Who has better LSD
 

Who has a better LSD for its money for a 1991 G50

Guard Transmission.....

Guard Transmission |

Timothy Leary.

My first thought lol.

Owsley Stanley

http://www.nytimes.com/2011/03/15/us/15stanley.html

Guard all the way, have one in my 964.

I love my Quaife.....can't make a comparison to any other though, just the Quaife eliminates wheel spin under any circumstance without even noticing....

Dennis

I stagger corrected.

man 0 man!!!! I got all dressed up for this??

well since I come this far, #3 is probably right... hate that about scott,,,, he always presumes he's right..... and most times he is... hate that about him...

Matt at Guard has the only diffs and rebuild parts we will use for a Porsche. Just finished building one for a GT3RS yesterday.

Cheers

From what I've read, the quaife is good for lower speed / tighter stuff like autocross. It's also maintenance free. But it doesn't work if a rear wheel is unloaded so if you have a lot of rear swaybar or like to use curbs in the track its not for you.

The clutch type ones are better and more consistent for track work, and better for big power cars. But they induce low speed understeer and the clutch plates eventually wear.

Take it with a grain of salt, as while I've driven both types, neither has been in a 911. As with anything, best is to identify your needs and luck the best solution for you.

It's sucks, doesn't it??

How might the Guard LSD be better then the O.S.Gicken?

I wish i remembered how i know that..........................

http://forums.pelicanparts.com/5570567-post12.html

Rennlist Discussion Forums - View Single Post - Got to get a Giken - The ONLY LSD to have.

Timothy Leary's dead na na na na no he's outside looking in just. couldn't resist. Funny the stuff that sticks in you head.

I have run the Kaaz 1.5 way in my rally cars and more then likley will run on in my SC...

The asymmetric lock up feature of the GT and late Porsche lsds is really nice in that it has a higher lock on decel to help w/ braking and can then be set up to be less intrusive in different cornering situations where various amounts of throttle are used but still put the power down on full throttle out of a corner

The last ting you want is a diff that's intrusive at the wrong time, which is why most cars come w/o any limited slip diff at all

Guard- Don't bother with anything else. If you do not get a Guard up front, you will after the first one you bought.

This....

Spot on.

I've used the Giken ones as well as Guard and the latter ones are much preferred.

You really do get what you pay for.

As always we appreciate the support of our customers. I generally recuse myself from these sorts of debates, but if anyone has specific questions about the design, function or materials of my products I am happy to contribute.

And just an FYI but I am currently back ordered on G50 LSDs about 60 days. Not even Singer can cut the line and get one earlier (we are their OEM as we were for RUF for a number of years). We doubled our sales of G50 LSDs last year and just could never have predicted such an insane spike in business. First world problems.

The other thing I will mention is that Rum Bum just won back to back Grand Am titles using our LSD in 2012&2013. BGB also won the GX Grand Am title with our LSD after we started the season by sweeping the podium at Daytona. We've won the GT class at Daytona multiple times.

Lastly, we did back to back tests at Daytona. Two identical cars. Same driver (Guy Cosmo) on the same day on same tires. Nearly 2 seconds a lap faster with the GT LSD versus the Giken.

Regards,

Matt Monson
Guard Transmission llc

Ps. We also make TBDs if that is the design you prefer. Plavan ran one for years.

Blotter Barn | LSD Blotter Art Archive



And now back to our regularly scheduled program....

Think I might just get the Guard 60 days back order not that bad.

Yeeks
 

Hi. Hope this is not the case for 915s. Exotech (mark) should be contacting you for two LSDs to come east!!!

Not a problem. I've got plenty of 915 LSDs, all 3 versions (most people don't know that there's that many different differentials throughout the model lifespan, Giken sure didn't when they first came to market 2 years ago).

