is LSD needed? even on the race-track?

[Spoonie]

Can someone explain to me how a (LSD equipped) Z4 "M" coupe, got outperformed (slower lap times) by the heavier, less powerful, Non-LSD 335 Coupe? Seems like the LSD didn't do anything for the Z4 "M" LOL!

I'm glad that BMW didn't give the 135 a LSD. Judging from the performance of the LSD equipped Z4 vs the NON-LSD 335; the money was better off being spent elsewhere.

[Won35i]

LSDs are great for high hp cars and especially good for drifting. They are necessary, but can be useful in some applications, such as autocrossing.

[AchtungF80]

As he said, LSD is very helpful in and out of corners when powering out!! Definitely a handling difference.

[Spoonie]

Originally Posted by AchtungE30

As he said, LSD is very helpful in and out of corners when powering out!! Definitely a handling difference.

But does it (LSD) actually make the car go any faster? I think not.

When you have cars without an LSD beating lighter cars with LSD. I start to think that the LSD didn’t do anything for it in regards to speed.

[chemhalo]

Originally Posted by Spoonie

Can someone explain to me how a (LSD equipped) Z4 "M" coupe, got outperformed (slower lap times) by the heavier, less powerful, Non-LSD 335 Coupe? Seems like the LSD didn't do anything for the Z4 "M" LOL!

Horsepower sells cars. Torque wins races. Without a comparison graph prove it, the twin turbo N54 has much more area under the curve.

I bet a 335 w/ LSD would post an even faster lap time... and a Z4M with an open diff would post a slower time.

[bwanac]

in other news, very helpful in the snows.

[Won35i]

Originally Posted by Spoonie

But does it (LSD) actually make the car go any faster? I think not.

When you have cars without an LSD beating lighter cars with LSD. I start to think that the LSD didn’t do anything for it in regards to speed.

No it wont, can it make you push your car a little more in an autoX event, yes. If you know how to use it, then you can use an LSD to your advantage. It wont make your car reach a speed faster. All it is.... its a basic power converter. It switches the power from the wheel that is breaking loose to the wheel that has grip, potentially preventing understeer. Its not necessary for all cars. If you have a lead foot, well it wont help you very much.

[bradford]

Originally Posted by Won35i

It wont make your car reach a speed faster.

Anything that helps put more traction to the ground when there is ample power or cornering force to break traction will help "reach a speed" faster. (whatever that means)

Put simply, an LSD will make any given car faster on the track because you're able to translate engine power into forward motion as opposed to burnt rubber.

[Feli_330i]

I doubt the MZ4 is doing slower times than the 335i, maybe in the wet where that car is really tail happy ; even on the dry it is. The MZ4 is lighter and has more power not faster than the 335i on a track.

I think all BMWs should have an LSD, 15 years ago it used to be included not only in the M models but also cars with the sport package (i.e. 325is) the car behaves a lot better in the corners. Plus you can do awesome doughnuts

[larryn]

Two different drivers, and no word on track temps/conditions. 'Nuf said. The stock MZ4 would do damage to the stock 335i on the track with identical conditions.

The MZ4 has LSD and M suspension, plus is a lighter, more tossable car.

Don't be glad the 135i doesn't have one. I just put a locking diff in my car, and took seconds off autocross runs in the exact same car/tires/suspension.

[Propagator]

Originally Posted by Spoonie

Can someone explain to me how a (LSD equipped) Z4 "M" coupe, got outperformed (slower lap times) by the heavier, less powerful, Non-LSD 335 Coupe? Seems like the LSD didn't do anything for the Z4 "M" LOL!

I'm glad that BMW didn't give the 135 a LSD. Judging from the performance of the LSD equipped Z4 vs the NON-LSD 335; the money was better off being spent elsewhere.

There are so many variables in that comparison that there is no way in hell you can factor out the effect of the LSD, or lack there of. Of all things like torque, weight, type of the track, etc, LSD will be one of the more subtle variable.

And why would you be GLAD that an LSD is not offered even as an option? You don't have to get one, but that doesn't mean that no one should be able to.

[alex2364]

A LSD equipped car will almost always be faster than a identical non LSD equipped car. I think Spoonie is referring to the recent Car & Driver article where they brought a lot of different cars to a track including the 335i and Z4 M. Car & Driver said that the main reason why the Z4 M beat the 335i on the track is because the 335i is better balanced than the Z4 M.

[grant]

Originally Posted by Spoonie

I'm glad that BMW didn't give the 135 a LSD. Judging from the performance of the LSD equipped Z4 vs the NON-LSD 335; the money was better off being spent elsewhere.

