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I'm skeptical about your hypothesis but maybe not as sensitive as you are.

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I installed a Giken variable locking limited slip on my '06 Cayman S. I loved it for track days, but had to avoid full throttle sometimes to avoid push of the fronts. The rears just hooked up. Used to be, the inside wheel would spin and I'd have to wait until after the apex to get on it. I don't autocross, but I never felt like there was less power with the Giken...just more push. Because it was variable, I could regulate the amount of push with the accelerator.

I liked the open rear-end better on the street...making fast corners etc. But Giken improved the track-day experience. I was surprised that there was a trade-off like this.

I'm not familiar with wave-track. Just letting you know it ain't 100% better with limited slip.

:)
 

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After talking to Wavetrac, there is no issue with the LSD. The perception of lack of power is the seem less transmission of that power to the outside wheel, so more throttle is available without wheel spin. No break in period is required. Just an adjustment in throttle response by the driver with both rear tires pulling hard but the sensory input is very different. The engine noise can rise above the normal subconscious levels and the grip level is higher without the PCM going off. That is why I referenced the potential need for a Sprint Booster on race mode exiting the apex for the straightaways. In reality, Sprint Booster would not work as I need the total flexibility of the throttle modulation in other areas of the course for smooth deliver of power, without the jerky on and off that may occur with higher throttle sensitivity and higher throttle reaction.
The car seemed very balanced; no understeer or oversteer on turn in and no snap oversteer with throttle on at the apex. I was just surprised how much throttle I could apply without losing the rear. No other adverse effects occured, except for my sensory input being off. In retrospect, the Wavetrac LSD is very seamless, even on a damp course, through the slalom features and two 180 degree corners.
The whole suspension can stand more stiffness, so one hole closer to the stiffest setting on the Tarett GT swaybars, both front and rear and a little higher settings on the Ohlin golden control knob adjusting the compression/rebound. That should reduce the weight transfer across the car and also from acceleration and braking keeping the Hoosiers planted to the track surface.
 
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You will certainly get more power to the ground with an LSD, and spare your rear brakes in the process. An open differential limits the torque to the outside wheel based on the amount of torque that the inside wheel can withstand, plus "internal" friction (inside the differential). In the analog era, one could drive slowly around a turn under full power while the inside wheel spun furiously. PSM or torque vectoring applies the brakes to the inside wheel i.e. applies "external" friction (and/or pulls throttle as necessary) to prevent wheel spin, and this brake torque is transferred to the outside wheel. A LSD uses internal friction to the same effect, and prevents (or greatly reduces) PSM from applying brakes and/or pulling throttle. A gear style torque sensing/torque biasing differential is seamless for street and Auto-X use. Its weakness, and the primary reason for its lack of acceptance on race cars, is that it can burn up when one drive wheel comes completely off the ground. The Wavetrac addresses this weakness.

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I have signed up for an Advanced Driver Skills Workshop. This course will give me some additional sensory inputs; auditory, directional, balance points and G forces with the Wavetrac. I can get additional seat time and hopefully enjoy their wet skid pad.
 
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I have signed up for an Advanced Driver Skills Workshop. This course will give me some additional sensory inputs; auditory, directional, balance points and G forces with the Wavetrac. I can get additional seat time and hopefully enjoy their wet skid pad.
Great! I eagerly await your report.

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Looking to fine tune the Wavetrac LSD power delivery together with stiffer suspension settings (stiffer Tarett GT Swaybars and stiffer Ohlin compression and rebound) and Hoosier A7 race tires as my seat time increases with this mod. The Wavetrac operates with a gear drive and simple sliders that apply power to the unpowered side (wheel off the ground) seamlessly. No need to turn off the PCM except for the standing start. Mooty's quote was before the development of the Wavetrac, which takes the same spot as the Torsen, Quaife, Giken and other ATB's, but is more effective powering the lifted spinning wheel.

Mooty said; Post #11 of this thread,

"dont just put an LSD on your car.
figure out why you need it.
if you drive on street, even if you drive recklessly, you DONT need LSD. it either make you understeer too much or its presence is not felt, money wasted.

if you AX, you most likely need torsen.

if you track, DE, or race, you need plate type. torsen wont work if you lift wheel off ground and that's what happens if you are in the tight turn on track.

if you are spinning inside rear tire (when the tire is on the ground) you need stickier rubber. cayman s at 295hp shouldn't be spinning rear inside tire if it's on dry pavement with good rubber (notice, i said ON the pavement) if you are lifting tires, you need plate type.

grossly simplified, yes, but this is the gist of it."

Another owner's experience!
I've now got 18 days on track with the Wavetrac and I'm very happy with it. The car is VERY stable under hard braking and it's fantastic coming out of corners. I've had several experienced drivers either drive my car or ride along this summer and all have commented on the excellent handling. I also have JIC Cross Competition coilovers, neg 2.1 camber front, neg 2.3 rear, stock LCAs, BFG R1s and Pagid Black front/Orange rear.

And from Wavetrac the benefits include-
Handling is greatly improved with a Wavetrac differential as more torque can be transferred to the ground under fast cornering. This ensures a faster and tighter turn, and a huge improvement in vehicle stability. Traction from a standing start is improved as more torque can be transferred to the ground without the risk of one wheel spinning. This has huge traction benefits to powerful rear wheel drive vehicles such BMWs or Mercedes.

