[abhishriv]

im on the fence about buying an LSD... i mean i DO want to buy it. but cant decide if i should do it now or wait until spring... are there any benefits of me getting it now as opposed to later?

[jpsimon]

The main benefit of getting it now is that you can use it now. But if you wait, you won't have it now and you'll have to get it later.

How often do you drive in the snow? Do you daily drive your non-xi in the winter?

[abhishriv]

Originally Posted by jpsimon

The main benefit of getting it now is that you can use it now. But if you wait, you won't have it now and you'll have to get it later.

How often do you drive in the snow? Do you daily drive your non-xi in the winter?

yes i daily drive my car. i have driven my car through a couple winters now.

[Wedge1967]

Spend the money on a winter bomber, then sell it in the spring so you can buy the LSD. Save the coupe for a sunny day! without snow...

[abhishriv]

Originally Posted by Wedge1967

Spend the money on a winter bomber, then sell it in the spring so you can buy the LSD. Save the coupe for a sunny day! without snow...

wouldnt really work out for me, dont have the space for another car, dont want to put up with the hassle of paying for a beater and then having to sell it in spring, also dealing with insurance in canada isnt easy. and lastly, i enjoy my car to the fullest and love driving it in winter

[Wedge1967]

Yeah, don't blame you one bit. But an older AWD rally car would be fun in the snow...

Good luck....

Originally Posted by abhishriv

wouldnt really work out for me, dont have the space for another car, dont want to put up with the hassle of paying for a beater and then having to sell it in spring, also dealing with insurance in canada isnt easy. and lastly, i enjoy my car to the fullest and love driving it in winter

[ajm8127]

I'm in the same boat that you are. I was thinking of just getting the LSD now and having it for winter. I figure it can't hurt. How has your car been in previous winters? I suspect you have used snow tires; any notable traction problems above and beyond the normal winter slipping.

On a side note, people claim that the Quaife can't perform in the winter because if it encounters a zero traction event, it cannot bias any torque to the other side. In the event you are slipping on snow or ice, you would probably have at least DTC enabled which would apply the brakes to the slipping wheel, allowing the Quaife to bias torque to the other side. So there is no issue with the Quaife in the winter with the 335i, and any LSD certainly will not be worse than an open differential. The only problem would be with the driver.

[abhishriv]

Originally Posted by ajm8127

I'm in the same boat that you are. I was thinking of just getting the LSD now and having it for winter. I figure it can't hurt. How has your car been in previous winters? I suspect you have used snow tires; any notable traction problems above and beyond the normal winter slipping.

On a side note, people claim that the Quaife can't perform in the winter because if it encounters a zero traction event, it cannot bias any torque to the other side. In the event you are slipping on snow or ice, you would probably have at least DTC enabled which would apply the brakes to the slipping wheel, allowing the Quaife to bias torque to the other side. So there is no issue with the Quaife in the winter with the 335i, and any LSD certainly will not be worse than an open differential. The only problem would be with the driver.

ive decided to go ahead with it now.. been reading that LSD can certainly help in winter with acceleration but to obviously be careful, as now you will be able to spin both wheels rather than just one. my car was ok in the snow with winter tires, you have to have common sense. the main problem i found before was traction from a stand still, one wheel would spin and then the rear of my car would go slide to the side while standing still. i think LSD and some weight in the trunk should take care of that.

[ajsalida]

Originally Posted by abhishriv

ive decided to go ahead with it now.. been reading that LSD can certainly help in winter with acceleration but to obviously be careful, as now you will be able to spin both wheels rather than just one. my car was ok in the snow with winter tires, you have to have common sense. the main problem i found before was traction from a stand still, one wheel would spin and then the rear of my car would go slide to the side while standing still. i think LSD and some weight in the trunk should take care of that.

I don't understand, do you not have traction control? I understand the advantage of a mechanical LSD on dry pavement + high power but in winter and on snow/ice the e-diff/DSC/DTC system should be enough.

