LSD question - Quaife (or other LSD) vs. the Wevo 915 Spool...

[dd74]

I know little to nothing about LSDs, but while trolling through the Wevo site, I saw this:



In lieu of other LSDs, the 915 spool offers 100% rear wheel lock, and if anything, is the sharpest piece of machinery I've seen in a long time.

What do the tranny/LSD experts think of something like this when compared to a LSD for a street/track car?

Thanks.

[air-cool-me]

parking lots wouldent be too much fun...

this is a track-only item if im not mistaken...

[dd74]

Originally posted by air-cool-me

this is a track-only item if im not mistaken...

Well..yes. But when has that stopped many of us?

[Steve@Rennsport]

Oh man,........having driven 3.0 RSR's & 935's with a spool, its virtually impossible to turn unless the wheels are spinning. Nick C. is very wise in his assessment.

Racing ONLY, IMHO.

[KobaltBlau]

what you want is a multiplate clutch type LSD.

I would choose Guard Transmission if my trans didn't already have a recently rebuilt (and very effective) factory unit.

is Guard's asymmetric 915 unit out yet?

[air-cool-me]

man i wish i had the cash for a LSD

i really hate it when the inside rear goes up in smoke....
rdane's 80%er would be nice! he was running away from me outa tight corrners!

so... diff guys... cant you just weld the ____ gears to acomplish the same thing as the spool? whats the advantage>? weight?

[Steve@Rennsport]

Nick:

You certainly can weld the spider gears that will have the same affect as a spool.

Weight is the difference as the cast differential cases are somewhat fragile. I've broken my fair share over the years on my race cars.

[air-cool-me]

\

Weight is the difference as the cast differential cases are somewhat fragile. I've broken my fair share over the years on my race cars.

ive noticed.... my new 3.3L turbo is killing my 915 5th gear now whines as bad as the PP -OT board. im going to check to make sure the fluid is full and i don't have any metallic surprises..

Im having a hard time visualizing the forces involved.. would something like a spool or high lockup LSD shorten the life of the "cast differential cases "?

ive only read about bearing retainer and syncros dieing... what are the more common 915 death blows?

thanks alot steve!

-nick

[Bill Verburg]

is Guard's asymmetric 915 unit out yet?

I believe that geary replied in the affimative to that ?

I just bought one of his 40/60 units for my 993. Since the 911 won't be tracked anymore i'll leave the 40% ZF unit that is in there. It seeems to be about right for street use. Active enough to know it's there but not overpowering in tight or slippery spots

[rdane]

Being a big fan of a l/s I quizzed Hayden about the spool. Figuring like DD "why let that stop you". One of the deciding factors for me was Hayden telling me how i might not make it through an intersection with a spool with out going all the way across the other lane over the curb.


All that sounds a lot like what one of the other smart guys here said:

Originally posted by Steve@Rennsport
Oh man,........having driven 3.0 RSR's & 935's with a spool, its virtually impossible to turn unless the wheels are spinning. Racing ONLY, IMHO.

[Steve@Rennsport]

Originally posted by air-cool-me
\

ive noticed.... my new 3.3L turbo is killing my 915 5th gear now whines as bad as the PP -OT board. im going to check to make sure the fluid is full and i don't have any metallic surprises..

Im having a hard time visualizing the forces involved.. would something like a spool or high lockup LSD shorten the life of the "cast differential cases "?

ive only read about bearing retainer and syncros dieing... what are the more common 915 death blows?

thanks alot steve!

-nick

Hi Nick:

Spools REALLY torture differential carrier bearings, CV joints, and put further loads on the already-too-stressed ring & pinion. For competition cars, its a boon in the hands of a really skilled driver but it does add to the maintenance load,...

High lockup LSD's are OK aside from the increase in understeer (diabolical in the wet) but with the proper suspension components and adjustment, that can be minimized to a large degree. Its all about what you use the car for.

915's and Turbo motors are a recipe for disaster since they simply do not hold up. For a 915 to even have a chance, you'd need pressurized lubrication, big coolers, and all the nice WEVO bits to strengthen the bearings. Even then, it will not hold up to a 350 HP, 400 lb-ft Turbo motor. BT, Tried That.

Gears, sliders, anchors, bearings are all undersized for those kinds of loads and exacerbated by large tires.

[air-cool-me]

pressurized lubrication, big coolers, and all the nice WEVO bits to strengthen the bearings

thanks for the answer...


alright then.. i will just budget a new 915 every couple of years

[Steve@Rennsport]

Originally posted by air-cool-me
thanks for the answer...


alright then.. i will just budget a new 915 every couple of years

LOL,..In the long run, you'd spend less money if you use a G-50,....

[air-cool-me]

G-50,.... what a conversion run on those?

3/4 the price of my car?

believe me i would have one if i could afford one!

[Steve@Rennsport]

Originally posted by air-cool-me
G-50,.... what a conversion run on those?

3/4 the price of my car?

believe me i would have one if i could afford one!

Too many variables to say on that,........trans aquisition costs, rebuild, conversion, bits, etc. You'd sell your 915 and get some cost recovery, tho.

Given the current (and rising) costs of 915 parts and the frequency of repair, you'll spend that and more,....

Save your $$$$ and do this right. Look for a good '87-'89, G-50 w/LSD and the hydraulic clutch setup from a crashed car. In the end, you and your wallet will be happier and you'll spend less time fixin' and more time drivin'.