What about Limited Slip Differentials?

[WolfGTI]

Has anyone heard of an LSD option for the 1 series yet? With the tuning potential of this car, an LSD is a must have for serious drivers.

[321]

nope.. not from the factory... yet.

[mikeo]

Several threads already in existence on this subject--please search.

[Spoonie]

LSD's are overrated for street use IMO. How often are you going to go balls out around turns (on public roads) in a 300hp vehicle? Even on the race track a 335 w/o LSD beat out a more powerful Z4 W/LSD.

LSDs are good for shaving 10ths off of a lap time (and not even that all the time as mentioned above) or hard driving in bad weather.


Having an LSD didn't help the infiniti G37. It still lost out in handling to the 335 (a car w/o LSD).

I'll gladly take an LSD, I just don't think that it is really needed.

[Rook24V]

I love limited slip diffs in my cars, especially good on wet days as you kick the tail out slightly and hold it with a little more throttle and countersteering. I'd HAVE to get an LSD, its almost worthless driving a RWD car without one.

[Spoonie]

Originally Posted by Rook

I love limited slip diffs in my cars, especially good on wet days as you kick the tail out slightly and hold it with a little more throttle and countersteering.

I can do that with my NON-LSD 330i. In fact I love the rain just because of it.

[Chibana]

Originally Posted by Rook

I love limited slip diffs in my cars, especially good on wet days as you kick the tail out slightly and hold it with a little more throttle and countersteering. I'd HAVE to get an LSD, its almost worthless driving a RWD car without one.

I can second the love for a good LSD/ATBD. I installed a Quaife ATB differential in my Mazda3, originally with the intent of installing a HiBoost turbo in it. I've since decided not to bother with the turbo, but the difference with the Quaife is obvious even at nearly stock power levels. I can now get on the gas, and stay on the gas, going around turns with no problems, and it's quite fun to have both tires spinning simultaneously when I punch it, straight or turning. The difference in traction last winter here in Michigan was significant, and I no longer have to worry about driving over patches of slippery road on just one side of the car. The Quaife is the best mod I've ever done on any of my cars. My previous car was a 2001 ZX3 with 13 psi Jackson Racing supercharger with water/methanol injection for cooling (200 whp, 194 lb-ft torque), and I never did the Quaife. I decided I would not make that mistake again.

[imported_MPower]

I guess there is a quota of one LSD-related thread per day...

Tip of the Day: searching is your friend (or simply scrolling down the thread list...)

[grant]

Originally Posted by Spoonie

I can do that with my NON-LSD 330i. In fact I love the rain just because of it.

Works MUCH better with LSD (more controllable) and also works much better if you don't want the tires to just spin and actually move the car forward quickly...

[ducati]

Originally Posted by Spoonie

LSD's are overrated for street use IMO. How often are you going to go balls out around turns (on public roads) in a 300hp vehicle? Even on the race track a 335 w/o LSD beat out a more powerful Z4 W/LSD.

LSDs are good for shaving 10ths off of a lap time (and not even that all the time as mentioned above) or hard driving in bad weather.


Having an LSD didn't help the infiniti G37. It still lost out in handling to the 335 (a car w/o LSD).

I'll gladly take an LSD, I just don't think that it is really needed.

LSD's don't make the car. But a good car is always BETTER with a LSD.

And with 300 lb-ft of torque at 1400 rpms, all you're going to get around tight corners is useless acceleration-robbing wheelspin, or heavy "e-diff" action slowing you down.

Add to that a LSD-equipped car is more predictable to drive when you do spin the rears up (and you will in the 135).

LSD's FTW, even on the street.

[fritZman]

Originally Posted by Spoonie

LSD's are overrated for street use IMO. How often are you going to go balls out around turns (on public roads) in a 300hp vehicle? Even on the race track a 335 w/o LSD beat out a more powerful Z4 W/LSD.

LSDs are good for shaving 10ths off of a lap time (and not even that all the time as mentioned above) or hard driving in bad weather.


Having an LSD didn't help the infiniti G37. It still lost out in handling to the 335 (a car w/o LSD).

I'll gladly take an LSD, I just don't think that it is really needed.

A good LSD is worth far more than just 10ths off a lap time. When I swapped my weak OEM 350Z viscous LSD for a stronger Cusco clutch 60% lsd, my Solo2 times dropped almost 1 second per minute - exactly what a professional race team had previously PM'd me would happen based on their personal experiences.

On the street a good LSD isn't always needed to hammer the throttle out of a tight turn (although it can help when merging onto a busy street), it's the traction & predictability you get when conditions are wet and even snowy.

Personally I think the 135i should definitely come with a LSD of some sort - even if it were a $1K option.

