I tried searching but couldn't find a definite answer!

I know that the Toms Lsd is out there, but is it applicable to the USDM IS?

Would it be hard to install the TOMs LSD?

does the TOMs LSD locks the diff. and make the both rear tire spin at the same time?

Are there more brand LSDs available for the IS?

Thanks in andvance!
this site is the best!

 

I believe it does it if my memory serves me it is just a 1 way LSD

 

/\ Tom's diff is a one way unit- and is very pricey, does not matter if its usdm or any other market- I have been wanting to put in a diff for a while and have not had much luck with finding anything other than the Tom's unit.
According to a post from Lobux june of last year the is250 rwd was equiped with a torsen lsd from the factory (let the salvage yard search begin!).
And also apparently the canadian sport pack is350's got one too?

 

it was optional on the IS250 RWD. But the gear ratio is different between the 250 and 350

 

Swapping a ring and pinion gear is not hard....

 

might lose drive ability.

 

So I acquire an optional is250 torsen rear diff, swap it in to my 350 using my original ring and pinion gear maintaining the same final drive ratio...

How do I lose "drive ability"?

 

since your 350 has VDIM it might act funny in different driving situations unless you turn it off.

That is what i remember from a old post.

 

1 way LSD? Can someone explain this?

 

this is from wikipedia

"If there is no additional coupling on over run, the LSD is 1 way. This is a safer LSD, as soon as the driver lifts the throttle, the LSD unlocks and behaves somewhat like a conventional open differential. This is also the best for FWD cars, as it allows the car to turn in on throttle release, instead of ploughing forward. [1]

If the LSD increases coupling in the same way regardless of whether the input torque is forwards or reverse, it is a 2 way differential. Some drifters prefer this type as the LSD behaves the same regardless of their erratic throttle input, and lets them keep the wheels spinning all the way through a corner. An inexperienced driver can easily spin the car when using a 2 way LSD if they lift the throttle suddenly, expecting the car to settle like a conventional open differential.

If the LSD behaves somewhere in between these two extremes, it is a 1.5 way differential, which is a compromise between sportiness and safety"

My Z28 is a 2way because of a special order when it was built at the factory. FYI I am running a 4.10 Auburn diff.

 

How can you tell if my 250 has it or not? What is the option to look for? If mine does not, anyone know the Torsen part # for the lsd?

 

The part # for the optional torsen diff on the 250 is FX20TX (per Lobux).
My hope is that the addition of the torsen diff would make VDIM less intrusive since it uses brake and throttle cut to counteract differing wheel speed (wheel spin) at the rear end.
The whole point of an LSD is to put more power to the ground through both drive wheels instead of the annoying inside wheel spin exiting corners that the 350 suffers horribly from (at least mine does).

 

look at post 15 https://www.clublexus.com/forums/sho...d.php?t=365496

here lies the other problem Giggity, the VDIM also detects the front wheel speed to slow the vehicle to maintain control. If it slows the speed of the rear wheels to match the front wheels . Which now defeats the purpose of a limited slip unless you have the VDIM turned off .

The VDIM would have to be less obtrusive like the the IS-F or the M3 to take full advantage of this LSD. I think the IS-F might cut in before the M3. Dont quote me on that!

 

Well crap!- I guess swapping the diff from a 250 won't work since the 350 has a differnt housing all together...

Guess I'm back to saving up for the Tom's diff.
Thanks for sticking the proverbeal fork in my easy LSD solution slee18!

 

The Tom's LSD being a 1 way LSD, would i be able to drift with it? Is it harder? would both wheels spin at the same time?
Thanks