Wanted to share this good comparison between the Quaife (Gear) LSD and Carbonetic (Clutch) LSD. Here is some information I gathered from each manufacture.



CARBONETIC is a clutch type LSD which means it locks up 100% both of the axle shaft. If both axles do not lock up 100%. The car can not deliver power to the tires evenly. Which means loosing power and you can not use all your power at tires as intended.

Porsche actually has a factory LSD that is a clutch type with very low initialization. So if you went to a gear type LSD, there is no advantage for performance. The only advantage to a gear type LSD is no maintanence or failure due to never locking up 100%.

Quaife for example is a gear type that works very smooth due to the gears which do not stop. There is almost no sound emitted.

Carbonetic's clutch type has metal disks and high initial torque which makes alot of noise and engaging is very harsh. For delivering power, this is better where the Quaife is nicer for street or track use. Usually people say the Carbonetic is working ON or OFF. This is the only negative for clutch type LSD systems. If you set up the LSD with low initial like the OEM LSD, it will work smooth but the performance is very weak.

The maintenance of the Quaife gear LSD is simple as it almost never breaks. Clutch type LSD's require oil maintanence and usually metal type LSD's require the oil to be changed every 3-5K miles even on street driven after the break-in period. The CARBON LSD version requires maintenance more often after initial break-in period. Generally required to change the oil every 2000 miles due to the carbon disks getting dirty faster. So to keep the best performance, you always need to change oil often.

The Quaife gear system rarily break so you do not need to rebuild them. The Carbonetic metal disk LSD needs to be rebuilt every 8-10K miles. Once you lose initial torque, the disk won't hold well. When they begin to slip, the disks ware out really fast and eventually it will become like a open diff.

The Quaife cannot be set up to different ratio's like the Carbonetic. A Quaife has just one setting. Clutch type LSD's can be set up as the customers like, depend on how strong, fast, timing etc. Metal LSD's are very picky to set up precisely and require a special skill for the set up as you like.

CARBON LSD does not need to set up precisely, the LSD has wide control with acceleration, working very linear. so no make too pick just bolt on and working as you like for most of customer. only have some racer might prefer to have metal one and set up precisely.

For customers who are looking for performance on the street to track, the CARBON LSD is best choice unless you are not interested in dealing with the maintenance.

Here are the Quaife Diffs available for Porsche - http://www.vividracing.com/catalog/a...orsche&x=0&y=0

These are all the Carbonetic Diffs for the Porsche - http://www.vividracing.com/catalog/a...orsche&x=0&y=0

 

Very good info,thanks Dan.

 

i always thought our cars 996tt came with a LSD
i was under the impression you couldnt drift a car with an open diff.

does the LSD make big difference on the track? does one change the front and rear?

 

I have to question some of that info as the Carbonetic LSD I had in my car had carbon friction plates = enormous life length.

I know some of the webpage content from at least one of these manufacturers can be hard to understand due to lack of english language skills/translation. Is there a separation in that text which shows what comes form Carbonetic and what comes from Quaife?

Re the Carbonetic LSD I had in my RWD 996TT, the most notorious features was that engagement of the LSD clutchpack was 100% seamless. It could simply not be noticed, and I could carry speeds into and out of turns which were fantastic. I'm used to racing Cup cars and RSRs so the way my 2WD TT was setup with the Carbonetic, and the non-detectable engagement of the diff was nothing short of fantastic.

I have also spend 2 seasons with a 350Z Twin Turbo (drift/grip) and this also has a Carbonetic with seamless engagement = you can't feel it.

I've driven LSDs with solely metal discs, KAAZ, Nismo and some more I can't remember, and with those there were severe "clanks" at engagement which upset the chassis.

I felt it prudent to comment as a few sections of the information in the first post simply doesn't match (or actually contradicts) my real life testing from running Carbonetic LSDs in 2 out of 2 track cars I've driven during 2009 and 2010.

PS. GMG has run a Carbonetic LSD in their GT2 for quite a while, maybe those guys can chime in as well how they like it.

 

Congrats for getting back into another 996tt Mr. White! Will you be making this another track beast with 2wd LSD again? If so which one will you go for?

 

Just a big warning to fitting a plated diff in the rear. They can make the car very difficult to drive in the wet or snow. The differential as its name suggests allow the wheels to turn at different speeds. on a Right hand corner for instance the inner wheel will turn slower than the outer , as the outer has to travel further. If the diff locks up taking a slow tight corner the rear will tend to hop around the corner which will make the car very difficult and possibly dangerous in bad weather. Even if the diff is not a 100% locker, theris still static friction of the plates to overcome before the dynamic friction takes effect. This can make the dif a little unpredictable at lower speeds.
A viscus type lSD will allow the wheels to turn at different speeds but still do the job of delivering power to both wheels. Plate type LSD's are more suited to motor sport. This is not just me talking out my ar$e. On this issue I have loads of experience of using them in motorsport and making the mistake of having one fitted to my road car. Not a good idea. A very exciting and interesting drive but still not a good idea in a road car. IMO.
Frank

 

Haha thanks for that! Eyed a lot of other cars but how could I go for anything else. There is no substitute. Target always is (for me) to have it as a good track toy, with daily capabilities. I don't have quite the same budget to move with this time around though so it'll be a slower process.

For LSD I will do Carbonetic again, it far surpassed any requirements I had or experiences I have had with other diffs, plus supposedly it lasts a lot longer between services than a Cup car LSD.

 

I just ordered a Wavetrac LSD for my 996TT, similar design to the quaiffe but if one wheel loses traction completely it wont allow that wheel to receive all the power. Plus they are a really good price and aside from longer axle stub bolts are a direct replacement. Once I get it I'll do a thread on the install as I'll be doing it myself.

 

Congrats Mr. White! I see you've taken some measures to prevent another incident!

Anyone know what type of diff the E46 M3s use? Whatver that is, it's incredibly smooth and works super well!

 

MrWhite, you have way more track experience than I so not trying to put that in doubt, but I'm wondering, if you can't feel the Carbonetics LSD working, how can you be sure it is locking up 100% as advertised? If it does as you say, sounds like the best of all possible worlds. What kind of longevity can be expected from this diff ?

 

One can feel it working, but one can't feel the actual step of engagement (usually a solid clank with a yank in many LSD diffs). The engagement/force build up is seamless, so it build up gradually with no "jerk". One way to tell that is works though is there is no inside tire slip for traction where it would be with no diff. I ran with different settings too on how aggressive it would look, and was able to feel the difference between the settings, mainly because I ususally ran a sporty street tire rather than R-comp.

Carbon friction plates supposedly last about 10 times longer than metal plates. If you set the diff more open/less friction (fewer plates) it will wear a little faster though since fewer discs share the "slip" inside the clutch pack. In terms of miles or time, unfortunately I couldn't say. I've run 1 car (350Z) för 2 seasons so far with no sign of weakening/needing a change of plates (dedicated track drift/grip car).

Cheers

 

How many plates would you recommend for a 90% track/10%street car?

 

I'll go with appr 2/3 of the 100% clutch-plate combination.

 

The M3 uses a plate diff but with a clever actuation using a shear pump that reacts to the different wheel speeds across the axle. It allows for 100% lockup without the negative effects that Sunnyside refers to.

Google "BMW M-differential shear" and look at the results for a fuller explanation.

And I agree, they work brilliantly. Had two E46's in the past and an E36 evo. Very flattering cars to go sideways in!

 

I've been seriously considering an OS GIKEN.