SleepRM3

Has anyone tried the new Wavetrac torque-biasing limited slip differential?

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

It seems to be an helical gear type limited slip diff that's an alternative to Quaiffe and TORSEN, and the WaveTrac comes with a limited lifetime warranty?

I'm considering adding the WaveTrac LSD to a MY95 993 coupe (street-only application). I like the lifetime set up without the fuss of rebuilding clutch packs in the Guard or OS Giken type LSDs.

Andy's Autosport sells the WaveTrac for $1295 for the 993 G50 6-speed 911s.

http://www.andysautosport.com/porsch...e45792048.html

mcipseric

I have it and have been very happy with it.

e9stibi

Per Steve Weiner recommendation, I got OS Gyken for about 1500 USD at this time.

SleepRM3

mcipseric--have you noticed a difference with your WaveTrac torque biasing differential installed versus without it? Guard Transmission charges $1795 for their version of a torque biasing differential for our 993 6-speeds.

e9stibi--$1500's a great price for the clutch-type LSD.

mcipseric

Yes, but mostly when pushing the car at AX or track.

race911

Call me Old School, but I'll go with the clutch pack limited slip every time. Even in a 911 I prefer not freewheeling into corners. Other benefit is you don't have to worry about breakage from curb hopping. And unless you're pony trotting, you'll be on the curbs at times.

Ultimately, is the $1.99 difference that big of a deal on a non-$1.99 car?

SleepRM3

True enough. I don't intend to track my 993, but I drive it in wintry conditions, and have experienced unequal traction surfaces between left and right driven wheels. This type of condition is where clutch pack LSDs have the advantage. Whether this is worth the initial cost, and the perpetual cost of rebuilding a clutch pack LSD for these rare occasions, is where I struggle.

race911

I'm not sure where the continuing cost comes from, outside of needing to stay within parameters for a track car. And then, even that's only for a track car where you're prepping to a near-professional level.

Personally, I've had three 911s with factory limited slips, plus a handful of customer cars; usually high mileage when the units came into my hands or care. I've put new friction plates in some. When I ended up with the 140K RSA (the one that was to replace the wrecked race car), I thought about popping the unit out and dealing with it. But surprise, surprise, it broke torque on factory spec so I just left it alone. Worked fine for the for the limited hybrid street/track use the car ended up being used for.

But back to the underlying question on the intended use. If I'm getting wheelspin in a forward direction only, and not concerned with braking performance, then what's effectively a fancy Detroit Locker will do the job.

SleepRM3

Ha ha. Torque-biasing diff then BTW, did you sell your nice grey 964 DE car?

Bill Verburg

For track use you definitely want an asymmetric clutch type lsd, for street or A/X use there is a lot to like about the Quaife type lsd

race911

Got me confused with someone else. My 964 stable was a white '92 C4 track rat from '98-'02, red RSA #1 for club racing from '01-'04, red RSA #2 that never became a club racing replacement after I wrecked RSA #1 from '04-'10. No customers with gray 964s that I was involved with either from the early '90s until I started driving again in '95.

Call me weird, but I don't like freewheeling under braking from the autocross days. Yeah, they were torsion bar cars. And my car, and the other one I had installed an early Quaife in were nearly identical. I'd flirt with top time for cars-with-license-plates-not-on-slicks. Always that bit off with my friend's.

Bill Verburg

[QUOTE=race911;10190211...
Call me weird...[/QUOTE]

OK

Most people who A/X do not like the understeer induced by a clutch type lsd, Most that do big track stuff do like the stabilization induced by the clutch types under braking, the asymmetric's are just better at that than the symmetrics.

There are always the outliers though

The effectiveness of factory clutch type lsds over the years has been very variable going from the fairly effective early versions to the ineffective 964 versions to the highly effective 964/993RS versions. Ones perception of the effectiveness of the various lsds depends on the year and also the condition and the function.

An effective clutch type on a sheet of ice is frightening which is why the factory only added them to most cars as an option

race911

See, here's where the Rubik's cube of setup starts coming into play. I've run cars with absurd F/R torsion bar ratios, no front roll bar, square tire setup, you name it. So understeer, in and of itself, wasn't happening. Oh, and that was all on a short wheelbase car. That I lucked into a 904 limited slip and mainshaft + weird gears meant I was completely over my head, set up wise.

Once I "matured" ~20 years ago with a modified SC, yeah I was taming some on-throttle understeer, but I was happy about how I twisted things so the car rotated. Now. Note I hadn't re-entered track events. No way with that car. Once I did, I had a companion car that was more conventionally set up, and then it got the big flares, 3.5L, etc. and have done maybe a single autocross since.

Bottom line is that I'm SO glad there are just known products and experts we can rely on these days, and not have to spend endless hours with "what ifs".

SleepRM3

You are right. My mistake. The nice grey '91 964 DE car was in Atlanta. So the factory clutch type LSD is the one to go with? WaveTrac's still the cheapest torque-biasing differential (TBD). Guard Transmission's version of a TBD "LSD" is $1795. A Clutch type LSD from OS Giken is $2000. Guard's GT3 Club clutch style LSD is $2895, and costs $1050 to rebuild every 5-to-7 years on nontracked cars (every 2 years on tracked car). WaveTrac claims their diff applies torque at zero or near-zero axle loads.

fondueski

I have a wavetrac on my 987S. Pretty recent install. Only 1 track weekend so far, and at Big Willow, the biggest difference I noticed was more stability under braking. At ACS for California Festival of Speed this coming weekend (http://wp.me/p2lHXB-k9) which should be a bigger test... 3 braking zones and 3 slow speed corners where it should really help.