That is an ignorant statement. I hope you'll be very happy with your standard sunroof which cost more than an LSD.

LSD is absolutely vital to an enjoyable driving experience in a high performance sportscar (just because a 335i is fast without one doesn't mean it wouldn't be faster and more FUN to drive with one). It was deleted for only one reason, to keep the 135i slower than more expensive BMW M models. Porsche does the same thing with its Cayman. It's shameful!

[imported_MPower]

Originally Posted by grant

That is an ignorant statement. I hope you'll be very happy with your standard sunroof which cost more than an LSD.

LSD is absolutely vital to an enjoyable driving experience in a high performance sportscar (just because a 335i is fast without one doesn't mean it wouldn't be faster and more FUN to drive with one). It was deleted for only one reason, to keep the 135i slower than more expensive BMW M models. Porsche does the same thing with its Cayman. It's shameful!

Totally agree (although I was expecting them to ignore a LSD option). To demonstrate the effect of a LSD, this is video done by Top Gear about the 535d (twin-turbo 3.0 litre straight 6 diesel). Watch what happens during the flying lap of their track going around the "hammerhead" (at around 7:55 in the clip). This is a classic example of what happens when you dont have a LSD:

[Won35i]

Originally Posted by alex2364

A LSD equipped car will almost always be faster than a identical non LSD equipped car. I think Spoonie is referring to the recent Car & Driver article where they brought a lot of different cars to a track including the 335i and Z4 M. Car & Driver said that the main reason why the Z4 M beat the 335i on the track is because the 335i is better balanced than the Z4 M.

:iono: The 335i beat the Z4 by 1.x seconds at VIR.

[Mahlzeit]

Here is a great description of what a proper LSD can do for you. Straight from the Quaife site.

http://www.quaifeamerica.com/differentials/diffs.htm

"
The Quaife Differential powers both drive wheels under nearly all conditions, instead of just one. With an ordinary open differential, standard on most cars, a lot of precious power is wasted during wheelspin under acceleration. This happens because the open differential shifts power to the wheel with less grip (along the path of least resistance). The Quaife, however, does just the opposite. It senses which wheel has the better grip, and biases the power to that wheel. It does this smoothly and constantly, and without ever completely removing power from the other wheel.

In drag-race style, straight-line acceleration runs, this results in a close to ideal 50/50 power split to both drive wheels, resulting in essentially twice the grip of an ordinary differential (they don't call open diffs "peglegs" for nothing).

In cornering, while accelerating out of a turn, the Quaife biases power to the outside wheel, reducing inside-wheel spin. This allows the driver to begin accelerating earlier, exiting the corner at a higher speed
"

That last bit means the car is more fun w/ and LSD if you like to drive hard.

-Mahlzeit

[Maximus Decimus]

Originally Posted by Spoonie

Can someone explain to me how a (LSD equipped) Z4 "M" coupe, got outperformed (slower lap times) by the heavier, less powerful, Non-LSD 335 Coupe? Seems like the LSD didn't do anything for the Z4 "M" LOL!

I'm glad that BMW didn't give the 135 a LSD. Judging from the performance of the LSD equipped Z4 vs the NON-LSD 335; the money was better off being spent elsewhere.

Little bit of a short sighted post. Different tracks bring out different strengths in different cars. At a different track the results could have been COMPLETELY different. In that same article the 335i was a 2nd quicker than an RS4. I guess all the RS4 owners should go demand their money back and get a 335i??? I consider myself a huge BMW supporter and the thought of that is pretty laughable. Magazine test results should never be taken as gospel.

MPower and Mahlzeit, thanks for those posts. Hopefully it helped to open some eyes.

[mikeo]

I have nothing to add except agreement with MPower and Mahlzeit. The OP obviuosly has not owned a car with with LSD (or driven it hard enough to see the benefit).

[Spoonie]

Originally Posted by bradford

Anything that helps put more traction to the ground when there is ample power or cornering force to break traction will help "reach a speed" faster. (whatever that means)

LSD doesn't "put more traction to the ground ". It just maximizes the available traction.

[Propagator]

Originally Posted by Spoonie

LSD doesn't "put more traction to the ground ". It just maximizes the available traction.

Oped diff will send more power to the wheel that is slipping. This will further reduce the grip on that wheel, thereby reducing the total amount of traction available to the car. So yeah, you CAN get more traction from LSD in many cases.

[Won35i]

How is it so hard to understand that it switches power from the wheel that slips to the wheel that grips temporarily until it sense no slipping.

[imported_Sweeper]

LSD makes you talk about stuff you know nothing about on the internet....:drinking: