Those who Purchased LSDs

[NYC6]

Originally Posted by John Dempsey

Im pulling the trigger on either a 3.46 quaife or a 3.08 wavetrack this week. Ill reply back after i do some driving.

please do. Im on the fence.

[int2str]

Originally Posted by Juicehead

For the guys who do not think it is needed for street use, are you stage 2+?

Yes

Originally Posted by Bmw135er

Another thing to consider for those of that do track the cars without an LSD. The e-lsd works okay, but not great. It cuts the power due to brake application, even in full dsc off mode.

Again, we're talking track use.

I've also never seen the car cut power. The car applies *some* braking to one of the rear wheels to create some drag. It doesn't stop the wheel completely, nor does it cut the power. See my video above and listen to the sound if you have any doubt about that.

engine output is limited. Or as I call it- limp **** mode, haha.

Never experienced this - neither during autocross (where the diff works much harder than on a big track), nor on the track.

The installation of a mechanical LSD all but eliminates the e-lsd function so brake temp induced limp **** mode is not occurring. Then you just have to worry about oil temps, but that's a whole separate issue.

Or diff temps. If you're managing to overheat your brakes that much with just "e-diff" action, then your diff oil is probably boiling at the end of the day.

Another factor in needing an LSD is suspension. If you're lowered, especially with coil overs or want to upgrade your sway bars, you'll need one. Even on a stock power level. Limiting wheel travel decreases traction in corners, whether its an autocross, road course or just an average road filled with twists.

Absolute BS.

Either your suspension is setup to make the car handle well, or it's set up to look awesome but work like crap. If your swaybars are oversized and your car is lowered all the way to the ground, it's not going to go around a turn no matter what diff you have.

Also, again, if you're driving on a road in a way that the e-diff can't handle it, you're doin' it wrong. This is again where I think a $60 autocross will do a lot more to make you smoother, faster and safer on the roads than hiding behind the "magical" attributes people give LSDs around here.

Once you add a tune on top of that, you're all in for an LSD if you want to use the power the car generates.

In most cases, the car isn't the limiting factor...

[Eyeman]

I like traction. The car I drove the most in my life was a 240hp Porsche with an incredible stock LSD and wider tires than on my One. It was very difficult to spin a tire under any circumstances with that car. To me a 400hp 135, especially with our limitations on tire sizes, definitely needs an LSD.

It is pretty neat though that those of us who use their cars on drag or road racing tracks usually get more improvement in track times by getting track specific tires than from installing an LSD.

[John Dempsey]

Well finally getting back to this I just installed my quaife LSD with the 3.46 ratio and it transformed the car. It's amazing

[icabod7]

John, please elaborate

[John Dempsey]

Originally Posted by icabod7

John, please elaborate

Well first off. The launches pull so much harder an are much crisper. There used to be an odd wiggle or one tire would break loose. Now it's just a crisp straight pull. Exiting corners there is much more grip and you don't have your inside wheel spinning. Also with it being 3.46 final drive instead of 3.08 the second and especially third gear pulls out of corners or in a straight line are much stronger. It never feels like it is hesitant to go. I'm full bolt on and I used to have bad traction issues and I really don't now.

[Sauce]

Originally Posted by int2str

Yes


Never experienced this - neither during autocross (where the diff works much harder than on a big track), nor on the track.



Or diff temps. If you're managing to overheat your brakes that much with just "e-diff" action, then your diff oil is probably boiling at the end of the day.



In most cases, the car isn't the limiting factor...

A diff will absolutely not work harder in an autocross than a road course. It will probably end up locking more, but the speed differential between the wheels won't be nearly as much. Also add to the fact the wheels themselves are going WAY slower ie: less inertia means that less force is needed to connect the two wheels together which means less work and heat. That's not even bringing in to the fact the autocrosses are a minute or two at low speeds rather than 20 at high speeds.

I smell the stupid E-diff killing pads all day on brake heavy courses.

I would not say that if the e-diff can't handle it your doing it wrong, however throttle control is a huge culprit of why people think they need an lsd. So I agree with you in a sense, but real track guys really do become limited by it.

When people play out the open diff to be dangerous it is so freaking annoying. If you are a bonehead and mash the gas with a bunch of steering angle at speed, you just hear the rpms rise and the car doesn't go anywhere nor does it fly sideways upside down like it's played out. It's just way more inefficient and unpredictable.

And let's be honest.. On this forum, the driver is ALWAYS the limiting factor.

[uberschnell]

Originally Posted by ianf

It improves the car a lot, and a must-have for track, but don't expect it to be on par with the diff in an ///M

Yes, god forbid you ever dare challenge the absolute superiority of the M

[uberschnell]

Originally Posted by ianf

True, what would I know after having a Quaife in my 135i and now an M

no one asked for the comparo, but

[TT1351]

Would do it again in a heartbeat.

[Dosturbos]

Even if you don't track your car, if you enjoy occasional aggressive street driving, you gotta get this mod. It is also awesome if you live somewhere with a harsher climate, like the northeast. I know I want all the traction I can get in rain or snow. It was my first mod. Your car will pull harder when launching and you will not see that silly DTC light come on as much. I got mine from Dan at diffsonline. I know he carries Quaife and wavetrac. I got the wavetrac done up for 2200 installed. I also got my car back in less than 5 hours!

[evilstib]

Originally Posted by ianf

It improves the car a lot, and a must-have for track, but don't expect it to be on par with the diff in an ///M

Why not?

[Venom]

Would it be possible to retrofit an ///M LSD into a 135i?

[Numbers]

Originally Posted by Juicehead

Would you do it again? I am about to pull the trigger.

I have the Quaife installed in my 135i. While it's not "necessary", it is probably the best mod to make. The car responds in a much more predictable manner as the rear can now be easily controlled (no more snap oversteer). The car is also infinitely better in the winter. Even with good snow tires, my car was little better than a toboggan in deep snow. With the LSD, it's now quite drivable.