L.S.D, When, wut, why? Options

[Lil-Joe101]

Ok, so I see everybody talking and L.S.D.(Limited Slip Differential for those who are behind the curve) When would I need one and wut is the point of haveing one on a FWD car? I saw that TRD makes one for the 3sfe but I wanna know wut is the point of haveing one?

Can anyone answer this question for me?

Thanx

[BonzaiCelica]

would this lsd fit the st204. The celica gt.

http://www.horsepowerfreaks.com/partdetail...mited_Slip/1357

also for the description of the trd lsd it says this

The TRD mechanical LSD is 1.5-way clutch-type unit best suited for track use on modified vehicles. It can be switched to a 2-way configuration without any additional parts (except Vitz models). The 1.5-way is recommended for most users because the LSD functions strongly during acceleration, but is weaker when not accelerating preventing understeer going into corners. With the 2-way, the LSD functions strongly during engine deceleration, providing excellent vehicle control under a variety of conditions but requiring a bit more skill from the driver.

what does the stuff i highlighted in red and underlined really mean. if im driving normal with lsd it will be more difficult to turn. So it would be ideal not to have lsd while im using my car for daily driving?? im a bit confused on that. If anyone could clarify that for me i would appreciate it.

This post has been edited by BonzaiCelica: Jan 4, 2009 - 4:39 AM

[_Jim_]

would this lsd fit the st204. The celica gt.

http://www.horsepowerfreaks.com/partdetail...mited_Slip/1357

also for the description of the trd lsd it says this

The TRD mechanical LSD is 1.5-way clutch-type unit best suited for track use on modified vehicles. It can be switched to a 2-way configuration without any additional parts (except Vitz models). The 1.5-way is recommended for most users because the LSD functions strongly during acceleration, but is weaker when not accelerating preventing understeer going into corners. With the 2-way, the LSD functions strongly during engine deceleration, providing excellent vehicle control under a variety of conditions but requiring a bit more skill from the driver.

what does the stuff i highlighted in red and underlined really mean. if im driving normal with lsd it will be more difficult to turn. So it would be ideal not to have lsd while im using my car for daily driving?? im a bit confused on that. If anyone could clarify that for me i would appreciate it.

Basically, 1.5-way clutch type unit is only "activated" or truly "LSD" under load, or "hard" acceleration. So Basically when making a turn at normal speeds and not hammering the gas, the car WILL turn as nicely as a car with NON-LSD.....or open-diff. I can feel it when I go around a corner, anybody can. It is VERY noticeable. If I am going around a rotary and driving like I am supposed to, the car is fine. But if I push the car hard around the rotary I can feel the car wanting to "straighten out" more. Which makes total sense because when entering/making a turn, the outside wheel is spinning at a faster rate then the inside wheel, but when the LSD is "Active" both wheels want to rotate at the same pace/speed.

For example, think of a compass (the tool used to make circles, not the tool used for dictating north) So you set up your compass to make a 10inch circle. So you center pin is in the center of where you want to make your 10" circle, and you outside pin is 5"from there. Now make your circle. But instead of pins, imagine they were tires. The center pin/tire would actually not move at all, just kind of get pushed to follow the direction of the outside tire, but not actually rotating, still staying on the same spot where it contacted the groud before you started. But your outside tire is actually rotating/moving at a given speed. So for argument sake, call it 10mph, where your inside tire is actually moving at 0mph in order to accomplish this circle.

That is how an open diff works, and this was an extreme example to help visualize what I was saying. Now a 1.5-way LSD works identical to an open-diff when driven without load through a turn. Where as a 2-way LSD is much more aggressive. For lack of a better term, it is "always active," which makes turning a lot harder, and less "tight" (tight meaning the smallest circle that can be made by the same vehicle) A car with a open-diff and a 1.5way diff will essentially make the same "tight" circle when turning, where as a 2-way diff can not.

But as for "when" a LSD in "needed"....there really is no preset number because driver skill will play a big role at what power level the transfer from open-diff to LSD is made. But for your average driver.....If you plan on making over 200whp (and assumed associated torque is also around 200wftlbs, because that is the real problem when dealing with traction from a stand still) then I would say go with an LSD.

This post has been edited by _Jim_: Jan 15, 2009 - 11:19 AM