Is a limited slip diff useful in a staight line?

[mazda2002]

I would like to know if a limited slip diff, like the one in the speed makes a considerable difference in acceleration in a straight line? (on a fast car)

 

[PFUNK5]

very much so, you have equal power going to the wheels, which means more traction too. LSD is very much needed if you wanna go forced induction, or performance driving.

 

[mazda2002]

I thought that as long as the wheels are perfectly straight, the power goes to both wheels?

 

[EvilMSP]

No my buddy in his Dodge Ram Hemi can do a 1 wheel burnout whenever he wants (he has no LSD or locker.)

 

[Pretzellogic]

Pegleg burnouts suck.

Yeah, an LSD makes a HUGE difference.

 

[tttP5]

sorry this is offtopic... do drifters need LSDs?

 

[Pretzellogic]

Okay, here it is:

A limited slip differential, in plain terms, delivers power to both wheels.

Yes, you need that for drifting, although you ain't going to be drifting a Protege anytime soon.

 

[mazda2002]

Is the limited slip in the mazdaspeed a clutch one?

 

[mazda2002]

Here is my little theory.
Trying to interpret this:
http://auto.howstuffworks.com/differential3.htm


If both wheels are straight with equal friction and you are on a flat surface, then both axle shafts turn at the same speed. If this is true, then both pinion gears have to be turning with the ring cage, but the won't be turning around the pinion shaft. So as long as the wheels are turning at the same speed and have the same traction (not buning out), there is equal power going to both wheels.

So I fugure that a limited slip diff would be more forgiving if you start to burn out, but wouldn't make any difference if your not.

Am I seing this all wrong?

 

[muohio]

Here is my little theory.
Trying to interpret this:
http://auto.howstuffworks.com/differential3.htm


If both wheels are straight with equal friction and you are on a flat surface, then both axle shafts turn at the same speed. If this is true, then both pinion gears have to be turning with the ring cage, but the won't be turning around the pinion shaft. So as long as the wheels are turning at the same speed and have the same traction (not buning out), there is equal power going to both wheels.

So I fugure that a limited slip diff would be more forgiving if you start to burn out, but wouldn't make any difference if your not.

Am I seing this all wrong?

You are right about if things are 100% perfect but that does not happen in real life. Also, both axles have to be equal length for things to be 100% and that is not the case on most cars and I think the Protege is in that boat. The '04 SRT-4 should a great improvement in traction with the LSD.

 

[apexlater]

if a car does not have an LSD the power leaving the motor will go to the path of least resistance, ie: the wheel that is spinning. FWD cars and mid/rear engine cars will also exhibit "torque steer" because the drive shafts are different lengths, so the side with the shorter drive shaft will have more power to it more quickly, hence pulling the car to that side.

An LSD senses when the wheel looses grip and diverts that energy to the wheel with traction. Under acceleration out of a corner an LSD puts most of the power to the outside wheel/tire that is loaded and off the inside "lighter" wheel/tire.

In a straight-line I imagine that the LSD will help alleviate torque-steer. I think that "drifters would certainly get an LSD so that they have better throttle control of the car....although a solid or welded rear diff. would accomplish the same thing, having equal power to both wheels.

 

[mazda2002]

Thanks for clearing that up for me

 

[changedman]

me wants lsd.

 

[Dimitrios]

if a car does not have an LSD the power leaving the motor will go to the path of least resistance, ie: the wheel that is spinning. FWD cars and mid/rear engine cars will also exhibit "torque steer" because the drive shafts are different lengths, so the side with the shorter drive shaft will have more power to it more quickly, hence pulling the car to that side.

An LSD senses when the wheel looses grip and diverts that energy to the wheel with traction. Under acceleration out of a corner an LSD puts most of the power to the outside wheel/tire that is loaded and off the inside "lighter" wheel/tire.

In a straight-line I imagine that the LSD will help alleviate torque-steer. I think that "drifters would certainly get an LSD so that they have better throttle control of the car....although a solid or welded rear diff. would accomplish the same thing, having equal power to both wheels.

Just note that a solid/welded axle isn't exactly the best for steering. An LSD allows both axles to spin at different speeds while going thru. a turn.

 

[apexlater]

That's true, I was thinking about RWD where you typically have equal length drive shafts. Our Spec Miata has the factory LSD, but if/when it goes out it becomes a solid diff....which buys time to get a new LSD, besides, if you're going to spin them, spin them both!

A solid diff. does create some interesting behavior since the wheels are trying to spin at the same rate but at different radiis.

 

[Mike R]

Even with equal length axle shafts, the right wheel will be the most likely to break loose because of the way the torque is distributed through the diff.

It's VERY useful. It was one of the first mods I did to all my RWD cars. Made nice dual marks on the pavement and made much better donuts.

 

[mazda2002]

Our Spec Miata has the factory LSD, but if/when it goes out it becomes a solid diff....

When the clutches burn out, they lock together? I would figure that they wouldn't have any effect anymore and react like a regular open diff?