MK3 Stock Clutch type LSD versus Aftermarket (OS GIKEN)

[blkaplan]

Hi guys,

I am new here and am working on a project for my car. Donnie from Montgomery, Alabama told me to stop by. I don't know his screen name.

I am building a 8" toyota rear axle and I am considering either using a stock clutch type LSD or getting an OS Giken unit. Any advice or information is appreciated. I know the OS Giken route will be more expensive but I am autoxing my car and need really good power delivery.

What do people think of the stock LSD? Any short comings? What kind of cost would I see if i bought new clutch discs from the dealer? Has anyone upgraded to the Giken diff? If so was it worth it?

Thanks!

 

[Poodles]

Depends what you're used to. Personally I like torsens for corners and that's most of what autocross is.

I'd love to run a torsen in my MKIII but the IJ torsen is a bit weak

 

[gofastgeorge]

Quite a jumjp from stock to an OS, which is an excellent top of the field LSD.

Like poodles, I run a helical, but mine is the newer T-2 style that was an option in the first gen IS300 Lexus.
They are hard to find, and bring $700 a pop when you do.
But the JZA70 T-1 LSDs are excellent for all except 10 sec passes at the strip.
Big HP, 5000 rpm clutch drops, with sticky drag tires will break them.

I run a beefed up stock unit for my drag rear end.
I shimmed the spring (they only came with 1) about 5mm, and installed a booster spring inside of it.
A fresh stocker break-away torque is 45 ft/lbs.
Mine is now 90 ft/lbs.
But I would never run it on the street, because they break traction easily in the rain when they are that tight,
because they hold more than a wet tire will, and are an over all pain in the ass.

 

[Poodles]

Yeah, after driving my mom's miata with a torsen I LOVE it. It's a bit weird when it breaks away, but you don't get that understeer fight in corners, it actually HELPS you corner.

 

[3.0 GT]

Quite a jumjp from stock to an OS, which is an excellent top of the field LSD.

Like poodles, I run a helical, but mine is the newer T-2 style that was an option in the first gen IS300 Lexus.
They are hard to find, and bring $700 a pop when you do.
But the JZA70 T-1 LSDs are excellent for all except 10 sec passes at the strip.
Big HP, 5000 rpm clutch drops, with sticky drag tires will break them.

I run a beefed up stock unit for my drag rear end.
I shimmed the spring (they only came with 1) about 5mm, and installed a booster spring inside of it.
A fresh stocker break-away torque is 45 ft/lbs.
Mine is now 90 ft/lbs.
But I would never run it on the street, because they break traction easily in the rain when they are that tight,
because they hold more than a wet tire will, and are an over all pain in the ass.

did u reshim it to factory specs? or did u just shim the center spring to bring up the breakaway torque? i would like my stocker to lockup a little better than it is now.

 

[tekdeus]

Quite a jumjp from stock to an OS, which is an excellent top of the field LSD.
Like poodles, I run a helical, but mine is the newer T-2 style that was an option in the first gen IS300 Lexus.
They are hard to find, and bring $700 a pop when you do.

Got any more info on what it takes to install that T2 torsen? And how much power they hold up to in the IS300 world?

 

[gofastgeorge]

did u reshim it to factory specs? or did u just shim the center spring to bring up the breakaway torque? i would like my stocker to lockup a little better than it is now.

I just shimmed the spring, did nothing with the plates, as they did not show much wear.

 

[gofastgeorge]

Got any more info on what it takes to install that T2 torsen? And how much power they hold up to in the IS300 world?

Just bolted it in, it was an just like installing any other diff.
Put on the ring gear, dropped it in the housing, and shimmed to bring the gear backlash into spec..
Not a problem if you have access to the side shims.
I have a bunch, as I always grab them when I am in a scrap yard, and the first time I needed one I didn't have, I ordered the ones I didn't have from Champion.
You can also take your partially dissassembled diff, and the new LSD with the ring gear bolted on to a dealer.
They only charge $50-75 to set the mesh.
But I figured for $75, I could buy about 10 shims, then I just followed the TSRM (to the letter)

There is one on eBay now, but it is not listed for an IS300, it's just listed as a Supra fitment.

I have not heard of any of the IS300 turbo cars hurting them.
And I know a few people here besides me have them.

 

[blkaplan]

I ran a high preload truetrac in my car and didn't care for it because my cars rear suspension can unload the inside wheel. then i had inside wheel spin and power delivery issues.

How good are the stock LSD for autox?

PS, the car is built for autox but gets track and street use as well.

 

[gofastgeorge]

Personal thoughts here.........
The stock LSD is better than no LSD for auto-x, the helical would be much better,

And.......

Sounds like you have way too soft of springs on a 3400 lb car for auto-x, and getting too much weight transfer & body roll.

 

[blkaplan]

Either way I will have an LSD, its just a question of is it 1000 dollars better for competition use.


The car weighs 2730lbs and has a solid rear axle which under acceleration tries to lift the rear right wheel. I also had some geometry and bushing compliance issues that I have been working through to increase the suspensions articulation. The car is very stiff, its not soft sprung body roll causing the wheel to lift, its the car coming up on two wheels.

I have autoxed on torsen style diffs for the last 3 years and I really dont care for them.

Just a heads up on the chassis for the toyota axle swap.

 

[darkspeed]

domo ftw!

 

[blkaplan]

Yo donnie!

 

[blkaplan]

I bought a stock supra diff to start, how tight should I shim it?

 

[suprahero]

I was going to post that Donnie is Darkspeed on here, but he beat me to it.

Mr. Gofast, do you have a rebuilt by you 3.91 that you'd like to sell me for some dragracing?

 

[gofastgeorge]

I bought a stock supra diff to start, how tight should I shim it?

I forget off hand.
I measured the space that the spring fit into, and compressed the spring to near coil bind.
The difference of the 2 measurements is what I cut the spacer length to.

 

[gofastgeorge]

I was going to post that Donnie is Darkspeed on here, but he beat me to it.

Mr. Gofast, do you have a rebuilt by you 3.91 that you'd like to sell me for some dragracing?

Sorry, but no........
I sold my last set of 3.9 gears after falling in love with the 4.56 set I run on the street, and the 5.29 set I have for the strip.
(you may have guessed, I spin my engine just a tad)