LSD and Ediff

[ehnaych]

Originally Posted by WAY

What is the theoretical limit of the 3.08?

Top speed in top gear would theoretically be 186.15 mph or 299.58 kph.


~Noel

[WAY]

Advevo, does your LSD makes noise at low speed turns like when going around the carpark? Would a Quaife do that? I have never ventured into aftermarket LSD so would appreciate your guidance. Also if anyone else knows this I would love to hear about it. Surely someone here knows someone with a 335i who has installed Quaife?

[Rephlex]

I have the Quaife fitted to my 130i and it does not make a noise.

Here is the demo 335i of www.birdsauto.com who did the work to my car, showing the Quaife doing it's thing. VIDEO

The car is also remapped to 370bhp so it shows the potential of the 135i

[mkiiieustyle]

looks good i am glad to hear that the mechanical diff and e-diff co-exist with each other rather than them acting against each other, An LSD is high on the "to do list" of my 1'er......

thnx for the info.

[Mahlzeit]

Here's a sampling of what a 335 + LSD + PROcede can do.

-Mahlzeit

[WAY]

Originally Posted by Rephlex

I have the Quaife fitted to my 130i and it does not make a noise.

Here is the demo 335i of www.birdsauto.com who did the work to my car, showing the Quaife doing it's thing. VIDEO

The car is also remapped to 370bhp so it shows the potential of the 135i

I am very interested to hear about your experience with Quaife. Does it drive exactly like it was previously? Have you noticed any issues?

[white911]

We continue to go around on this -- it seems that you need to consider what your intended use is. I would not put a Quaiffe in my car, because a Quaife (or TBD) functions as an open dif when a wheel is off the ground. I have a Guard unit in my 911. The Guard site provides a lot of useful information even though their products are for 911s, they sell both types of diferentials. Their site and the associated link to Velocity addresses applications.

http://www.guardtransmission.com/lsd_info.htm

[Powerman]

^^^ Thanks, good reading.


What I want to know is about the E-Diff and a torque biasing diff. While they have their disadvantages when lifted, or on ice, that can be overcome by brake use. I really want to know if the E-diff will actuate and break the spinning wheel and transfer torque to the other side, and by way of a torsen, multiply that torque. I understand that it ultimatly will not function the same as a friction based LSD, it would still be interesting and an improvement to torque biasing units.

[larryn]

Originally Posted by Rephlex

I have the Quaife fitted to my 130i and it does not make a noise.

Here is the demo 335i of www.birdsauto.com who did the work to my car, showing the Quaife doing it's thing. VIDEO

The car is also remapped to 370bhp so it shows the potential of the 135i

Originally Posted by Mahlzeit

Here's a sampling of what a 335 + LSD + PROcede can do.

-Mahlzeit

In the 335i cars that I've driven with the stock open diff, along with my e90 330i, I would smoke the inside tire badly even thinking about doing what these videos show, when turning off the DTC/DSC. With it on, you get no wheel spin.

However, on the videos of the 135i in the wet (via Advevo's youtube videos), and in the dry (via 5th Gear's test), I can see the 135i pretty much duplicating what both of the above 2 videos show.

First, I'll 100% agree that the eLSD will not be a true replacement for a true limited slip. It appears to be a semi-decent alternative to it though. I'll never be entering drift competitions, and I know that that being ass-happy on the track is a pretty damn slow way to get around it. I do want to power out of the corners as soon as possible though, and it certainly appears I might be able to accomplish that fairly well with the eLSD.

The big test is autocross, where you are constantly in situations where you would be upsetting the balance of the car and getting on the gas. I'll be attending my first in the 135i on 4/27, followed by an EVO school a week later.

[WAY]

Larryn, will the eDiff not reduce the torque you have available coming out of corners because it is braking the wheel that torque is going to? Unless e-diff is actually smart enough to transfer the torque to the other wheel? I don't believe the diff is set up to do this as it is still an open diff. Is my understanding correct?

White 911, I am not that concerned about when the wheel is in the air. That is taking it to the extreme and I am not racing the car.

[Powerman]

Originally Posted by WAY

Larryn, will the eDiff not reduce the torque you have available coming out of corners because it is braking the wheel that torque is going to? Unless e-diff is actually smart enough to transfer the torque to the other wheel? I don't believe the diff is set up to do this as it is still an open diff. Is my understanding correct?

