Big LSD Shootout... OS Giken, Drexler, Titan, GKN, ZF...

[driftflo]

yes, i should have a kit laying around in my stock. but why would you want to swap? the e92 m3 pinion ball bearings are quite solid. if set properly they last very long, even when used on track. and you can improve their life even further with the GT4 solid sleeve (instead of crush sleeve).

i got these taper roller bearing conversion kits many years ago when i was not sure if the ball bearings will be capable of motorsports and hard abuse. but i had no issues with all e92 m diffs i built with the ball bearings.

there are other bmw diffs that would need this conversion kit a lot more. even f and g m-diffs do have weaker bearings compared to e92 m!

[tonynguyen]

Originally Posted by driftflo

to keep this thread alive with quality content, here is a comparison of the various hardware setups i offer for e92 m3:

from left to right:
- drexler gt race light
- drexler gt race
- drexler performance
- drexler street




and a closer look to the first "gt race light" (high end, most expensive):



and the low budget alternative. a zf based lsd with modified lockup of 45% . this can be built with an old zf 25% lsd core where i offer perfectly fitting sets of new drexler internals to rebuild to a fresh 45% setup. this will perform very close to the drexler street setup:




and a little warning: i just saw in another thread here that a lsd core was built by some unexperienced guys that did not understand the direction of the power and coast ramps. this poor customer got a setup that is the exact opposite of what he bought/expected (plus the parts itself that were used there will not perform as expected either).

this is basic knowledge and i would call setting up lsd cores as "diy-stuff".
if many shops (i get such ill-working units on a regular basis to get them fixed) even fail to do this correct, the ball bearings setup is a completely different level... and the reason i encourage everybody to have this only done at very experienced shops!

Thank you driftflo for your valuable information. I am looking for LSD upgrade for E90 M3.
I found this: https://osgikenusa.com/collections/l...ducts/bm237-ha it says fit both E46 M3 and E9x M3. Is it a mistake or this same unit can fit to both E46 M3 and E9x M3?
While with this link, seems same unit: https://www.ecstuning.com/b-os-giken...unit/bm237-ha/ it says only fit E46 M3

And how your limitedslip.de LSD compares to OS Giken?

Have a good day

[driftflo]

i tried this os giken unit in 2 different setups ("spec-s" and "spec-x") in my e92 m3 and i was very disappointed on both setups. really not what i expected. plus the quality problems you often hear with os giken units i stopped putting time and effort in making this unit work. plus it is pretty overpriced for a basic "steel on steel" friction material unit. of all units i tested it was the one with the weakest performance (spec-s) and the most NVH (spec-x).
if you are interested in my findings on the osg in detail check the first pages of this thread. i did a detailled writedown with pictures on both setups.

so imho the drexlers are by far better units (really no comparison at all). and even the "low budget" zf based 4cp units are easily outperforming the osg.

fitment of this core mostly depends on ringgear used. if one wants to buy a certain lsd core i ask for the required information and then can choose the right core and according parts to make it fit for that application.

[Bartledoo]

Odd, my spec-x OSG is amazing, and mostly silent on the street. Dry or wet track conditions, I couldn’t ask for better.

[Redd]

I think OSG had some quality issues with a batch of LSDs many years back. That has been resolved but they still carry the stigma of that incident.

[driftflo]

Originally Posted by Redd

I think OSG had some quality issues with a batch of LSDs many years back. That has been resolved but they still carry the stigma of that incident.

really? what was the problem? what went wrong and what did they improve?
why didn't they replace the affected parts on the units sold? or at least why did they not inform their customers about this?
so far, no one informed me... and i guess it is unlikely to happen at all, 9 years later.
mistakes happen... the question is how you deal with it!
so yes, this is a big stigma to me then!

luckily drexler is certified to IATF 16949 and ISO 14001. this is the big advantage of companies that also (or mostly) supply big OEMs. they really (have to) care about quality control.