[atr_hugo]

Originally Posted by fritZman

A good LSD is worth far more than just 10ths off a lap time. When I swapped my weak OEM 350Z viscous LSD for a stronger Cusco clutch 60% lsd, my Solo2 times dropped almost 1 second per minute - exactly what a professional race team had previously PM'd me would happen based on their personal experiences.

On the street a good LSD isn't always needed to hammer the throttle out of a tight turn (although it can help when merging onto a busy street), it's the traction & predictability you get when conditions are wet and even snowy.

Personally I think the 135i should definitely come with a LSD of some sort - even if it were a $1K option.

+1 - I've had a couple of cars with OEM LSDs and neither of them could match the precision of the Mustang Cobra R diff in being able to place the rear of the car - to the milimeter - where I wanted it. It is a whole different feeling coming into a hairpin turn - getting the backend out and being able to hold it exactly where you want it with the throttle because you have a COMPETENT LSD.

[1ster]

Originally Posted by fritZman

Personally I think the 135i should definitely come with a LSD of some sort - even if it were a $1K option.

I think we all agree with you. Hell, you can order a Mini Cooper S with a limited slip! Nonetheless, this one falls under the category of Ain't Gonna Happen because it will muck with BMW's plan that only M cars get mechanical diffs.

Not offering an LSD also keeps the 135i in its place in the heirarchy. We wouldn't want a bold upstart to get too uppity, now would we?

My only question is whether a mechanical diff is a realistic upgrade or whether the E-diff software will get confused/blow up if you install one.

[adc]

Originally Posted by Spoonie

LSD's are overrated for street use IMO.

Well so are the average driver's driving skills. So what?

We don't buy average, we buy top tier, right?

How often are you going to go balls out around turns (on public roads) in a 300hp vehicle?

Each day at least once. It's how I manage to leave family problems at home and work problems at the office.

Even on the race track a 335 w/o LSD beat out a more powerful Z4 W/LSD.

On one track - VIR. But not on another - Nurburgring. Maybe the driver was crap.

LSDs are good for shaving 10ths off of a lap time (and not even that all the time as mentioned above) or hard driving in bad weather.

Absolutely correct, they do all that.

As far as I am concerned, they are also good for predictability - with an open diff, in many cases the car will do either understeer/one wheel spin, or oversteer/two wheel spin. I can take the same corner over and over again and obtain different results in each pass - in fact I do that every day. It's really a crap shoot.

In my buddy's E36 M3, it's nice oversteer all the way, every time the same thing. Does wonders for someone's confidence and consistence.

Having an LSD didn't help the infiniti G37. It still lost out in handling to the 335 (a car w/o LSD).

If the 335 had a limited slip, the G would have been creamed. Check out the Hartge-modified 335i review from Top Gear on youtube. It's the difference between good and great. Blended vs. single malt.

Almost every reviewer of the 335i has mentioned their wish for a LSD.

I'll gladly take an LSD, I just don't think that it is really needed.

Neither is Angelina Jolie. But I still want one...


Look, you've posted on this topic numerous times. People have already been through this with you - you don't like limited slips, you don't want them. Fine. We get it.

Why exactly do you oppose this as becoming an OPTION, is simply beyond me. Nobody would shove one down your throat...

[fritZman]

Originally Posted by 1ster

... My only question is whether a mechanical diff is a realistic upgrade or whether the E-diff software will get confused/blow up if you install one.

Agreed the 135i will very likely not see a diff option.

As long as there is a e-diff/traction/skid disable button, I see no reason why a mechanical diff wouldn't be beneficial.

In fact, because most traction/skid software is reactive in nature (especially in lower end models), having an aftermarket diff to enhance the mechanical effectiveness will only delay, and not hurt, the potential onset of electronic interference. That's the biggest difference I noticed on my 350Z running an aftermarket diff with the traction/skid control on.

A problem could arise if the e-diff/traction/skid software runs a proactive/prediction model based on inputs from throttle/steering and possibly lateral acceleration meters. In that case it's possible the e-diff would cause premature braking to one of the drive wheels even though mechanical grip is still available thanks to the superior performance of an aftermarket diff. In that scenario, the e-diff would negate the aftermarket's LSD benefit altogether.

So I guess the answer is to find out how sophisitcated the 1-series software is, and if a disable button is provided. Either way, I doubt it would actually hurt the vehilce.

[Spoonie]

Originally Posted by adc

Well so are the average driver's driving skills. So what?

We don't buy average, we buy top tier, right?



Each day at least once. It's how I manage to leave family problems at home and work problems at the office.



On one track - VIR. But not on another - Nurburgring. Maybe the driver was crap.



Absolutely correct, they do all that.

