LSD

Have one of these in my Z4C.
Don't really know how the car drove without it as I bought it this way.
Works fine for me, though.
 
Makes a massive difference to the E85/6 so imagine the impact on the E89 would be just as good. Literally transforms the car.
 
To be perfectly honest, I don't think it'll make quite the transformative difference envisaged when compared to an E85. The E89 has a torque vectoring system that applies the brake to the spinning wheel, forcing power to go the the one with traction, simulating an LSD. It isn't as reactive as a proper differential, but is effective and consistent.
 
Player 1 said:
To be perfectly honest, I don't think it'll make quite the transformative difference envisaged when compared to an E85. The E89 has a torque vectoring system that applies the brake to the spinning wheel, forcing power to go the the one with traction, simulating an LSD. It isn't as reactive as a proper differential, but is effective and consistent.
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I don't know myself, hence my questions, and they would say that wouldn't they, but Bird's who do all BMW Quaife LSDs say..
http://www.birdsauto.com/sites/default/files/pdfs/E9233928336.pdf :thumbsup:
 
Pbondar said:
Player 1 said:
To be perfectly honest, I don't think it'll make quite the transformative difference envisaged when compared to an E85. The E89 has a torque vectoring system that applies the brake to the spinning wheel, forcing power to go the the one with traction, simulating an LSD. It isn't as reactive as a proper differential, but is effective and consistent.
Click to expand...

I don't know myself, hence my questions, and they would say that wouldn't they, but Bird's who do all BMW Quaife LSDs say..
http://www.birdsauto.com/sites/default/files/pdfs/E9233928336.pdf :thumbsup:
Click to expand...

They do touch on the simulated LSD in the article calling it inefficient. Though as you say, they would say that!
Have you ever tried to powerslide both an E85 and an E89? I have and while the open diff in the E85 makes it barely controllable and frankly downright dangerous, the E89's simulated differential makes it easy to hold a slide, increase it with extra throttle or straighten up with less throttle.
Having also tried numerous other cars with proper limited slip differentials, I don't think there's much in it between the simulated LSD and a proper one in an oversteer situation once the car is sideways. Just as it starts to go however, a proper LSD is noticeably quicker to react whereas in the E89 there's something of a will it/won't it 'pause' before settling into a slide, sorry if that sounds a bit vague as it's hard to describe and the moment must only last a few hundredths of a second! Once you learn to trust the system however it soon feels normal.
(All conducted on private grounds, of course!)

In a standing start, I could see there being a definite advantage to a LSD opposed to the virtual one as applying brakes can only be slower than a clutch diverting power. Personally, this isn't really something I'd be too worried about as I've far too much mechanical sympathy to dump a clutch in any car and nail it :cry:

I should say, I'm not trying to knock Quaife's product. They do make very good differentials and it'd be an upgrade over the virtual one for sure. I just don't think it'd be such a big difference as it is when going from a car with an open differential and no vectoring, as it is in the E85.
 
Player 1

Well, I have to confess that my testicles are not as full as they used to be, plus years on motorbikes, which translates into: I normally don't try and provoke the Z4 to break traction, I wait till I'm well past the apex before flooring it..

With only 280BHP and sticky Continental Sport tyres I'm not sure whether you can make it brake traction on a dry road once its rolling..

I agree that modern electronics do a great job, just can't resist twiddling with my favourite toy..

Since I won't be going for a 35i(s) I'm limited to just 280 BHP, so have to make up for it by going around the corners faster..

Your observations are illuminating.. I do these tricks in the snow at low speed..but not on tarmac at higher speed..private testing areas exempted! :rofl:
 
I have to say, I do like the look of your car :D If twiddling is of interest, for much less cost than the differential and a result that's far more relevant to normal, enjoyable driving. May I suggest robbing the E90 series M3 for suspension parts? Here's my thread on doing so:
https://z4-forum.com/forum/viewtopic.php?f=23&t=108512
(Will go very well indeed with your roll bars)

Apologies for being somewhat off topic!
 
