lobuxracer

iTrader: (2)

That's way easier than the ISF diff. I spent about 4 hours with a die grinder taking little bites and test fitting until I could just squeeze the spool in the housing. I'm fine with using a die grinder, and I've done lots of cylinder head work with them, but I really wanted to only take the smallest amount I needed to clear. The area I had to grind was on the side, the same as FIGS did: http://figsengineering.blogspot.com/...-lock-tcd.html

Overall, I did much the same as Mike did - I installed polyurethane differential bushings front and rear, and it made a HUGE difference in reducing wheel hop.

Gville350

iTrader: (10)

To put it simply, a 2-way aggressively locks up the internals of the LSD upon deceleration AND acceleration...great for drifting. The 1.5-way locks up tight upon acceleration, but only partially upon decel...which is MUCH more street-friendly.

lobuxracer

iTrader: (2)

FWIW the OS Giken is NOT a 2 way unless you order it from OS Giken as a 2 way. The TCD I have is a 1.5 as are all of the "off the shelf" units.

NotSoJibby

I hate to be "that guy" but would pulling the whole pumpkin from the FRS/BRZ work in an is350 as well? I think i read somewhere that the subframe is different but im unsure. Id rather not spend half of what i bought the car for on a diff.

Jeff Lange

iTrader: (1)

No, it won't fit an IS350 subframe, propeller shaft or side axles. Sorry. :\

Jeff

NotSoJibby

Thats crummy haha Thank you for the info though!

edhohoho

I've read that it works best for snow and track driving, but does upgrading to an LSD confer any benefits in daily driving? Not likely to track anytime soon, but I drive a lot on the freeway and like to take turns hard and need to weave in and out of traffic. I really enjoy the improvements in handling that all my upgrades have made so far (sways, springs/struts, front/rear suspension braces, front LCA bushing, ISF steering ECU--the rear chassis brace is next) so I'm wondering if this will be a worthwhile (and expensive labor-wise) last upgrade I make before I can stop and just really enjoy the car. Thanks.

Gville350

iTrader: (10)

Besides max summer performance tires, the LSD would be the next step in my book. You've got everything else it appears.

edhohoho

Does having an LSD affect gas mileage? I see someone selling an OSGiken for the IS350 and there was a comment implying lower gas mileage. If there is an effect, is it a large decrease in gas mileage? Does it have to do with that unit being a 2 way differential (it looks like a special unit from Japan if I recall correctly)?

Even if I find a late 2005 IS300 Torsen differential, would it be better to go with a newer FRS/BRS differential due to potential for wear and tear?

I'm nearing the completion of what I think I want to do with my car, the LSD is still on my mind.

lobuxracer

iTrader: (2)

No impact negative or positive on fuel economy unless you drive like a hooligan after installing it.

Differential life is typically 500k miles if it is maintained at all. I wouldn't worry about a used one at all unless it has been abused - driving like a hooligan all the time, making the wheels hop, etc.

WylieKylie

iTrader: (2)

The gas mileage comment in that for sale thread is because the seller was running an IS350 diff/ring/pinion in an ISF, because of the difference in gearing that big 5 liter V8 was always turning more RPM, thus lowering the mileage.