can punch it in 1st with little to no spin. I don't have much issue with punching it from a 2nd gear roll either. It usually hooks and goes. The car almost feels slower because there's way less spinning drama. I can launch far harder too, especially with my new PS4S tires. I can now launch at 3,500-4,000rpms with a bit of clutch slip and it launches surprising well for a torquey RWD car and nearly as hard as my 2012 WRX could. Prior to the LSD, it was just a lot of spin and wasted momentum.

What really impresses me is even when the tires are spinning with the LSD, there is far less forward progress lost. In a turn and during aggressive driving, when you're on, steady, or off the throttle, the LSD does wonders for the rear axle. Add throttle and the nose actually pulls inwards towards the turn. It's almost opposite of what it did prior to the LSD. Under braking, the LSD is working for you too as it has 10% lock under braking too.

Even with the rear sliding, the rear end is far more controllable with the wheel and throttle. It slides gracefully rather than the erratic rocking motion it had in DSC Off and especially Sport+. I've had other cars with LSDs and this clutch-based setup is light years ahead of those. It feels very robust and like you've added 500lbs over the rear axle.

Lastly, I don't find driving the car hard in DSC Off to be frightening or dangerous either. Perhaps it because I formerly owned and drove 90s pony cars with lots of torque and no nannies from the start. I think the younger generation has primary owned cars with nannies so they tend to overdrive the cars and when the nannies are off they pay for it.


My LSD review: https://www.2addicts.com/forums/show....php?t=1493261

[Poochie]

The LSD in the 235i:

[albertw]

Originally Posted by XutvJet

This review pretty much matches my experience with installing the LSD after two full years of ownership without out it. The difference is staggering. I have a 6MT and prior to the LSD, I couldn't go full throttle in 1st without destroying the PSS tires. I often could punch the gas in 2nd from a 3000rpm roll and light up the tires too. This was in Sport+ and DSC Off. With the LSD and assuming it's dry and the temps are above 65 or so, I can punch it in 1st with little to no spin. I don't have much issue with punching it from a 2nd gear roll either. It usually hooks and goes. The car almost feels slower because there's way less spinning drama. I can launch far harder too, especially with my new PS4S tires. I can now launch at 3,500-4,000rpms with a bit of clutch slip and it launches surprising well for a torquey RWD car and nearly as hard as my 2012 WRX could. Prior to the LSD, it was just a lot of spin and wasted momentum.

What really impresses me is even when the tires are spinning with the LSD, there is far less forward progress lost. In a turn and during aggressive driving, when you're on, steady, or off the throttle, the LSD does wonders for the rear axle. Add throttle and the nose actually pulls inwards towards the turn. It's almost opposite of what it did prior to the LSD. Under braking, the LSD is working for you too as it has 10% lock under braking too.

Even with the rear sliding, the rear end is far more controllable with the wheel and throttle. It slides gracefully rather than the erratic rocking motion it had in DSC Off and especially Sport+. I've had other cars with LSDs and this clutch-based setup is light years ahead of those. It feels very robust and like you've added 500lbs over the rear axle.

As someone who has trouble understanding the fascination with the LSD, this post finally provides some real information. A comment and some questions.

I've never used full throttle in first gear, and never will. If I want to be a hooligan, I prefer doing it on my bike. So the first paragraph is irrelevant to me. The only reason I want the power of the 240 is for backroad passes, which usually start at 40+ mph.

I don't understand "Add throttle and the nose actually pulls inwards towards the turn." Assuming you're not already sliding but just cornering hard, normally adding throttle makes the car run wider, and lessening the throttle transfers weight to the front so the car turns into the corner. My previous car (Corvette Z06) had an LSD and did this, as did the Boxster I took for an extended test drive. I don't have a lot of experience with many different cars, but I don't see how an LSD can affect this behavior. There's no wheelspin involved.

I don't understand how the LSD can help in braking. The ABS can't be turned off and if you push the pedal hard enough it will keep each wheel at the limit of traction. How can the LSD add anything?