I do not see how you can spin one wheel with DTC or DSC either enabled or disabled, on snow/ice (e-diff is always on). Both wheels with DTC on or DSC full off, yes, but one wheel, no. But then an LSD won't help in that situation.

Maybe I am wrong help me out. I have an Xdrive and it spins all 4 wheels with DTC on or DSC full off on ice.

edit: a RWD car with LSD and improper tires will still just sit there and spin both its rears on ice, and slide sideways. Snow tires are a must and some weight of course helps.

[JamesM3M5]

Winter traction on a modern DSC equipped car is helped most by TIRES, not a diff. Get winter tires and wheels from 1010tires.com (Candian company). Then in the spring get the LSD for dry traction.

[abhishriv]

Originally Posted by JamesM3M5

Winter traction on a modern DSC equipped car is helped most by TIRES, not a diff. Get winter tires and wheels from 1010tires.com (Candian company). Then in the spring get the LSD for dry traction.

already have winter tires, thanks.

[abhishriv]

Originally Posted by ajsalida

I don't understand, do you not have traction control? I understand the advantage of a mechanical LSD on dry pavement + high power but in winter and on snow/ice the e-diff/DSC/DTC system should be enough.

I do not see how you can spin one wheel with DTC or DSC either enabled or disabled, on snow/ice (e-diff is always on). Both wheels with DTC on or DSC full off, yes, but one wheel, no. But then an LSD won't help in that situation.

Maybe I am wrong help me out. I have an Xdrive and it spins all 4 wheels with DTC on or DSC full off on ice.

edit: a RWD car with LSD and improper tires will still just sit there and spin both its rears on ice, and slide sideways. Snow tires are a must and some weight of course helps.

im not saying that the stock open differential is useless in winter (ive been through 2 winters already just fine), but i was wondering if the LSD would be BETTER or if there are any draw backs to having an LSD on slippery roads. my main problem with the open diff is with the start from a stand still, one wheel will initially spin and then the e-diff will brake on that wheel and send the power to the other.. the problem ive noticed here is that if both tires have little grip, the e-diff will just keep switching back and forth between the rear wheels and drastically reduce the engine speed, which makes for a very twitchy and slow start (yes i know just an LSD would prove to be no better in this situation, but paired with good winter tires?). ive read from many LSD owners that their new diffs helped in this situation. Winter tires are the most important, i agree, thats why they were my first purchase before any mod i did to this car.

[JamesM3M5]

If you were to do a limited slip that helps the most in very low traction situations, it would need to be a Salisbury style limited slip (clutch packs), not a torque-biasing diff. I've driven BMWs in snow for years, all with factory salisbury limited slip when it was available back in the 80s and 90s. Quaifes don't help at all in those situations, and they equally suck in the dry on a road course for a RWD car.

I am saving up for a real limited slip when the time comes next Spring - Dan at Diffsonline builds the best racing and street diffs for BMWs. No Quaife, no Wavetrac, just a real, honest asymetric lockup Salisbury limited slip. Cheaper than a Drexler, too.

[cstavaru]

Originally Posted by abhishriv

im on the fence about buying an LSD... i mean i DO want to buy it. but cant decide if i should do it now or wait until spring... are there any benefits of me getting it now as opposed to later?

Don't miss the opportunity of doing donuts in the parking lot this winter. Get the LSD

[ajsalida]

OP, have you run with DTC in snow/ice? Or with DSC full off? You should be able to spin both rears in low traction situations without engine cutting out. Even with the OEM clutch-type LSD on my old e36 M3, each side grabs a little unevenly depending on traction, with both spinning.

As to downsides of LSD, at least with clutch type you'll get the inside rear wheel dragging on off-throttle turn in, so rear steps out a bit as you let off and turn in. It is fun if you like that sort of thing but maybe it is nerve wracking to others. Good for initiating donuts.

I do not know if this happens with qaiffes or wavetracs, never had one of them. I really don't think you get much benefit from adding an LSD to an e9x for winter driving. You would if you had an open diff and no e-diff.