The G50 thing was weird. I can only attribute it to two things:
1. The 964, being the last "cheap" air cooled car to build into a racecar became very popular in the last 12 months.
2. A lot of GT3 Cup owners started to get worried that their bearing flanges were going to break off the cast factory housing and instead of rebuilding with new clutches just bought new billet units.

http://forums.pelicanparts.com/uploa...1378189568.jpg
This is actually a picture of another aftermarket manufacturer's LSD, but it illustrates the failure that the GT3 Cups are susceptible to if left in the car too long. In 2012, TRG had 2 DNFs at the 24 Hours of Daytona because they left factory LSDs in the car for too long and the flange broke as pictured.

Perfect!!!

Matt,
I have a stock '74 915 with 7:31 R&P. Which LSD do I need and what kind of lock-up is recommended for DE track use? Can it swapped in the car?
Please PM me with price. Thanks!

I first put an LSD (a Quaife) in my SC because I thought I might be getting rear wheel spin coming out of one corner on one track. On long reflection I suspect I wasn't really getting spin, as the 3.0 in stock trim isn't all that powerful. Certainly you can't just break the rear end loose. Nice thing about the Quaife is that it is fine for the street and autox, because you really don't notice it in action.

Then I came to believe, from reading stuff on the Internet, like here, that the real value of an LSD for fairly low power to weight cars was in braking - if the bias is set up mostly for decell, you don't have the rear end moving around as much as the rear tires bounce around under heavy braking (those zones on tracks tend to develop ripples, like gravel roads washboard, due to all that horizontal loading). So I switched to a more conventional LSD from the Quaife.

I am such a bad test driver that I can't say I have noticed any difference there either.

Jager - it is physically possible to swap in an LSD with the transmission still in the car. But I think if you try to do that you will regret it.

Have you ever set up a ring and pinion? The chance that the mounting plane for the ring gear on your current differential is exactly in the same place relative to the pinion side to side as that on the replacement, and that the replacement's dimensions from the mounting flange to the places where the output bearings sit,are identical to what you have, is pretty small.

That means adjusting the preload (how stiff it is to turn the diff, in inch ounces or something, which you adjust by coming up with the right total shim stack thickness), and especially adjusting the side to side location, or if you will, the depth of the mesh (which you adjust after preload by moving shims from side to side in various combinations of thickness) can be time consuming. It requires frequent installation of the diff, then removal, changing the shim stack split, reinstalling, reattaching the measuring devices, checking, and doing it all over again. Very much an iterative process, and a whale of a lot easier with the transmission bolted to your engine stand.

Some are able to do most of this with bluing rather than dial indicators and so on, but it is still very much iterative. I suppose if you rebuild transmissions all the time you can reduce the number of iterations quiet a lot, but there seems to be no linear relationship between what you measure and the distance you move the gear side to side with the shims, so hitting it just right on the second try isn't something you can count on.

On top of that, getting the bearings off is tricky, as they are a press fit and it is hard to pull them off without using, and thus bending, the bearing cage. So that is time consuming in itself unless you have made up a set of setting bearings (honed their ID so they slip on).

A benefit of removing the transmission is that you can take it to a shop to have this done.

Matt's picture of a broken LSD is illustrative of one more reason a guy has to think hard before deciding he wants a Cup Car. Those of us with lesser mounts sure would like to keep up with those guys, but the maintenance costs for them are really terrific. You might be able to race a lifetime with a 915 and never break anything. Sure, lots of other stuff will eventually wear and need replacing, and the case may need some work to keep the two shafts in line. But you aren't looking at 100 hour or less gears or differentials.

Walt,
Thanks for the input. My plan is to take the tranny or car to Gary Fairbanks in CT and have him do it. My buddy dropped his off, went to lunch and 2 hrs later, it was done for $200!
BTW, I agree with your points above. I can hold my own with GT3s in the turns but they pull away on long straights, then I catch then again on the next turn, with a 40 yr old 911 with mostly stock 3.2L.

I have one of Matt's ready for my 015 rebuild. I almost hate to install on the gearbox it is one beautiful piece!

I agree. KAAZ is the way to go with moderate engine power and torque below 300. 12 clutch plate models for 911, 964, 993, 986.

Made In Japan - $1525 form KAAZ USA on line store. Talk to Ray.