Pierce Motorsports KAAZ LSD, anyone have one?

[Mattypeeperz]

I am going to install an LSD once the autocross season is over and I saw that Pierce Motorsports offers an LSD. Has anyone tried that yet? I know about the Quaife and Wavetrac, but I have Pierce braces and am happy with their quality.

 

[KKaWing]

Be ready to change out your trans fluid every other oil change as the diff shares fluid with the trans. Such is the reality of plate LSD's. They perform "better" but they are also not install and forget.

Edit: Take a look here http://www.kaazusa.com/80w90.html

 

[M-Sport fan]

^^^Yes, and it's not just the greater heat that the clutch plate type diffs generate (and therefore shear down the gear oil quicker), it is also the many 'fines' from the discs which they throw off into the transaxle fluid/gear oil which can cause wear to EVERYTHING in the whole transaxle, if not changed out frequently.

I had an Eaton Posi in the rear axle of my Z28, and the carbon clutch pack discs in that thing would turn the gear oil pitch black in <1000 miles (and there were only about a quarter of the total disc plates in that thing than in the KAAZ diff).

 

[Mattypeeperz]

Extra fluid changes doesn't bother me, I was curious if anyone has gotten it yet. Since its not my daily driver, I wanted the best option for autox and occasional track days

 

[kevinatfms]

Extra fluid changes doesn't bother me, I was curious if anyone has gotten it yet. Since its not my daily driver, I wanted the best option for autox and occasional track days

Best option is a helical gear type differential with the correct bias ratio for the type of driving you plan on doing. The KAAZ diff doesnt look like a clutch plate type diff but more of a cone type according to the description on the website. Either way, when the cone wears....you suffer. It could also be a cam engaged type of diff but i havent seen anything that says that.

The worm gear/helical style does not wear like the clutch type and provides a better bias ratio during engagement. Get a helical diff like the Mfactory or Quaife for road racing or auto-x.

 

[M-Sport fan]

^^^Or the Wavetrac.

BTW; we do not have the option to choose the bias ratio within a given company's product (at least as far as I've seen ), only whatever bias ratio differences exist between the 3 or 4 different Torsen/worm gear type MANUFACTURERS' set/given, on the shelf, products for our platform.

I don't know which ones allow the end user to set bias ratio by spring pre-load, IF any.

 

[kevinatfms]

^^^Or the Wavetrac.

BTW; we do not have the option to choose the bias ratio within a given company's product (at least as far as I've seen ), only whatever bias ratio differences exist between the 3 or 4 different Torsen/worm gear type MANUFACTURERS' set/given, on the shelf, products for our platform.

I don't know which ones allow the end user to set bias ratio by spring pre-load, IF any.

The bias ratio is set by the gear pack that is installed. I have never heard of the spring replacement for changing bias ratio? The only worm gear type diff that i know of with a clutch type lockup(to prevent an "open" while one wheel is airborne) is the T-2R. What spring preload are you talking about?

 

[M-Sport fan]

The bias ratio is set by the gear pack that is installed. I have never heard of the spring replacement for changing bias ratio? The only worm gear type diff that i know of with a clutch type lockup(to prevent an "open" while one wheel is airborne) is the T-2R. What spring preload are you talking about?

Yes, that is the ONLY one I know of (the T-2R), and the pre-load is the major difference in bias ratio between it, and their more pedestrian/factory installed as stock, T-2 diffs (~2:1 bias for the T-2, ~4:1 for the T-2R, at least as they were used in 4th gen, 10 bolt rear axle f bodies).

I agree with you on the above, and was only asking if YOU knew of a way to change the 'on the shelf' bias ratio of any of the available Torsen/worm gear type diffs for our cars (when you sort of implied that by saying "the correct bias ratio", as if they can be changed) , since I thought it was impossible to change that from how they come from the various manufacturers.

 

[kevinatfms]

Yes, that is the ONLY one I know of (the T-2R), and the pre-load is the major difference in bias ratio between it, and their more pedestrian/factory installed as stock, T-2 diffs (~2:1 bias for the T-2, ~4:1 for the T-2R, at least as they were used in 4th gen, 10 bolt rear axle f bodies).

I agree with you on the above, and was only asking if YOU knew of a way to change the 'on the shelf' bias ratio of any of the available Torsen/worm gear type diffs for our cars (when you sort of implied that by saying "the correct bias ratio", as if they can be changed) , since I thought it was impossible to change that from how they come from the various manufacturers.

Torsen used to sell the gear packs to change the ratio. This was mainly on the 8.8 Ford rear end. That is the only way that i know of. And from what i remember they were a true nightmare to change.

 

[M-Sport fan]

Torsen used to sell the gear packs to change the ratio. This was mainly on the 8.8 Ford rear end. That is the only way that i know of. And from what i remember they were a true nightmare to change.

The actual, on the shelf T-2Rs for the GM 10 bolt solid rear axle cars fell out of favor with (and were eventually discontinued by Torsen/JTEKT after a couple year run) due to the cases of the latter production runs cracking with any hard road course/autocross use on sticky tires.

 

[kevinatfms]

The actual, on the shelf T-2Rs for the GM 10 bolt solid rear axle cars fell out of favor with (and were eventually discontinued by Torsen/JTEKT after a couple year run) due to the cases of the latter production runs cracking with any hard road course/autocross use on sticky tires.

Wasnt only GM. Ford had quite a few in the FR500S race cars along with a few they sold through the FRPP catalog. They revised the part number and removed the "clutch" design and from what i remember it came back out as just a T2 and T2R with differing bias ratios. No more clutches.

Either way, I think you cant go wrong with the Mfactory or Quaife helical diff for the Fiesta. Both have great warranties and look to be stout units.

 

[M-Sport fan]

Either way, I think you cant go wrong with the Mfactory or Quaife helical diff for the Fiesta. Both have great warranties and look to be stout units.

ABSOLUTELY, and I believe that we can add Wavetrac to that list as well, although I would like to see how the one Pete (on here) installed into his new high powered setup fares during hard road course use.

 

[kevinatfms]

ABSOLUTELY, and I believe that we can add Wavetrac to that list as well, although I would like to see how the one Pete (on here) installed into his new high powered setup fairs during hard road course use.

Pretty sure Wavetrac uses a carbon clutch on the worm gears for applied pressure. See the website listed below under "Here’s something else you won’t find in any other design:"....

http://www.wavetrac.net/technical.htm

So even though they are carbon fiber, the plates themselves can adjust the bias ratio. This is unlike others as it introduces a wear item into the mix. How long it wears would be a question to the manufacturer. Since they warrant it from defects for lifetime i assume that when it does wear down they require you to purchase a new friction disk.

So while the "wave" gear locks the axle under zero load conditions, it really is the carbon bias plate that locks each wheel to absorb that immediate stopping force. Other gear type differentials usually tell you to load the axle by applying brake pressure when one wheel is unloaded therefore acting as the "disk". Instead of replacing clutch/bias plates in the diff, you are replacing brake pads. Quaife and others rely on the bias spring along with driver input(the brakes) during zero load operation to keep the diff biasing torque across the axle.

If what i am thinking is different than what they are explaining please let me know.