Player 1 said:
I have to say, I do like the look of your car :D If twiddling is of interest, for much less cost than the differential and a result that's far more relevant to normal, enjoyable driving. May I suggest robbing the E90 series M3 for suspension parts? Here's my thread on doing so:
https://z4-forum.com/forum/viewtopic.php?f=23&t=108512
(Will go very well indeed with your roll bars)


Apologies for being somewhat off topic!
Click to expand...

Yes I looked at it, but the issue on the bracket for the headlamp sensor threw me..I don't have proper facilities at home eg ramp / jacks /proper garage so rely on my tame local garage, where I'm into simple swaps not fabrications etc..otherwise maybe..

I have to say with the H&R roll bars and the B8 shocks on existing MSport springs and 235/40 17 front tyres it handles very very nicely on my private proving ground from Moffat to Selkirk! :driving:
 
tintoverano said:
I don't want to hijack the "true M car" thread, so opening this one since LSD is coming up there frequently

has anybody considered this or any other similar solution: Quaife BMW Z4 ATB https://shop.quaife.co.uk/quaife-bmw-z4-atb-differentials?
Click to expand...

Putting a Quaife LSD in a non-LSD car is expensive. Not to mention you will probably lose most of that money come resale.

Unless you’re drifting/tracking the car I really wouldn’t bother.
 
Player 1 said:
Have you ever tried to powerslide both an E85 and an E89? I have and while the open diff in the E85 makes it barely controllable and frankly downright dangerous, the E89's simulated differential makes it easy to hold a slide, increase it with extra throttle or straighten up with less throttle.
Having also tried numerous other cars with proper limited slip differentials, I don't think there's much in it between the simulated LSD and a proper one in an oversteer situation once the car is sideways.

In a standing start, I could see there being a definite advantage to a LSD opposed to the virtual one as applying brakes can only be slower than a clutch diverting power. Personally, this isn't really something I'd be too worried about as I've far too much mechanical sympathy to dump a clutch in any car and nail it :cry:
Click to expand...
Says he sideways in his E89 with the computers and brakes desperately try to keep it all looking cool and in control. :driving: :wink:
 
buzyg said:
Player 1 said:
Have you ever tried to powerslide both an E85 and an E89? I have and while the open diff in the E85 makes it barely controllable and frankly downright dangerous, the E89's simulated differential makes it easy to hold a slide, increase it with extra throttle or straighten up with less throttle.
Having also tried numerous other cars with proper limited slip differentials, I don't think there's much in it between the simulated LSD and a proper one in an oversteer situation once the car is sideways.

In a standing start, I could see there being a definite advantage to a LSD opposed to the virtual one as applying brakes can only be slower than a clutch diverting power. Personally, this isn't really something I'd be too worried about as I've far too much mechanical sympathy to dump a clutch in any car and nail it :cry:
Click to expand...
Says he sideways in his E89 with the computers and brakes desperately try to keep it all looking cool and in control. :driving: :wink:
Click to expand...

A gentle slide and smashing maximum torque through the driveline in an instant are very different things :rofl:
 
R60BBA said:
Putting a Quaife LSD in a non-LSD car is expensive. Not to mention you will probably lose most of that money come resale.

Unless you’re drifting/tracking the car I really wouldn’t bother.
Click to expand...

I think that a Quaife diff holds it's value better than the average car..... :lol:
 
GuidoK said:
R60BBA said:
Putting a Quaife LSD in a non-LSD car is expensive. Not to mention you will probably lose most of that money come resale.

Unless you’re drifting/tracking the car I really wouldn’t bother.
Click to expand...

I think that a Quaife diff holds it's value better than the average car..... :lol:
Click to expand...

Lol that’s not saying much. :rofl:
 
It says enough that when you sell your car, that selling the lsd will be far more easier.
You see that all the time on forums when someone is going to sell a tuned car.... nobody wants the car but everyone wants the BBK or KW clubsports or LSD or Supercharger kit or whatever goodies are on there.

