someone learn me on LSD's

[slaytalera]

{noob mode}
ok, im wanting to get front and read LSD's for the outback, ATM im running 4eat, but ill soon have a jdm 5 speed. as i understand it, the jdm 5 speeds come with a VLSD in the rear. what advantages would there be by going to a clutched diff, and what does 1.5 and 2 way mean?
{/noob mode}

[jey]

http://en.wikipedia.org/wiki/Limited_sl ... l#Benefits (http://en.wikipedia.org/wiki/Limited_slip_differential#Benefits)

[ouch1011]

Well, the transmission and the rear differential are 2 different things. So a JDM transmission won't come with a rear limited slip diff.

A Viscous limited slip diff (or VLSD) is a very, very mild LSD usually found in GT cars. It gives some of the benefits of an LSD without being clunky or noisy around corners like CLSDs can be. Downside is that a VLSD is reactive, not proactive. Meaning that there has to be a fairly considerable difference in wheel speed side to side before the LSD will even attempt to equalize the wheel speed. And even then, because there is no mechanical connection between the 2 wheels, it is very easy to overpower a VLSD and cause a difference in speed. For instance, the center diff in pretty much all the 5-spds (aside from those with DCCD) have a viscous center diff. If you watch a Subaru with a 5spd do a drag launch, usually the front tires do a burnout before the car really takes off. This is because the VLSD acts like an open diff at first and goes to the path of least resistance (the front tires) until the viscous fluid heats up and tries to equalize the speed front to rear.

A clutched LSD makes an actual mechanical connection between the 2 sides of the differential, and they are usually activated by the force of the diff side gears pushing against the diff case when power is transmitted to it, so the force equalizing the speed between the 2 sides increases with the amount of force being applied to the diff, and it happens immediately. Some CLSDs are preloaded as well, so they will equalize wheel speed even when no force is being applied to the wheels. This is better for situations where there is a large difference in traction between the 2 wheels. Downside is that CLSDs can be noisy when doing tight turns and can be borderline dangerous for inexperienced drivers because a rear CLSD will make the car tend to oversteer under power, possibly unpredictably, especially in bad weather. A CLSD in the front will make the car torque steer.

The 1.5 way and 2 way have to do with how the diff clutches are applied and changes how it responds under power versus under coasting.

[mike-tracy]

Noob question then... :smile:
How about the STI's R180, what would it take to fit it to our cars? STI specific axles, hubs, etc?

[slaytalera]

Well, the transmission and the rear differential are 2 different things. So a JDM transmission won't come with a rear limited slip diff.

A Viscous limited slip diff (or VLSD) is a very, very mild LSD usually found in GT cars. It gives some of the benefits of an LSD without being clunky or noisy around corners like CLSDs can be. Downside is that a VLSD is reactive, not proactive. Meaning that there has to be a fairly considerable difference in wheel speed side to side before the LSD will even attempt to equalize the wheel speed. And even then, because there is no mechanical connection between the 2 wheels, it is very easy to overpower a VLSD and cause a difference in speed. For instance, the center diff in pretty much all the 5-spds (aside from those with DCCD) have a viscous center diff. If you watch a Subaru with a 5spd do a drag launch, usually the front tires do a burnout before the car really takes off. This is because the VLSD acts like an open diff at first and goes to the path of least resistance (the front tires) until the viscous fluid heats up and tries to equalize the speed front to rear.

A clutched LSD makes an actual mechanical connection between the 2 sides of the differential, and they are usually activated by the force of the diff side gears pushing against the diff case when power is transmitted to it, so the force equalizing the speed between the 2 sides increases with the amount of force being applied to the diff, and it happens immediately. Some CLSDs are preloaded as well, so they will equalize wheel speed even when no force is being applied to the wheels. This is better for situations where there is a large difference in traction between the 2 wheels. Downside is that CLSDs can be noisy when doing tight turns and can be borderline dangerous for inexperienced drivers because a rear CLSD will make the car tend to oversteer under power, possibly unpredictably, especially in bad weather. A CLSD in the front will make the car torque steer.

The 1.5 way and 2 way have to do with how the diff clutches are applied and changes how it responds under power versus under coasting.

it will be coming with a VLSD, i know what im buying.


and thank you for the info, what are quaife(sp?) LSDs?

[jey]

Quaife is just a company that makes a lot of differentials - most popular for their mechanical helical designs.