[mjh93sa]

Perhaps better to say that if you lock the wheels together too much then you will have trouble making the car turn as the wheels are being forced to turn at the same speed. the practical upshot of which can be chronic understeer as the front wheels cannot overcome the straight push generated by the rears.

Certainly Tony's diff seems to have a reasonable ballance from what I have seen whilst following. It still goes aroud corners very quickly indeed. Unfortunately I wasn't looking behind me when he was entertaining the locals whilst trying to keep up with me, but the reports are that it will go sideways in a nice correctable manner.

[E92Fan]

Originally Posted by creepy coupe

Good review E92, one questions, does it make the front try to push straight on when cornering?

No not at all - I agree with you that in theory it can make a car understeer more, but in this application I have yet to discover that, and I've driven it in almost all conditions now except for a track (which will be next April).

As far as noise goes, you can't hear the diff at all which again is suprising.

[E92Fan]

Originally Posted by nagge

How about driving in snow with the LSD? Will it get all tail happy?
Damn this sounds too good to be true

It shouldn't get tail happy if you know how to drive properly - that means, in snow, drive carefully! If you're clumsy with the gas, then sure the back will swing a little. The DSC system still works though, so it will be a bit of a help.

[dxb335d]

In my opinion it will create more oversteer than understeer now. Only If provoked of course. Instead of just the inside wheel spinning away both will hook up now!

[E92Fan]

Originally Posted by dxb335d

In my opinion it will create more oversteer than understeer now. Only If provoked of course. Instead of just the inside wheel spinning away both will hook up now!

Well that is true in so much that I can really control how the rear end responds - you really can adjust the cornering attitude with the throttle. It is how I imagine the car was designed in the first place, with a little extra power too, but was then down-specced to make room for the M3.

[dxb335d]

Originally Posted by E92Fan

Well that is true in so much that I can really control how the rear end responds - you really can adjust the cornering attitude with the throttle. It is how I imagine the car was designed in the first place, with a little extra power too, but was then down-specced to make room for the M3.

+1 i agree most definately!!


Least you can drift it like a pro now

[E92Fan]

Originally Posted by dxb335d

+1 i agree most definately!!


Least you can drift it like a pro now

we'll see how much of a difference it makes when I go 'Ringing next year. If I can get it close to 8:35 I'll be happy

[dxb335d]

Originally Posted by E92Fan

we'll see how much of a difference it makes when I go 'Ringing next year. If I can get it close to 8:30 I'll be happy

Yeah mate, let me know when ya going. I want to pack in a few trips there this year

[creepy coupe]

Originally Posted by dxb335d

In my opinion it will create more oversteer than understeer now. Only If provoked of course. Instead of just the inside wheel spinning away both will hook up now!

How can that be, if the inside wheel is going at the same speed as the outter, physics will come into play and naturally want the mass to countinue in a straigh line, if this isn't so evedent to be a problem, it sounds as if quaife have factured in some soft loading with a passenger car in mind.

Fair play to them, as thet's exactly what you want for road use.

£1200 sounds a bargin IMHO

[Serjames]

Don't confuse this with a 100% locked diff. It still has at least 30% bias i think to prevent the cornering issues you're describing.

SJ

[creepy coupe]

Originally Posted by Serjames

Don't confuse this with a 100% locked diff. It still has at least 30% bias i think to prevent the cornering issues you're describing.

SJ

I wasn't, I was going on the title of LSD "L" denoting not totally locked

[dxb335d]

They will hook up together, thats why it will slide better than with the stock diff.

[Serjames]

Originally Posted by creepy coupe

I wasn't, I was going on the title of LSD "L" denoting not totally locked

Sorry not aimed at you old chap, you posted before I finished typing

SJ

[creepy coupe]

Originally Posted by Serjames

Sorry not aimed at you old chap, you posted before I finished typing

SJ

Don't be, good thread this, interesting stuff.

[pdjafari]

would this mod do any benefit to a 335xi coupe?? Does the xi have anything specifically that would prevent install, or would an XI even need an LSD??? My G35 coupe had a LSD (sport package) but I never really could tell any benefits from having it vs not having it...

[E92Fan]

No, the XI doesn't need an LSD. It already has differentials in the drivetrain to apportion torque accordingly

[morten_m]

A great write up, and you describe my own experiences with the Quaife ATB LSD right on the nose.

[O-cha]

Originally Posted by mjh93sa

Perhaps better to say that if you lock the wheels together too much then you will have trouble making the car turn as the wheels are being forced to turn at the same speed. the practical upshot of which can be chronic understeer as the front wheels cannot overcome the straight push generated by the rears.

This is a torsen LSD it never "locks" the wheels, basically when one wheel spins faster in order to do so more torque has to be transmitted to the other wheel which must spin slower. This is a must and is how this type of differential works since it is purely a set of gears. Theres is never a lock like there is with a clutch type.

Of course it can be just as bad since its usually the inside wheel that loses traction while turning, which is also the wheel thats supposed to be turning slower, so in order for the torque to go to the outside wheel where there's traction the inside wheel has to spin faster.

Thats bad when your losing traction and trying to throttle into the corner (not to often), but it's better when leaving the corner.

[red-max]

Sorry if it's a dumb question, but will the fitting of an LSD have any detrimental affect on the fuel economy (assuming car is driven the same)? I'm tempted by an LSD for those occasions when it would be really handy (pulling out of a junction in the wet), but wouldn't want to cripple the excellent fuel economy of my 335d...

[E92Fan]

Originally Posted by red-max

Sorry if it's a dumb question, but will the fitting of an LSD have any detrimental affect on the fuel economy (assuming car is driven the same)? I'm tempted by an LSD for those occasions when it would be really handy (pulling out of a junction in the wet), but wouldn't want to cripple the excellent fuel economy of my 335d...

No, it has absolutely no effect on the fuel economy. Mine hasn't alterted one bit

[mjh93sa]

Originally Posted by O-cha

This is a torsen LSD it never "locks" the wheels, basically when one wheel spins faster in order to do so more torque has to be transmitted to the other wheel which must spin slower. This is a must and is how this type of differential works since it is purely a set of gears. Theres is never a lock like there is with a clutch type.

Of course it can be just as bad since its usually the inside wheel that loses traction while turning, which is also the wheel thats supposed to be turning slower, so in order for the torque to go to the outside wheel where there's traction the inside wheel has to spin faster.

Thats bad when your losing traction and trying to throttle into the corner (not to often), but it's better when leaving the corner.

Unless you are going off road or are into drfiting instead of cornering then you're never going to want a locked diff. What I was trying to do was to take the analogy of the LSD providing understeer by talking about the most extreme case.

If you want a little light reading on diffs you might want to take a look at http://www.houseofthud.com/differentials.htm

A quick point on Torsen diffs is that becasue they are TORque SENsing, they are absolutely no use when one whell is off the ground as there is no torque reaction to bring the diff into play. Not a problem for the likes of Tony or the E92 of course.

[E92Fan]

Also you must realise that the Quaife LSD only has a variable bias up to 80%. So it is never fully locked