So, the Wavetrac takeaway is-
  • Throttle on out of corners much better than open diff
  • Very stable under hard braking than open diff
  • More stable through slalom features than open diff
  • Improves standing start traction
  • If you are lifting inside tires, Wavetrac transfers torque from the unweighted tires to the outside drive wheel
 

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With the Wavetrac- the internal slider powers the traction wheel when the inside wheel is in the air/off the ground. That's the distinction between Wavetrac and other ATB LSD's. What this means is a smoother delivery of power after apex with throttle modulation.
 

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Recently, last week I was forced to use my daily drive wheels/tires (1yr old Michelin PS4's) as my older RE71R's had a tire flat. So, I had the install shop that I used from my purchase of the RE71R's from TireRack to repair the bolt that was stuck in the face of these 2 year old race tires. I am trying to get these to the wear bar for replacement. My daily drivers are in the same diamention as the RE71R's, and Hoosier's A7's; 255/35/18 f and 275/35/18 r.

What I found is the LSD actually has more work to do when using non sticky tires (Michelin PS4's), that would normally be used every day. Like going around tight corners, or turning rt at a stop sign, hitting the gas, even starting on slopped intersections. All sorts of activities where with sticky race tires, the M97 engine does not have enough torque to light up the inside tire, but would with the daily drivers tire. I found that even slalom type roads the LSD adds more control of tire slippage allowing more power to be used. With wet roads, this LSD is even more pronounced by the way it delivers the workload to the tires. It seems to take just enough power from the inside tire to remain traction and give that power to the outside without causing a snap oversteer event. It's effect is pretty amazing.

While I justified my cost of the ATB LSD through my racing activities, the greatest actual benefit is to daily activities. When racing recovers, most likely this summer, I am sure that will be my focus. I just wanted to show the excellent utility of the LSD with a higher daily ratio of the cars usage. I never would have thought the Wavetrac would increase the street drivability of the Cayman 987.1 as it seemed very tossable to me with the open diff.
 

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This post was supposed to showcase the ATB LSD Wavetrac on a wet autocross course. Well, I had read the wrong weather report and it just got worse. I had my Hoosier A7's mounted and shocks adjusted for a dry surface. Then had a couple of beers and watched Homeland. Checked the weather, got nervous, went to bed, got up around 3:00 checked the weather again, upgraded from light rain to thunderstorms starting a 7:00am, then called it a day. No way was I going to drive 40 miles in the rain with slicks on my car. Changed back to my daily OEM wheels/tires Michelin PS4's to haul my bike around. I will report on the next event in a couple of weeks.

For some unknown reason, my whole class has upgraded their cars this past winter, too many GT3 and GT4 these days, who are shooting for top time of the event. However, we have Ron Bauer, a 5 time National Solo Champion, who drives a modified Miata to the top time at most events. Only the longer ones, will the GT4 catch him.
 

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1st autocross competition today. The Wavetrac certainly provided additional drive from the outside tire in both of the slow 180 degree corners of the track. I did not notice any downside of additional understeer or understeer in the slalom section, seemed neutral. The car seemed settled with the Ohlin's setting of 4 clicks front and 5 clicks r. I am building confidence in how the rear end stays planted, even when the throttle was to the floor coming out of these slow turns.
 
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How does a thread go on since 2006 ?
Never gets old I guess or there's always something new
Wonder what the record is for longest running thread ?
 

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I'm merely reporting current info using some of the best tools/mods available to the Porsche brand in autocross. 06-08 Cayman's did not come from the factory with an LSD, later ones did, but rarely do they show up on any sales data sheets, so not many were ordered. I have a hard time trying to find out if some competitors are using a LSD in the stock classes, unless they click on compression (Guard). However, with newer technology, PVT, it's a moot point, but it will cost you to get this technology as its only available in a newer car.

What I am finding is that this LSD, takes the years old Cayman to another level, without the drawbacks of a clutch type. In other words, elevating a 13 year old car to match current levels of performance but not costing $100k or much more in my PCA class (GT3- 3.3 or to 4.0 lt, modified). For top time, i'm in the middle of the GT3's, GT4's, newer 911's, BMW M2's BMW M3 and Corvette's. Its going to interesting when the C8's start showing up. I see they have a LSD in one of their packages. You probably want to add this to your spec list as it certainly adds performance to a mid engined car.
 

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I had an lsd added to my 04 BS in 2013 by that shop in CO when they re-manufactured my trans but I don’t remember which unit it was
 

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Sabbretooth- Exactly, if someone had a PTV car and a friend with the same ca without PTV but a Wavetrac LSD, this would be very interesting to see the pros and cons of the two systems. Wavetrac works very well with Porsche current PSM either on or off in various models. I have one installed on my 987.1 Cayman S. Really helped me last weekend providing additional thrust starting just before the apex and through the exit of most turns.
 

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There doesn’t seem to be one manufactured for non PTV PDK cars. Do you know where one can be located?


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Call Wavetrac, their phone number is 1.949.362.8700.
 
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