[driftflo]

due to the many inquiries on drexler lsd cores for bmw m3 e92 and e46:
good news! they are back in stock now. i just got x65 drexler lsd cores for BMW 210 type diffs. each can be built individually to any spec required.

i received ~200 drexler units in total recently, also for bmw 188K/L diffs (non-M E46, E90, Fxx), M2/M4 F82 and also M4 G82.
additionally various Porsche, Merc C63, Toyota GT86, Nissan 370Z, ...

if you require any drexler core that fits your needs and your gearbox, just contact me! worldwide shipping!

[slcook54]

Awesome thread, Florian. Just read the whole thing. I'll be in touch in the near future for my E92 track car.

[Bmwguy88]

What's the best bang for your buck when it comes to LSD's? I'm sure I'm no where near the skill level of seeing a difference when I'm at a track day but I like spending money on car parts.

[driftflo]

Originally Posted by Bmwguy88

What's the best bang for your buck when it comes to LSD's? I'm sure I'm no where near the skill level of seeing a difference when I'm at a track day but I like spending money on car parts.

be sure you will notice the upgrade immediately and quite a lot!
and all lsd cores and setups i offer are a big upgrade compared to the OEM lsd.
in the end it is "you get what you pay for"! the zf45 is a good low budget lsd core, but a drexler "gt race" (best for track, good for street) or "gt performance" (best for street, good for track) are delivering even more traction and rear end predictability while being noticably smoother in reaction and more durable... but you have some bucks more to spend initially.

in between is the drexler "performance"... all the drexler parts, more clutches then zf45 but less then the "gt" setups. so depending on budget get one of these and you will be happy... and feel the difference!!!

[Pete.J]

Originally Posted by driftflo

and all lsd cores and setups i offer are a big upgrade compared to the OEM lsd.

Does this statement also apply to the newer M cars, for example a F82 M4 with active M differential that locks up on demand?

[driftflo]

Originally Posted by Pete.J

Does this statement also apply to the newer M cars, for example a F82 M4 with active M differential that locks up on demand?

absolutely!
the newer e-diff (like used in f and g series m cars) is a little improvement over the old m-variable (used in e46 and e92) but still leaves a lot of room for improvement via fitting a clutch type solution.
even bmw motorsport knows this and installed the clutch type hardware that i offer into their entry level racers m2 racing and m4 gt4 f82&g82 (for high end racecars like the m6 gt3 and m4 gt3 such a clutch type unit is standard as well).
although these two entry-level racecars (m2 racing, m4 gt4) are designed with a low cost approach they opted to change the diff as it will have a big impact and benefit for performance, predictability and also durability.
the e-diff is not very intuitive to drive and tends to fail prematurely when driven hard (i.e. on track).
setup of the e-diff is optimized for unexperienced drivers and safety (of course)... not performance foremost.

so, long story short: expect a big and noticably improvement when upgrading to one of the units/setups i offer based on the oem gt4 hardware and set to the individual requirements of my customers.

i have already ~40 m2/m4 units running (for both, track and street cars), all customers very happy, no complains at all...

[driftflo]

[changster]

This thread needs a bump in 2024.

I just wanted to ask if your LSD setup needs to change if the car increases its power? I have a 2012 BMW 1M and ordering your GT Race through your dealer in the US. I may increase power down the road to 500-550hp. In an ideal world, would I need to send the diff back to you to change the lockup %'s down the road?

Also, how does one determine what shorter FD is best? I know I want shorter gearing vs the stock 3.15 FD, but don't know if I would prefer 3.45 or 3.62 etc without actually driving the car. I understand people do the calculations on paper for rpm/speed in each gear with a new FD, but I can't actually "feel" what that would be like. The car is only used for Togue time attack or the racetrack. It only drives on the street to get to the mountains or the racetrack.

Thanks!

[M3SQRD]

Originally Posted by changster

This thread needs a bump in 2024.

I just wanted to ask if your LSD setup needs to change if the car increases its power? I have a 2012 BMW 1M and ordering your GT Race through your dealer in the US. I may increase power down the road to 500-550hp. In an ideal world, would I need to send the diff back to you to change the lockup %'s down the road?

