Random pics of my recent mod -- limited slip differential (LSD)

[Bruck]

Care to comment on what this mod did to your DSC unit - is it completely disabled?

[coolguy]

Originally Posted by Fedorov

What is "LSD" and what does it do?

Limited slip differential
Link: http://en.wikipedia.org/wiki/Limited_slip_differential

[coolguy]

Originally Posted by Bruck

Care to comment on what this mod did to your DSC unit - is it completely disabled?

Nope. LSD acts a lot quicker before the dsc kicks in

[Bruck]

Originally Posted by Fedorov

What is "LSD" and what does it do?

LSD stands for Limited Slip Differential. An LSD is a replacement mod for non M cars (which like many other automobile come with standard differential).

The Differential is the last piece of machinery which hands the power from the engine to the wheels. In our car's case, this is the rear wheels. Upgrading to a Limited Slip Differential changes the way in which the car is allowed (or capable) to transfer power between both wheels when they are not rotating at the same speed.

When one wheel is slipping in a standard diff car, power is removed from the wheel with traction and handed to the one without. In most scenarios DSC will also apply brakes at the same time to the wheel with traction to slow it down in an attempt to correct the slippage (otherwise known as 1 wheel moving faster than the other)

On a car with an LSD, power can be given to both wheels unevenly, this allows for much more effective drifting and car control, as well as maintained forward motion during instances of slippage. When you are on a track, wheels slip all the time... this is why an M car can often out shine a non-m because when it starts to slide, it can keep moving forward... thus being faster around the track (in some cases)

If this wasn't entirely accurate, someone can correct.

[TheDarkone]

holy pictures batman! Would have been nice if there were descriptions under each picture so we would know what we're looking at.

nice mod tho. so jealous. you are the only 1

[Fedorov]

Originally Posted by Bruck

LSD stands for Limited Slip Differential. An LSD is a replacement mod for non M cars (which like many other automobile come with standard differential).

The Differential is the last piece of machinery which hands the power from the engine to the wheels. In our car's case, this is the rear wheels. Upgrading to a Limited Slip Differential changes the way in which the car is allowed (or capable) to transfer power between both wheels when they are not rotating at the same speed.

When one wheel is slipping in a standard diff car, power is removed from the wheel with traction and handed to the one without. In most scenarios DSC will also apply brakes at the same time to the wheel with traction to slow it down in an attempt to correct the slippage (otherwise known as 1 wheel moving faster than the other)

On a car with an LSD, power can be given to both wheels unevenly, this allows for much more effective drifting and car control, as well as maintained forward motion during instances of slippage. When you are on a track, wheels slip all the time... this is why an M car can often out shine a non-m because when it starts to slide, it can keep moving forward... thus being faster around the track (in some cases)

If this wasn't entirely accurate, someone can correct.

Very good answer, thank you!

I bet one could wonder why this isn't standard on all cars but I guess that in everyday life when your car start to slip it is time to slow down and drive more careful? This LSD is then more useful when racing than for safe driving?

[jtsherri]

Originally Posted by Fedorov

I guess that in everyday life when your car start to slip it is time to slow down and drive more careful?

I guess I've been doing it wrong all along... Generally this is when I "stand on it."

[coolguy]

Originally Posted by Fedorov

Very good answer, thank you!

I bet one could wonder why this isn't standard on all cars but I guess that in everyday life when your car start to slip it is time to slow down and drive more careful? This LSD is then more useful when racing than for safe driving?

U can use it both ways. It helps in snow and slippery surfaces when it locks both the wheels so you can have more traction or u can rip it if u want to and do some power slides

[bluemoon]

What's the gear ratio on the LSD?

[coolguy]

Originally Posted by bluemoon

What's the gear ratio on the LSD?

3.46 which gives you more accl. It is the only one for step. For manual i think there is one more option of 3.08?

[Bruck]

Originally Posted by coolguy

Nope. LSD acts a lot quicker before the dsc kicks in

Im impressed that swapping out the Differential was such a modular application. Doesn't the car notice that eLSD is gone? Or is it still present and still applicable? (I wouldn't expect it to be).

I'm just curious how a DSC system which expects a standard diff is able to simply work with no tweaks using an LSD.


Its awesome tho that it works!

[coolguy]

The elsd is still there. But quaife lsd acts so fast and takes over before elsd kicks in. The elsd is just like an extra precaution for us incase the regular lsd fails which is very rare.

