jeffreylin

I am about to build a new car (FW-05R) and cannot decide to use the LSD gears or not in the rear diff.

I think it gives you a lot of accleration out of corner but it also pushes under power.

What do you all think? worthwhile trade-off or not?

If I were to use the LSD, what weight of oil will you recommend so that it does not lock up too easily?

Thanks!

rjl

Are you talking about the TCD, Active diff, Negative diff? If it's the TCD then use the fluid supplied or torsen diff fluid. My own experience with the TCD is that I seemed to have better on power control over the rear end of the car, more progressive.

jeffreylin

I am talking about the TCD gears. I did try the fluid provided but it is so light and seems to lock up easily. Once it lock up, the car goes nowhere but straight forward. I was told that using a heavier oil will prevent the gears to lock up so easily.

rjl

When new the diff may feel a bit notchy but shouldn't lock up ever. Use the fluid that came with the diff and fill as per the instructions none of mine ever "locked".

jeffreylin

My understanding of limited slip differential is that it is suppose to provides a certain amount of slip before it locks up. It works much like a normal diff but will lock up when one wheel spins much faster than the other or under full power. When it "locks up," the rear is essentially working like a spool, thus the understeer.

rjl

The resistance increases but it won't lock.