Regarding the oversteer behavior, I wonder if you've got your memories backwards. For the sort of sliding I'm willing to do on the street when I can see through the whole corner and there's no traffic, I find stepping the rear out a foot or two easy and very predictable in Sport+. As a previous post stated, that's because only one wheel is spinning and the outside rear is mainly sliding, so you control the slide by varying the amount of traction the inner wheel uses for spinning vs turning. It's in DCS OFF, where the eLSD turns on, that the sliding behavior gets strange for me. It's not always on, like a mechanical LSD, and I found it hard to predict so I stopped using it. Maybe I could have gotten used to it with a lot of practice, but I also like the backup of the nannies in Sport+.

[aaaaah]

Originally Posted by albertw

I don't understand how the LSD can help in braking. The ABS can't be turned off and if you push the pedal hard enough it will keep each wheel at the limit of traction. How can the LSD add anything?

By partially locking the rear axles together, when you are braking you are less likely to lock up one of the rears as it is still transferring torque the whole time. It's just the reverse of spinning a single wheel vs both wheels under acceleration.

[dradernh]

I wouldn't have purchased this car if an LSD hadn't been available. It's a critical component in a street/track car (my use), so one was installed at 1,972 miles.

Even though a Wavetrac was chosen (on the advice of Dan at DiffsOnline, based upon how the car would be used), the M Performance LSD would have been acceptable as well.

Originally Posted by albertw

I don't understand how the LSD can help in braking.

Depending upon the design and implementation of the diff, the car may be better at maintaining stability, especially on uneven surfaces.

An extreme example would be when you're in a heavy-braking zone on a surface that's somewhat rippled or otherwise lacks the traction you'd have on a smooth, flat surface. This could be during a panic stop, entering a high-speed braking zone on a track, or when going much too fast into a corner on the street.

Those are circumstances where the rear-end can sit up and wiggle around a bit. That can be disconcerting for a driver who doesn't know what's happening, and therefore a potential danger. The car's spring rates and how sharply the driver applies full-force braking also can have an effect upon how much the car's rear end sits up and moves around.

My take is that you're unlikely to notice an LSD's locking behavior under braking unless you're working the car very hard and/or the surface is especially bumpy or loose.

[Hekler]

Originally Posted by dradernh

I wouldn't have purchased this car if an LSD hadn't been available. It's a critical component in a street/track car (my use), so one was installed at 1,972 miles.

Even though a Wavetrac was chosen (on the advice of Dan at DiffsOnline, based upon how the car would be used), the M Performance LSD would have been acceptable as well.

How much are either one of these LSD installed complete?

[MarcoZandrini]

Originally Posted by B58togo

$2500-3000 worth of LSD and install on the house is one hell of a consolation prize for having to keep the car with the sunroof! Most dealerships would have offered you a couple coupons for a free detail. I just got my LSD installed yesterday and am loving it. Re-learning how to drive it though with DSC off. I got in a little hot on a tight right yesterday and snapped the ass around quick.

My dealer refunded me $500 when my custom ordered M340i was delivered with a moonroof. I ordered the car with the moonroof delete as I intended to track the car. Now I have to lower the seat and cock my head a bit.

[dradernh]

Originally Posted by Hekler

How much are either one of these LSD installed complete?

Mine was $2,424.41 all-in.

However, the diff was discounted (don't recall how much - maybe 10%?). Also, it got installed when the rear subframe was already out of the car to install aluminum subframe bushings. Based upon what the shop told me, I assigned most of the labor to the subframe bushing install (it was $600 for both).

My build sheet shows the following:



Others have shared their costs in this forum, but I think you'd probably be looking at $2,500 to $3,000 installed for an M Performance diff (P#s: 33108659987 (manual); 33108659989 (auto)) or a Wavetrac like I got.

DiffsOnline has a page that will give you an idea of pricing for a wide variety of non-M Performance diffs built to spec for everything from basic street driving to serious racing. You can see more here: https://diffsonline.com/bmw-f22-m240...l#.XRkw6uhJG70.

[Hekler]

Thanks for the detailed response. I think I would have to drive one with the LSD before I could spend that much. I will continue to gather information and see what happens....

[XutvJet]

Originally Posted by albertw

I've never used full throttle in first gear, and never will. If I want to be a hooligan, I prefer doing it on my bike. So the first paragraph is irrelevant to me. The only reason I want the power of the 240 is for backroad passes, which usually start at 40+ mph.