Originally Posted by Bruck

Im impressed that swapping out the Differential was such a modular application. Doesn't the car notice that eLSD is gone? Or is it still present and still applicable? (I wouldn't expect it to be).

I'm just curious how a DSC system which expects a standard diff is able to simply work with no tweaks using an LSD.


Its awesome tho that it works!

[jtsherri]

Originally Posted by Stankia

Is it 100% blocked?

I *believe* the e-diff should ONLY interact if one of the wheels lifts off the ground, otherwise the LSD should always react faster than the e-diff would...

[Moderato]

Originally Posted by Bruck

Im impressed that swapping out the Differential was such a modular application. Doesn't the car notice that eLSD is gone? Or is it still present and still applicable? (I wouldn't expect it to be).

I'm just curious how a DSC system which expects a standard diff is able to simply work with no tweaks using an LSD.


Its awesome tho that it works!

Good point, the DSC software can't possibly be as effective if it's programed for an open diff and you install a limited slip diff, however once you have the LSD then you can completely disable DSC and reap the rewards.

[Kevin The Clean 1]

Originally Posted by jtsherri

I *believe* the e-diff should ONLY interact if one of the wheels lifts off the ground, otherwise the LSD should always react faster than the e-diff would...

Very interesting mod. Makes me think how much better the two systems will work when you have them both...

[Dr.Sommer]

Hello Coolguy!

Very nice addition of the LSD!
How about the radial seals near the diff carrier bearings - could they be reused after prying them out of their seats?
Was it necessary to put different shims or circlips to achieve proper bearing distance?

[Bruck]

Originally Posted by Moderato

Good point, the DSC software can't possibly be as effective if it's programed for an open diff and you install a limited slip diff, however once you have the LSD then you can completely disable DSC and reap the rewards.

For a track car, or someone who doesn't use DSC, this i awesome...... but for a daily driver, I wonder if there are safety concerns.

The OP isn't the first to mod a non M car with an LSD how have other BMW's behaved in the past?

[jtsherri]

Originally Posted by Bruck

For a track car, or someone who doesn't use DSC, this i awesome...... but for a daily driver, I wonder if there are safety concerns.

The OP isn't the first to mod a non M car with an LSD how have other BMW's behaved in the past?

It's really all a matter of who's driving... I think the e-diff does an excellent job; however, my definition of a *proper* handling RWD vehicle is one that would behave if it had an LSD.

I mean this with no disrespect to anyone reading, but safety is really only a concern for those that don't know how to react in different "interesting" situations when behind the wheel of a vehicle. These are the same people that should invest in driving school prior to an LSD...

Just my $.02

[Moderato]

Originally Posted by Bruck

For a track car, or someone who doesn't use DSC, this i awesome...... but for a daily driver, I wonder if there are safety concerns.

The OP isn't the first to mod a non M car with an LSD how have other BMW's behaved in the past?

Your concern is valid. Not to mention there are different types of LSDs that vary in the way they work as well. That's the nice thing about getting an ///M car, the software is optimised for the LSD and it's a complete package. For a modified car, the action of the LSD & the car, needs to be predictable, once you get used to what it's going to do and trust that, then you can drive with DSC off and feel certain. If the LSD action or setup of the car/suspension, etc...is unpredictable then you're going to be nervous about turning off DSC. For me that's the excitement of a well setup RWD car, like taming a wild horse or something.

[Gogud]

I am disappionted by this thread. These concerns have already been discussed. A few people who have installed an lsd have described their experiences. All the hand wringing and worrying seem unnecessary. If you still have questions, why not direct those to them?

[coolguy]

Originally Posted by Dr.Sommer

Hello Coolguy!

Very nice addition of the LSD!
How about the radial seals near the diff carrier bearings - could they be reused after prying them out of their seats?
Was it necessary to put different shims or circlips to achieve proper bearing distance?

U need new seals which cost 34$. Also u need a new big bolt which can be seen towards the end of the housing in the pictures. It's the same shim which was used as far as I can remember.

[coolguy]

Originally Posted by Bruck

For a track car, or someone who doesn't use DSC, this i awesome...... but for a daily driver, I wonder if there are safety concerns.

The OP isn't the first to mod a non M car with an LSD how have other BMW's behaved in the past?

Trust me. The car is as safe/more safe than before plus lot more fun ( doing some slides in the snow today )