[tke743]

So here is the plan. I don't have a LSD yet, so right now I'm testing without a mechanical LSD. I get the M performance diff on the 20th, and will be able to compare/contrast at that time. Once the M performance piece is installed, I'm having the original open diff built out with a quaife LSD. After 800 miles or so on the M performance LSD, I'll swap the quaife in and test that.

So for testing, any specific things you want to know?

(Note, my car is still in the break in period, so instead of abusing it to test, I'm taking advantage of the winter conditions here in the northeast. From my experience this is a great testing regimen for drivetrain bits without abusing the car. It is like a hyper exaggerated verson of the testing without mechanical grip being much of the equation.)

Non-LSD testing notes so far.
The car's nannys are quire good in slippery conditions when left on. No surprises in nasty ice, slush, snow. Very quick to react.

Eco-pro - boring, hate it, nuf said.

Comfort - soft, smooth, cruising mode. Nanny heaven.

Sport - it is just comfort mode with firmer suspension along with exaggerated imputs on throttle and stearing, plus the slightest lag in the nannys taking the fun away. You can push harder but the nannys are in control. No discernible e-diff LSD activity.

Sport+ - It is sport, nanny lag is increased to approximately .5 sec of stupidity, then it kicks in hard with the nanny regimen. Fun mode for the street, not track. Great mode for driving below the limits of mechanical grip. E-diff LSD is definitely there, for that approximately .5sec. One wheel spins, that is arrested, both spin, then here come the nannys.

DSC OFF - My favoite mode (not for day to day driving where the nannys have their place, especially on these roads.) No nanny kick in, just the e-diff. Does not have the exaggerated throttle and stearing but keeps the suspension tight. I prefer the lack of the exaggeration, I don't need fake enhancements, and I tell the car when to shift. E-dff is quite good, surprisingly so. Looking forward to seeing how it works with the LSD's. My guess is that they will work in conjunction with each other to give us more then the 30% lock advertised. I've seen telemetry somewhere showing this.

[BMWKLR]

That is exactly the comparison I need to make my decision on which one to install. Thank you in advance.

[bladeomatic]

Can't wait to hear your findings from where I'm sitting in the bleachers.

Thanks!

[spyerx]

How hard is the eDiff on the rear brakes on track? Any experience? Real LSD on track is what you want, you can't power out of corners right w/o one and on heavy braking you'll get the wiggle from an open diff. A real locking diff works on acceleration and deceleration. For street candidly its only good when you want to be a hoon. For track, real diff for sure. Lots of real experience in this when the oem diff in my gt3rs decided it wanted to be an open diff before i put a guard pro lsd in.

[tke743]

Originally Posted by spyerx

How hard is the eDiff on the rear brakes on track? Any experience? Real LSD on track is what you want, you can't power out of corners right w/o one and on heavy braking you'll get the wiggle from an open diff. A real locking diff works on acceleration and deceleration. For street candidly its only good when you want to be a hoon. For track, real diff for sure. Lots of real experience in this when the oem diff in my gt3rs decided it wanted to be an open diff before i put a guard pro lsd in.

Completely agree, but there are a lot of questions on the e-diff so i wanted to give a review of that first. (It will also allow me to compare the car with and without.) I will have a LSD long term, as ithe e-diff (although good on the street) will cook the brakes on the track. Some of my testing above was on sheer ice and the rear brakes were hot after that e-diff session.

[abp689]

Not sure if you would be able to test on a steep slope with snow - seems like that would be a good test for the streets?

Otherwise, look forward to the results!!!

[crqflier]

Subscribing for the BMW and quaife updates.

[foamie]

Originally Posted by tke743

So here is the plan. I don't have a LSD yet, so right now I'm testing without a mechanical LSD. I get the M performance diff on the 20th, and will be able to compare/contrast at that time. Once the M performance piece is installed, I'm having the original open diff built out with a quaife LSD. After 800 miles or so on the M performance LSD, I'll swap the quaife in and test that.

So for testing, any specific things you want to know?

(Note, my car is still in the break in period, so instead of abusing it to test, I'm taking advantage of the winter conditions here in the northeast. From my experience this is a great testing regimen for drivetrain bits without abusing the car. It is like a hyper exaggerated verson of the testing without mechanical grip being much of the equation.)

Non-LSD testing notes so far.
The car's nannys are quire good in slippery conditions when left on. No surprises in nasty ice, slush, snow. Very quick to react.

Eco-pro - boring, hate it, nuf said.

Comfort - soft, smooth, cruising mode. Nanny heaven.

Sport - it is just comfort mode with firmer suspension along with exaggerated imputs on throttle and stearing, plus the slightest lag in the nannys taking the fun away. You can push harder but the nannys are in control. No discernible e-diff LSD activity.

Sport+ - It is sport, nanny lag is increased to approximately .5 sec of stupidity, then it kicks in hard with the nanny regimen. Fun mode for the street, not track. Great mode for driving below the limits of mechanical grip. E-diff LSD is definitely there, for that approximately .5sec. One wheel spins, that is arrested, both spin, then here come the nannys.

DSC OFF - My favoite mode (not for day to day driving where the nannys have their place, especially on these roads.) No nanny kick in, just the e-diff. Does not have the exaggerated throttle and stearing but keeps the suspension tight. I prefer the lack of the exaggeration, I don't need fake enhancements, and I tell the car when to shift. E-dff is quite good, surprisingly so. Looking forward to seeing how it works with the LSD's. My guess is that they will work in conjunction with each other to give us more then the 30% lock advertised. I've seen telemetry somewhere showing this.