Also, how does one determine what shorter FD is best? I know I want shorter gearing vs the stock 3.15 FD, but don't know if I would prefer 3.45 or 3.62 etc without actually driving the car. I understand people do the calculations on paper for rpm/speed in each gear with a new FD, but I can't actually "feel" what that would be like. The car is only used for Togue time attack or the racetrack. It only drives on the street to get to the mountains or the racetrack.

Thanks!

Driftflo is the man when it comes to building custom LSDs!

I’m running a 3.62 FD DCT LSD. I started by creating DCT ratios, diff FD and tire diameters to create plots of speed vs. rpm. These plots do show important information such as max top speed vs. stock, speed at readline in each gear and rpm for cruising at 60 & 70 mph (rpm for these speeds are important in determining your tolerance for a “buzzing” engine. The 3.62 FD + raised 8600 rpm redline helps keeps the engine rpm in gears used on track and/or downshifting to keep the revs up. I have a stock ‘12 e92 M3 with 3.15 FD DCT LSD+ 8600 rpm raised redline and in a drag race the 3.62 FD is >= four car lengths at the 1/4 mile. Here’s a video of e46 M3s with stock 3.62, 4.10 (had this on my e46 M3 and similar to 3.62 FD on e9x M DCT), and a 3.91. The video shows you what a shorter FD can do. It’s also awesome putting power down mid corner. You’ll need special DCT software properly setup with the shorter FD (Alex@Alpine, Epic Motorsport, etc.)

[omgzirra_exe]

Originally Posted by changster

This thread needs a bump in 2024.

I just wanted to ask if your LSD setup needs to change if the car increases its power? I have a 2012 BMW 1M and ordering your GT Race through your dealer in the US. I may increase power down the road to 500-550hp. In an ideal world, would I need to send the diff back to you to change the lockup %'s down the road?

Also, how does one determine what shorter FD is best? I know I want shorter gearing vs the stock 3.15 FD, but don't know if I would prefer 3.45 or 3.62 etc without actually driving the car. I understand people do the calculations on paper for rpm/speed in each gear with a new FD, but I can't actually "feel" what that would be like. The car is only used for Togue time attack or the racetrack. It only drives on the street to get to the mountains or the racetrack.

Thanks!

if you're in Taipei you will benefit a lot with the 3.62 with the tighter "mountain" roads and the tracks there would benefit from it as well, especially if you do track days at PenBay Int.

from experience

[changster]

Thanks M3SQRD omgzirra_exe

Don't forget I have a 1M not an E92 M3. I'm just posting in this thread since it's THE LSD thread.

Would you still choose a 3.62 over a 3.45 if the redline rpm is at 7000rpm?

[M3SQRD]

Originally Posted by changster

Thanks M3SQRD omgzirra_exe

Don't forget I have a 1M not an E92 M3. I'm just posting in this thread since it's THE LSD thread.

Would you still choose a 3.62 over a 3.45 if the redline rpm is at 7000rpm?

You’d have to model the speed vs rpm for each transmission gear ratio and rear tire size to see the impact of different diff FDs (there are websites that allow you to generate the curves and only needs trans gear ratios, diff FD and tire dia). What’s the stock 1M diff FD? What’s the typical top speed you hit? Shorter FD will lower your top speed. You’ll also want to see at what rpms are you running for 60-80 mph (long road trips).

[changster]

Originally Posted by M3SQRD

You’d have to model the speed vs rpm for each transmission gear ratio and rear tire size to see the impact of different diff FDs (there are websites that allow you to generate the curves and only needs trans gear ratios, diff FD and tire dia). What’s the stock 1M diff FD? What’s the typical top speed you hit? Shorter FD will lower your top speed. You’ll also want to see at what rpms are you running for 60-80 mph (long road trips).

I've already done all that but still don't have a "feel" for what it will be like! Any help is appreciated. Stock FD is 3.15. My tuner says he's comfortable raising the redline to 7400 from 7000.

See attached pics.

I use the car only for the track or canyon carving. When I say canyon carving I am flat out on it like time attack. If you ever watch the Best Motoring videos in the Japanese mountains, it's like that. No commuting except to/from the track or mountains.

Car is a manual 6MT not DCT.