White 911, I am not that concerned about when the wheel is in the air. That is taking it to the extreme and I am not racing the car.

Torque will be transfered by way of the open diff. Power seeks the path of least resistence. All power will go to the wheel with no traction. The e-diff will "transfer" torque to the other wheel with traction directly proportional to the braking force applied.

[larryn]

Thanks Powerman. That is correct. Also, brakes will only be applied momentarily, until the inside wheel regains traction. Since all this is happening in fractions of a second, the brakes should not be applied that frequently.

I'm expecting that since front pads normally wear out before rears, this may equal things out, at the worst. Either way, it could make things heat up more in the rear, so make sure you use a decent synthetic brake fluid, if you plan to track the car. BMW also covers brake pads and rotors as part of their covered maintenance too.

[WAY]

Thanks Powerman. That is really reassuring to hear. Larryn, only those of you in North America get the brake pads and rotors covered. Those of us from other parts of the world won't.

[Powerman]

Originally Posted by WAY

Thanks Powerman. That is really reassuring to hear. Larryn, only those of you in North America get the brake pads and rotors covered. Those of us from other parts of the world won't.

No problem. Bottom line is it sounds better than a plain open diff, and it is very easy to accomplish with 4 wheel ABS. Can't be that much cost associated with it. Sort of sounds like a no brainer.

As far as one wheel off the ground, I doubt I will get there either. However, what torque biasing diffs do is "multiply" torque to the other side. If there is no torque, wheel in the air or tire on ice, then zero times anything will be zero. Folks that use these for off-road, like me, use brake to send torque to the other side. That is why it's interesting to think of this e-diff with a torque biasing diff.

[larryn]

Sorry WAY. I constantly forget I'm replying to people from all over. (insert 'other' joke here) :wink:

[WAY]

Why am I not surprised Larryn? Afterall, I live in "Other" so I am not significant!

[Powerman]

White911, or anyone else, why does LSDs help with braking? I understand the LSD is locked up to bias, and the torque biasing unit only works with torque applied, but how does that help on deceleration? There is no differentiation, and there is no throttle applied. If you are trail braking and turning it is differentiating any way. Understand I know nothing about racing. So why is a LSD better than a Quaife for braking?

[Yearofthe1]

Originally Posted by Powerman

No problem. Bottom line is it sounds better than a plain open diff, and it is very easy to accomplish with 4 wheel ABS. Can't be that much cost associated with it. Sort of sounds like a no brainer.

As far as one wheel off the ground, I doubt I will get there either. However, what torque biasing diffs do is "multiply" torque to the other side. If there is no torque, wheel in the air or tire on ice, then zero times anything will be zero. Folks that use these for off-road, like me, use brake to send torque to the other side. That is why it's interesting to think of this e-diff with a torque biasing diff.

Wow, that is an interesting thought. That's my only hang-up between a friction-based LSD and the Quaife style, is the eventual need to replace the friction plates as opposed to a gear-based LSD (the Quaife) which would not need that type of maintenance. If the 1er's eDiff is actually able to complement the mechanism of a Quaife-style LSD, than that may definitely sell me on the Quaife. We do need to hear some real-life testimony comparing the bahaviour of these two set-ups!

[Powerman]

Originally Posted by Yearofthe1

Wow, that is an interesting thought. That's my only hang-up between a friction-based LSD and the Quaife style, is the eventual need to replace the friction plates as opposed to a gear-based LSD (the Quaife) which would not need that type of maintenance. If the 1er's eDiff is actually able to complement the mechanism of a Quaife-style LSD, than that may definitely sell me on the Quaife. We do need to hear some real-life testimony comparing the bahaviour of these two set-ups!

Same here. I like my gear LSD in my Jeep, but I know it's limits. In that application though, a LSD would not be much different, I will be putting a selectable locker in like my rear in the future.

Even if the Ediff and gear LSD can match a LSD say 80%, then hat would probably be good for me. I want to track my car for the fun of it, but my driving skills will limit me much longer than a Quaife will:biggrin:

[colonel1961]

WTF is LSD (other than college chemistry...)?

[atr_hugo]

Limited Slip Differential

[colonel1961]

A somewhat lame attempt at humor - mea culpa.