Cool project.
It might be worth considering that since the M Performance diff has 30% lock-up on acceleration and 9% on deceleration; unless you know when the e-diff activates, it might be prudent to make sure that the quaife you put in would have pretty similar specs to the M Performance diff so you do not end up activating your e-diff if your quaife activates much later..... anyways, just a suggestion. I would be very interested to see how these 2 compare

[rich8566]

.

[ORIGIN M.]

For the money the Quaife is a no brainer.

Interesting none the less.

[ocN55]

subbed

[tke743]

One addition to the pre-LSD testing.

Hard onto brakes going into a corner with limited grip due to the roads. Major squirm on the off throttle event. So in all modes the e-diff lets it remain open on deceleration. Really hope this improves with the LSD.

[tke743]

Tomorrow is LSD day, and no, not the LSD my HR thought I was talking about...

[Alpine F31]

[sstarrx3]

I can tell no difference between Sport and Sport+

[Liquidpaper]

Originally Posted by spyerx

How hard is the eDiff on the rear brakes on track? Any experience? Real LSD on track is what you want, you can't power out of corners right w/o one and on heavy braking you'll get the wiggle from an open diff. A real locking diff works on acceleration and deceleration. For street candidly its only good when you want to be a hoon. For track, real diff for sure. Lots of real experience in this when the oem diff in my gt3rs decided it wanted to be an open diff before i put a guard pro lsd in.

I actually have some experience with this e-diff on the track -- 7 full days so far.

Frankly, the e-diff is very good. The wear on the rear brakes is minimal. After 5 days, I took the car in for a 5k mile oil change, and my mechanic said the rears were at 80%. You're more likely to smoke the rear pads from actual breaking rather than the e-diff doing its thing.

Also, the "squirming" from hard deceleration isn't from this e-diff, its the tires. When I was running the stock PSS, under hard braking it would squirm. When I switched to a more track oriented tire (Direzza II's), it was straight as an arrow on hard braking on the track.

Just as a point of reference, at Willow Springs (this past weekend), I was dropping from about 130ish (guess) down to maybe 60 (guess) at the end of the front straight going into turn 1. Completely stable.

Seriously, this isn't anywhere close to an old fashioned open diff. Yeah, a true mechanical diff would be better, but the e-diff definitely gets the job done. If you aren't tracking, the LSD is worthless. Even if you are, you don't need it. You'll do fine with the e-diff, just think of an LSD (M Performance, Quaife, or otherwise) as an upgrade.

What year is your GT3RS? Maybe the electronics have improved since then?

[williewonkerz]

Originally Posted by Liquidpaper

Frankly, the e-diff is very good. The wear on the rear brakes is minimal. After 5 days, I took the car in for a 5k mile oil change, and my mechanic said the rears were at 80%. You're more likely to smoke the rear pads from actual breaking rather than the e-diff doing its thing.

I hope you're right, driving in winter in manitoba I feel for that poor traction control light.....

[abp689]

It's the 20th; are you watching the SOU?

[tke743]

Originally Posted by abp689

It's the 20th; are you watching the SOU?

I'm out breaking in the LSD

[FunRevn]

Originally Posted by tke743

I'm out breaking in the LSD

I am curious... When I was breaking in my second Mperformance diff, under moderate to heavy acceleration to the Apex of a corner. The nose of the car would tuck into the corner as if I added steering input. To the point of having to correct mid corner as the power was really coming on.

The second thing that I noticed, is that at under 20 mph when in traffic situation (a lot of on / off throttle) I would hear a clinking sound. This sound could also be initiated when putting the car in R or D.

I am on my second LSD at the moment and hoping that they have found the issue. I hope you will have a better experience than I have had so far.

Thanks.

[tke743]

Originally Posted by FunRevn

I am curious... When I was breaking in my second Mperformance diff, under moderate to heavy acceleration to the Apex of a corner. The nose of the car would tuck into the corner as if I added steering input. To the point of having to correct mid corner as the power was really coming on.

The second thing that I noticed, is that at under 20 mph when in traffic situation (a lot of on / off throttle) I would hear a clinking sound. This sound could also be initiated when putting the car in R or D.

I am on my second LSD at the moment and hoping that they have found the issue. I hope you will have a better experience than I have had so far.

Thanks.

I saw your reports on the clicking and I was watching for it. Mine is silent.

As to the mid corner oversteer, that is what an LSD does. And that is a good thing. On a one wheel drive the inside rear corner is the most unloaded tire of all in a corner, it spins but the outside rear wheel just rolls. The outside wheel has the maximum lateral g capability as there is little to no drive impulse. With an LSD the outside wheel will spin too so it has less lateral grip. There are two options of how to address this.

1) Be more subtle on the throttle until later in the corner, or
2) Give it more throttle and hope the weight transfer is sufficient to increase the grip of the tire and correct the oversteer. Whatever you do, don't lift off.

Note that with #2, too much throttle and you are drifting. So be subtle, an LSD rewards throttle control.

[moldcad]

Originally Posted by tke743

As to the mid corner oversteer, that is what an LSD does. And that is a good thing. On a one wheel drive the inside rear corner is the most unloaded tire of all in a corner, it spins but the outside rear wheel just rolls. The outside wheel has the maximum lateral g capability as there is little to no drive impulse. With an LSD the outside wheel will spin too so it has less lateral grip. There are two options of how to address this.

1) Be more subtle on the throttle until later in the corner, or
2) Give it more throttle and hope the weight transfer is sufficient to increase the grip of the tire an correct the oversteer. Whatever you do, don't lift off.

Note that with #2, too much throttle and you are drifting. So be subtle, an LSD rewards throttle control.

+1