Imho it's one of the best mods you can do to your car. At least if you use your car as a sportscar.
I also think its more useful for hooning around on canyon roads/mountain passes etc than on a track
 
An LSD is less safe/predictable on rear end step outs on wet surfaces.
This might sound strange, but with an open diff, the chance that only the inner wheel is spinning (for instance when pulling away from a traffic light in the wet in a corner) is much greater than with an LSD (because thats what an LSD prevents).
Now, as long as your inner wheel is spinning, that means that there is no or less foreward torque (as it all gets wasted on that inner wheel), and the outer wheel always has grip. So no step out.

Of course WITH an LSD, you prevent that inner wheel spinning. Therefore you have more foreward traction in those conditions and you will be FASTER. But when you loose traction, it will step out, and you'll be going faster when that happens.

Therefore I always advise to leave traction control and esp on when driving in the wet/on potential slippery surfaces (that can also be dry with for example beach sand on the road), unless you are aware of this and actively want to play around a bit.

So imho an LSD is a performance option, not a safety option. Driving with an LSD requires more skill from the driver. Because you can go faster.
So an LSD is for drivers who are constanly annoyed by the traction control cutting in when driving over manhole covers, tight corners, traffic lights etc. So people with a certain driving style... :lol: :evil:
 
I owned multiple BMWs with and without Quaife LSDs (330ci and Z4 35i). I have personally found the open diff a lot more unpredictable. The "ediff" comes in abruptly and aggressively (breaking one wheel) which is either enough to kick the end out violently for a split second or does absolutely nothing. The helical LSD that Quaife does never locks and distributes power continuously depending on grip levels, ensuring maximum traction. I have found it extremely predictable, with the rear end losing grip very gradually when applying too much power. If you are pushing a Stage 1+ map, you'll find it very difficult to put power down in 1st, 2nd and sometimes 3rd (wet) gear without an LSD.

I think the LSD is a must for any RWD cars pushing over 250bhp (provided you like to slingshot out of corners, junctions, roundabouts etc.). If you are a chilled out driver, it won't make any difference.. but then you might as well drive a Micra :P

One thing I'd say is that unless you have manual trans, forget "drifting" even with an LSD. The auto/DCT box is great but awful for low-speed fooling around.
 
GuidoK said:
It says enough that when you sell your car, that selling the lsd will be far more easier.
You see that all the time on forums when someone is going to sell a tuned car.... nobody wants the car but everyone wants the BBK or KW clubsports or LSD or Supercharger kit or whatever goodies are on there.

Imho it's one of the best mods you can do to your car. At least if you use your car as a sportscar.
I also think its more useful for hooning around on canyon roads/mountain passes etc than on a track
Click to expand...

I don’t dispute that.

Selling the LSD shouldn’t be an issue.

My point was more referring to the labour costs of getting a mechanic to install and remove the LSD, outweighing the difference it would make on the road.

Changing the diff on a car requires mechanical knowledge, it’s not a DIY job and I highly doubt the average Z4 owner is a mechanic or knows how to competently to this job. *However if you are mechanically minded and can do this job then there’s no need to read further.*

Birds, Isleworth (who practically make a living out of this) quote 4 hours just to install a Quaife, and then another 4 hours to remove it. The average BMW independent charges £90 an hour. Thus, 8 hours of labour at £90 = £720. That is £720 which you won’t get back. Not to mention you will lose a couple hundred quid on the LSD itself come re-sale. All in you’ve already lost a grand, and for what? Just so that you can have more controllable skids at roundabouts? It’s not like these are 500+ bhp cars which struggle with putting the power down in a straight line either.

An LSD swap is 100% not worth it if the car’s power output is not going to be significantly increased or if it is not going to be put on track.

“If you want the LSD, just buy the M.” :thumbsup:
 
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