[M3SQRD]

Originally Posted by changster

I've already done all that but still don't have a "feel" for what it will be like! Any help is appreciated. Stock FD is 3.15. My tuner says he's comfortable raising the redline to 7400 from 7000.

See attached pics.

I use the car only for the track or canyon carving. When I say canyon carving I am flat out on it like time attack. If you ever watch the Best Motoring videos in the Japanese mountains, it's like that. No commuting except to/from the track or mountains.

Car is a manual 6MT not DCT.

I find it much easier to view the data on a plot of speed vs. rpm for each gear. I also stop the speed when redline is reached and if gear 1 gets you 40 mph, I find the corresponding rpm for 40 mph on gear 2, then gear 2 redline speed of 65 mph found on gear 3, etc. so you see the speed at the beginning of the gear and the max speed at redline for same gear. The steeper the gear mph vs. gear rpm curve, the higher the acceleration. Now you can compare slopes, starting mph and peak mph for each gear which can easily be compared to different FD ratios.

With the e36 M3 trans ratios and 3.15 FD, the 3.62 FD is a solid useable street-track diff FD which allows you to still hit 170 mph in 6th gear and cruising rpm at 80 mph is ~3250 rpm. If you used a model that estimates the deformation of the rear tire under load, the deformed tire results in 2-4% additional shorter gearing.

The 3.45 FD would be the better 100% street option but the 3.62 FD has the best track performance yet is still street friendly. You’ll definitely feel the difference between either one. I went with 3.62 on my e92 M3 because it pulls harder and had roughly the same shortened gear ratio as my e46 M3 with a 4.10 FD.

[omgzirra_exe]

Originally Posted by changster

Thanks M3SQRD omgzirra_exe

Don't forget I have a 1M not an E92 M3. I'm just posting in this thread since it's THE LSD thread.

Would you still choose a 3.62 over a 3.46 if the redline rpm is at 7000rpm?

sorry! i forgot it was a 1M.

i would do 3.46 and play with tire sizing, starting at 275/35/18 assuming you are running 18x10 ET25. this would be MY ideal set up.

this is what you'd end up with..

1: 37.46 MPH 60.28 KPH
2: 66.50 MPH 107.02 KPH
3: 99.84 MPH 160.68 KPH
4: 130.58 MPH 210.15 KPH
5: 153.95 MPH 247.76 KPH
6: 181.98 MPH 292.86 KPH

this would be GREAT for your roads and track. you would be well within your powerband at every gear pretty much.

I would avoid raising the RPM to 7400 for the sake of saving your engine, that could introduce valve float and causing you to dislodge one. so you'd need to build your head for me personally to be okay with that extra 400RPM.

doing the 3.46FD would be the better play especially on a car that can easily make 500WHP...so 3.62 is out of the question for me!

[driftflo]

Originally Posted by changster

I just wanted to ask if your LSD setup needs to change if the car increases its power? I have a 2012 BMW 1M and ordering your GT Race through your dealer in the US. I may increase power down the road to 500-550hp. In an ideal world, would I need to send the diff back to you to change the lockup %'s down the road?

in case of more power you do not need to change your lsd setup. it depends more on the application you use the car for and the amount of grip you have/expect.
if you want to have the setup changed the lsd needs to be pulled out and being disassembled and the assembled back with the new setup/parts.

Originally Posted by changster

Also, how does one determine what shorter FD is best? I know I want shorter gearing vs the stock 3.15 FD, but don't know if I would prefer 3.45 or 3.62 etc without actually driving the car. I understand people do the calculations on paper for rpm/speed in each gear with a new FD, but I can't actually "feel" what that would be like. The car is only used for Togue time attack or the racetrack. It only drives on the street to get to the mountains or the racetrack.

for the 1M i definitely would suggest the 3.45 over an even shorter one. the 1M is a FI engined car with different engine characteristics (more torque at less rpm) compared to the low torque, high revving s65. so for a E92 dct i'd suggest to go from stock 3.15 to 3.62. for the 1M i'd switch the 3.15 to a 3.45! i did several 1M diffs with that ratio and feedback was always it was "just right".