As far as I am concerned, they are also good for predictability - with an open diff, in many cases the car will do either understeer/one wheel spin, or oversteer/two wheel spin. I can take the same corner over and over again and obtain different results in each pass - in fact I do that every day. It's really a crap shoot.

In my buddy's E36 M3, it's nice oversteer all the way, every time the same thing. Does wonders for someone's confidence and consistence.




If the 335 had a limited slip, the G would have been creamed. Check out the Hartge-modified 335i review from Top Gear on youtube. It's the difference between good and great. Blended vs. single malt.

Almost every reviewer of the 335i has mentioned their wish for a LSD.



Neither is Angelina Jolie. But I still want one...


Look, you've posted on this topic numerous times. People have already been through this with you - you don't like limited slips, you don't want them. Fine. We get it.

Why exactly do you oppose this as becoming an OPTION, is simply beyond me. Nobody would shove one down your throat...

You just convinced me on the Merits of LSD. The comment about the crap shoot really hit home. There's a nice semi-tight turn on my way to the job. In the rain I'll get her all crossed up. The only problem is that sometimes I'll nail it, and other times it doesn't come out so good. I just thought It was my driving skills.

[R32]

the real shame is that an lsd could be a $500 factory option, but it would probably cost $2K (or more) to purchase and install in the aftermarket.

as for the skeptics, i'm sure that the e-lsd car would be very close to a car with a real lsd around a track in terms of lap times. but what happens to the rear brakes after they have been applied an extra 10-20 times per lap, for an entire 30 minute session, or the end of a day with 4 or more such sessions?

[mikeo]

Originally Posted by R32

the real shame is that an lsd could be a $500 factory option, but it would probably cost $2K (or more) to purchase and install in the aftermarket.

as for the skeptics, i'm sure that the e-lsd car would be very close to a car with a real lsd around a track in terms of lap times. but what happens to the rear brakes after they have been applied an extra 10-20 times per lap, for an entire 30 minute session, or the end of a day with 4 or more such sessions?

Good questions, but the answers are months away. I'm curious how it will perform at autocrosses, where brake heating should not be a problem.

[ducati]

Originally Posted by R32

the real shame is that an lsd could be a $500 factory option, but it would probably cost $2K (or more) to purchase and install in the aftermarket.

as for the skeptics, i'm sure that the e-lsd car would be very close to a car with a real lsd around a track in terms of lap times. but what happens to the rear brakes after they have been applied an extra 10-20 times per lap, for an entire 30 minute session, or the end of a day with 4 or more such sessions?

Why are you sure of this?

VW's newest EDL technology aggressively cuts engine power while applying the brakes. This severely retards acceleration, although it does have the effect of transferring power.

Why does VW do this? My hunch is that its related to the rash of transmission failures in the old MKIII GTI VR6s when aggressively driven. Those cars had braked-e-diffs only (no spark cut), and they basically hammered themselves apart. VW would replace the tranny once under warranty (for most folks), and then you were on your own. I never tracked my GTI, although I did autox it a few times, as well as (normal!) spirited street driving, and my tranny was failing at 8k miles.

Land Rover faced a similar issue with the Discovery II 4ETC. If used offroad quite a bit, a Disco II will eventually hammer its diffs into bits. Even on street-driven Discos, the diff wear is incredible. Try draining a Disco II diff and see what I mean. Metal bits.

Land Rover got away from this technology with the Discovery 3 (LR3); they have programmed the system to apply the brakes more softly, which should prolong diffs; but they have also added a center locking diff as standard and a rear locker as optional. Why? Because locked up is much easier on the drivetrain than brakes hammering away. And much more effective off-road, I might add.

I am not aware of any electronic "brake-action limited slip" diff that outperforms its mechanical counterpart. If they exist, I'd love to hear about them.

[ducati]

Originally Posted by mikeo

Good questions, but the answers are months away. I'm curious how it will perform at autocrosses, where brake heating should not be a problem.

Maybe not: first drives should come VERY soon as the cars hit the hands of journos this week at Frankfurt :biggrin:

[335i=:)]

Don't forget you can't do donuts on concrete without one!!!! VIP

[Advevo]

I love to see movie of a doughnut with the 135i en see the ediff work.

I really want to buy a 135i but i have still ordered nothing.

I have a few questions before that

i want to test drive it first test a few things.

Will you be able to turn everything off and get one wheel spinning.

Will you be able to do doughnuts with the ediff. Not that i like doughnuts but then i can see if the the ediff works.

What will happen with youre brake pads when you join a driftday with the ediff.

I am still not convinced and if you can not change to a LSD because of the Ediff than i am not buying a 135i.

So bmw show us movie clips of full attack drifts with Ediff and a doughnut than i can place the order.