turbo den

Yes it works.
Tight corner exit much improved. No more flashing traction control light.

I am have IS300, Scion FRS, and IS250. They share the same pumpkin. final drive from FRS is 4.1

Gville350

iTrader: (10)

I bet with that LSD AND the 4.1 FD the IS250 feels like a different car, huh?

Jeff Lange

iTrader: (1)

If only the FR-S was out when I did my swap.

I'd like to get the 4.1, but I'm pretty happy with the 3.9.

Jeff

redspencer

iTrader: (1)

It's great to see more IS250 clublexus owners taking advantage of the compatible IS300 or FR-S/BRZ differentials for their LSD performance upgrade. With the IS350, the options are more limited and significantly more expensive.

There's definitely a night and day difference between an open differential and a LSD and it's a shame a LSD isn't offered as an option for the 2IS or 3IS like it was for the IS300. Supposedly, the upcoming RC350 F-Sport will have a torsen LSD available as either an option or standard equipment so if that rumor is true, Lexus is moving in the right direction.

RVCAis250

What are all the benefits exactly from putting in a FRS/BRZ LSD?
Sorry for the "noob" question but I've always wondered what all the talk about LSD's were about

and also, what are the downfalls if any? lower MPG?

Tarrant64

LSD will assist in ensuring that a wheel that has less grip or none at all doesn't receive the bulk of the power. This happens with open diffs and you lose some control and acceleration on spinning tires. LSD will take that power and apply it to the wheels with more grip, and an open diff will often waste power on wheels without grip. Helps a lot in acceleration and cornering.

Gville350

iTrader: (10)

http://en.wikipedia.org/wiki/Limited-slip_differential

Downfalls? Tendency to push the envelope in the corners I guess.

GiantsFan

iTrader: (9)

So ... if I understand this correctly ... this will also help with acceleration correct? (But lowers the top speed at the same time?)

Gville350

iTrader: (10)

Was this question aimed at the LSD or the FD (final drive)?

smokyis350

iTrader: (21)

Is there anyway we can fit a FRS LSD into the IS350? Looking into improving my track time with the IS.

GiantsFan

iTrader: (9)

Final drive.

redspencer

iTrader: (1)

Then 'Yes' to your question. the 4.1 Final Drive will give you shorter gearing with better acceleration at the expense of a lower top speed (and maybe a slight hit on your gas mileage).

scott1256c

I thought the final drive ratio was determined by the differential. At least in a car. No?
So I would have thought using this LSD in an IS350 would move the ratio from 4.083 to 4.1
Is that not correct? If it is correct, isn't that a pretty small change?
Actually, isn't that less change than you would get by changing the rear tires from
255/40/18 to 265/40/18? (which I quickly calculated to be a change of
tires 1.012 vs.
gears 1.0042 , but I may have done that incorrectly)

redspencer

iTrader: (1)

Yes, the final drive ratio is determined by the differential. For the 2IS, the FRS/BRZ differential is only compatible with the IS250. The IS-F LSD is the OEM differential that is compatible with the IS350.

IS250 MT Final Drive = 3.91
IS250 AT Final Drive = 3.73

The 4.1 FD of the FRS differential will make a more noticable acceleration difference in the IS250 AT version.

scott1256c

Thanks.
Some of this is my confusion. I thought
was aimed at the question on whether this would be suitable for the is350, but that was actually 2 questions posed by 2 people about 2 different things.
And here I was hoping I had another option to explore for an LSD.