It's not even full throttle. I'm mostly talking about turning out into traffic and you need to use 50-75% throttle. I can hit it in 1st with no worries of the tires spinning or the nannies intervening or having to short shift into 2nd then hammering it. It's also really nice to know that I can go full throttle to redline in 1st with not much worry of wheelspin. It has nothing to do with being hooligan.

I don't understand "Add throttle and the nose actually pulls inwards towards the turn." Assuming you're not already sliding but just cornering hard, normally adding throttle makes the car run wider, and lessening the throttle transfers weight to the front so the car turns into the corner. My previous car (Corvette Z06) had an LSD and did this, as did the Boxster I took for an extended test drive. I don't have a lot of experience with many different cars, but I don't see how an LSD can affect this behavior. There's no wheelspin involved.

Pretty simple really. Hit it fairly hard in a sweeping turn in 2nd and without the LSD, the inside tire will usually spin and the backend gets light and loose and car feels like it wants to slide or drift away from the turn. With the LSD, a lot more power is transferred the outside tire. This then pushes the rear outside of the car into the turn thus the chassis plants and helps the car go where you want it to go all the while being WAY more stable. The MP LSD is a very high quality piece and setup very nicely for hard street driving and moderate track use. You know it's there and can really feel it.

Regarding the oversteer behavior, I wonder if you've got your memories backwards. For the sort of sliding I'm willing to do on the street when I can see through the whole corner and there's no traffic, I find stepping the rear out a foot or two easy and very predictable in Sport+. As a previous post stated, that's because only one wheel is spinning and the outside rear is mainly sliding, so you control the slide by varying the amount of traction the inner wheel uses for spinning vs turning. It's in DCS OFF, where the eLSD turns on, that the sliding behavior gets strange for me. It's not always on, like a mechanical LSD, and I found it hard to predict so I stopped using it. Maybe I could have gotten used to it with a lot of practice, but I also like the backup of the nannies in Sport+.

I don't know what to tell you here other than go drive a 2 series with an LSD. When the backend steps out in Sport+ or DSC Off, it is far easier to control under throttle. It slides with grace and has none of the abruptness and wonkiness it did without the LSD.

The LSD was the single best performance mod I've done to the car. I have way more confidence and the car feels much more planted. As I've said before, it is like having two 250lb guys sitting over the rear axle but without the acceleration weight penalty. I've had LSDs in other cars but they were junk compared to this marvel.

[CP911]

Originally Posted by MassNerd

This could explain my observations at the skidpad. Two moderately experienced drivers, both first time at the skidpad with their new cars. The M235i with no LSD quickly was able to power oversteer in control around the pad. The other guy in his M2 Comp was really struggling at first and did spin the car quite a bit. Both cars on sticky PSSs or PS4S. Granted there's a power difference in those cars too, but maybe the LSD had something to do with it. I don't think it was the drivers because I know the M2 Comp driver is capable.

That sounds a bit off to me. Do you know what driving modes both cars were in? The M235i/M240i without LSD does not power oversteer very well and certainly not "in control." Perhaps with the eLSD active (when DSC is fully off and the brake-simulated LSD becomes active), it can, although I've never tried this myself and have heard/read that it is not very predictable in sustained oversteer/drift situations. However, in any other driving mode, the lack of LSD will cause the inside tire to spin and chatter, while the outside tire basically just drags along. There is hardly any forward propulsion when this happens, so the rear end just steps out briefly and snaps back violently as soon as the throttle is cut either intentionally or when DSC cuts it for you. I can't imagine anyone sustaining a controlled drift in a M235i without LSD.

My guess is that the M2C owner just had a bigger beast to tame and struggled a bit. The wider tires will have a less progressive loss of traction, so that combined with more power can create unpredictable/sudden oversteer situations.

[albertw]

Originally Posted by XutvJet

It's not even full throttle. I'm mostly talking about turning out into traffic and you need to use 50-75% throttle. I can hit it in 1st with no worries of the tires spinning or the nannies intervening or having to short shift into 2nd then hammering it. It's also really nice to know that I can go full throttle to redline in 1st with not much worry of wheelspin. It has nothing to do with being hooligan.

Wow. If you need that much throttle to fit into traffic you must be scaring the hell out of the oncoming driver. Sounds like hooliganism to me.