Best LSD

[bignico_05]

Regardless of the price, what's the best lsd we could buy for our car to put the power down?

[MightyMouseTech]

Depends on how you define "best".

Just like tires, "best" is different for everyone.

[bignico_05]

Originally Posted by MightyMouseTech

Depends on how you define "best".

Just like tires, "best" is different for everyone.

Good point... I guess best performing and everyday durability.

[brusk]

Depends on what you plan on doing with it. Tracking it, just driving on the street, drag racings, drifting etc. each will work a little better in certain situations.

[bignico_05]

Originally Posted by brusk

Depends on what you plan on doing with it. Tracking it, just driving on the street, drag racings, drifting etc. each will work a little better in certain situations.

Basically the one that could do all those things with no compromise.

[c_ozanich]

Originally Posted by bignico_05

Basically the one that could do all those things with no compromise.

to reference the tire theory above - a winter tire is good in snow, a summer tire is good on dry pavement, a track tire is good for the specific track conditions (grip/drift/etc). An all season tire does everything at 75% efficiency of the all winter or the all summer.

The question of usage was posed bc different goals require different answers here. If you are going to track it, what type of track events? If you are going to beat on it in the streets, reliability would be a higher priority. There are many variables to take into consideration, you will never have a definitive answer because of the sole basis that this is an opinion question.

If you are looking into one, I would research what particular LSD you need for your application/driving plans; then ask what company makes a reliable product that has been proven.

[bignico_05]

Originally Posted by c_ozanich

to reference the tire theory above - a winter tire is good in snow, a summer tire is good on dry pavement, a track tire is good for the specific track conditions (grip/drift/etc). An all season tire does everything at 75% efficiency of the all winter or the all summer.

The question of usage was posed bc different goals require different answers here. If you are going to track it, what type of track events? If you are going to beat on it in the streets, reliability would be a higher priority. There are many variables to take into consideration, you will never have a definitive answer because of the sole basis that this is an opinion question.

If you are looking into one, I would research what particular LSD you need for your application/driving plans; then ask what company makes a reliable product that has been proven.

I've already done some research but just end up confusing myself even more. So I just want some advice/opinions of what people thing is the best lsd option. I'm looking for an lsd that will be able to put a significant amount of power down and be extremely reliable. No hardcore tracking events nor any hard launches but occasional spirited driving and few laps around a track.

[MightyMouseTech]

Sounds like my situation.

The car is our daily driver, including heavy Canadian winter. Plus, do some teaching up at our local track.

Will be installing the Quaife sport diff. Complete brand new unit, and comes with a better 3.48 FD for a 14% improvement in torque to the wheels. Usually cruise on the highway at 125 km/hr so don't really care about the decrease in top speed.

[c_ozanich]

Originally Posted by bignico_05

I've already done some research but just end up confusing myself even more. So I just want some advice/opinions of what people thing is the best lsd option. I'm looking for an lsd that will be able to put a significant amount of power down and be extremely reliable. No hardcore tracking events nor any hard launches but occasional spirited driving and few laps around a track.

if it's for minimal track days, just spirited driving and better control of the rear end; go with a torsen unit like wavetrac or the new helical one that MFactory is putting out--I'd stay same FD ratio as stock also, keep RPMs down during normal driving/cruising

[bignico_05]

Originally Posted by c_ozanich

if it's for minimal track days, just spirited driving and better control of the rear end; go with a torsen unit like wavetrac or the new helical one that MFactory is putting out--I'd stay same FD ratio as stock also, keep RPMs down during normal driving/cruising

Is the quaife less reliable or just to track oriented and overkill for my use?

[MightyMouseTech]

The Quaife is more street friendly. Clutch type is arguably better for track use, the M3 comes with one.

[c_ozanich]

Originally Posted by bignico_05

Is the quaife less reliable or just to track oriented and overkill for my use?

quaife and wavetrac are often compared together, so yea I would say that's more the lines you want to look at

[MFactory]

If your car is mainly a daily driver/weekend warrior, then I would recommend the Helical LSD over the Plate type LSD.

Helical LSD's (MFactory, Quaife, Wavetrac) are smooth in operation, noise free and require zero maintenance (well, Wavetrac does actually need maintenance if you want to keep it functioning like how they advertise). Helical LSD's also work hand-in-hand with your DTC. Think of DTC as being 50% of the traction solution. With the addition of an LSD, which provides the other 50% solution, you now have a 100% solution to traction issues. However, they are analogue in function and only work upto a pre-determined bias ratio (or % torque transfer). Each LSD has it's own pre-determined bias ratio.

Plate type LSD's (MFactory, OS Giken, Cusco) have increased NVH due to physically locking and plates rubbing together. They also require maintenance as the plates/springs are wear items. Aftermarket Plate type LSD's normally allow pre-load adjustments, engagement angle adjustments, and lock capacity adjustments (ranging from 20-100%). OEM is inferior in this regard.

[gap]

Sounds like the helical differential would be best for you. I got the Mfactory diff and am happy with it. Hardly ever have the traction control light come on now, powers out of a turn without the inside wheel getting the e-diff braking.

[i_love_cars]

Regarding reliability, there aren't enough 1ers with LSDs installed to really have a verifiable sampling. That said, I've yet to hear of anyone blowing out one of those Wavetrack/Quaife diffs on this car even at 500+ wtq.

I've got 10k miles on my Wavetrac and love it. No issues. Spirited driver, 3-4 HPDEs per year.

Most people aren't going to be able to tell a legit difference between MFactory/Quaife/WaveTrac, regardless of what they tell you. Stick with one of those 3 and you'll be happy.

Regarding the comment on maintenance on the WaveTrac, they advertise lifetime function with 0 maintenance (assuming you buy the differential new direct from them).

[bignico_05]

Perfect! Thanks for all the response guys

[MFactory]

Originally Posted by i_love_cars

Regarding the comment on maintenance on the WaveTrac, they advertise lifetime function with 0 maintenance (assuming you buy the differential new direct from them).

The Wavetrac has friction discs inside which wear out. The LSD will still function, but not as they advertise until you have them replace the discs.

[red914]

Slightly off topic but related...

Does installing a LSD in a 135i affect the stability and traction control or will those work the same as without LSD?

[MFactory]

It works hand-in-hand with the DTC i.e A Helical LSD functions where the DTC fails (i.e will bias torque between the left/right wheels, thus providing increased traction), and vice versa, the DTC functions where the LSD fails (i.e will sense a spinning wheel and apply brake, thus allowing the Helical LSD to function again)

[Eyeman]

I've had a Quaife for nearly 60k miles now and my car dynos 400ish HP to the wheels. Prior to the LSD I had sort of gotten my foot accustomed with when the traction control would kick in but I'd still get a light pretty much daily. It was funny, after I had the LSD installed, I kept driving the same way and went like a month without a traction control light. Also I often get significant tire spin but no lights, I guess the LSD keeps them spinning in conjunction.

Make sure you find someone who knows what they are doing on the install, mine was not shimmed properly so it roars.

[BlackBMiLuc]

I'm on the same boat with considering an lsd and which. But the installation cost on top of the price for the lsd has me worried. I'm not sure if it's worth a diy. Anyone with an install from the northeast area?

[135TX]

I get my car back from the shop tomorrow from getting my Mfactory lsd installed. They send you a diff fully built with the lsd loaded and installed you just swap the pumpkin. 3.5 shop hrs.