[JamesM3M5]

Originally Posted by ajsalida

As to downsides of LSD, at least with clutch type you'll get the inside rear wheel dragging on off-throttle turn in, so rear steps out a bit as you let off and turn in. It is fun if you like that sort of thing but maybe it is nerve wracking to others. Good for initiating donuts.

You would have to have some seriously screwed up diff lockup to do that. Sounds like bad alignment, too much rear bar, or some other problem. There is no way a Salisbury LSD will cause that.

Too much rear lockup causes corner entry understeer, not wheel dragging or oversteer. Tuning the dynamic lockup under decel or overrun helps keep the rear inline, especially on these newer cars with huge rear brakes controlled with electronic brake force distribution.

[ajsalida]

Originally Posted by JamesM3M5

You would have to have some seriously screwed up diff lockup to do that. Sounds like bad alignment, too much rear bar, or some other problem. There is no way a Salisbury LSD will cause that.

Too much rear lockup causes corner entry understeer, not wheel dragging or oversteer. Tuning the dynamic lockup under decel or overrun helps keep the rear inline, especially on these newer cars with huge rear brakes controlled with electronic brake force distribution.

Maybe semantics here. On pavement, not at the limit, sure, I agree. This is on ice. It pushes a little initially but once the front loads up & bites it turns & the inside rear lets go. You can feel it go, and then the rear steps out. Another way to say it is sometimes you have to break the inside rear loose to turn.

Nothing wrong with the diff or alignment, but on ice it behaves a little like a locked diff does at the limit on pavement is all. Have had several cars with clutch LSD and they all did this in winter. Currently an e36 m3 in addition to the 335xi (e-diff). Plus a 4x4 truck with e-locker. And used to have a ITB 2002 with welded diff.

Point is a clutch diff on ice on corner entry will behave like it has too much lock up. OP was asking for downsides in winter, this is not one IMHO but some might be surprised by it.

edit: WRT to sway bars, up here in the mountains where I live at least, many folks disconnect bars for winter, cause any bar at all is too much bar on ice or hard pack snow.

[ajm8127]

OP, what LSD are you looking at; probably the Quaife or Wavetrac, right?

I don't think the OP is looking for an LSD solution to help with low traction issues in the winter. I think primarily he wants it for dry weather spirited driving, but is interested in the effects it will have in the winter because the car is a DD. He lives in Toronto, and will be using snow tires like a sensible person.

http://www.1addicts.com/forums/showthread.php?t=453632

This guy has nothing but good things to say about the Quaife in snow. He seems very pleased with the level of control he has over the car. The last post is about how the Quaife has "no downsides." This is posted in July, and he had the diff installed before the previous winter. Sounds like snow or not, ran or shine, he is pleased with the Quaife and thinks it had a positive effect in all driving conditions.

I suspect results with the Wavetrac would be very similar.

[abhishriv]

Originally Posted by ajm8127

OP, what LSD are you looking at; probably the Quaife or Wavetrac, right?

I don't think the OP is looking for an LSD solution to help with low traction issues in the winter. I think primarily he wants it for dry weather spirited driving, but is interested in the effects it will have in the winter because the car is a DD. He lives in Toronto, and will be using snow tires like a sensible person.

http://www.1addicts.com/forums/showthread.php?t=453632

This guy has nothing but good things to say about the Quaife in snow. He seems very pleased with the level of control he has over the car. The last post is about how the Quaife has "no downsides." This is posted in July, and he had the diff installed before the previous winter. Sounds like snow or not, ran or shine, he is pleased with the Quaife and thinks it had a positive effect in all driving conditions.

I suspect results with the Wavetrac would be very similar.

thanks! yup you got it exactly right. im not buying LSD for winter specifically, im looking to buy one mainly for next spring and summer because i want to track, and was wondering if theres any downsides to getting it before winter hits since I can get a reasonable price right now. thanks for the find, im going with a wavetrac.