[grygst]

Hi All,

I've got a 981-series Cayman GTS that I use almost exclusively for the track. I'm considering installing a Wavetrac limited slip, and I've two specific questions for those of you who've already gone down this path:

(i) Does Porsche's e-diff interfere with the Wavetrac's operation, such that it provokes any strange or unhelpful behavior? And
(ii) Do you like the behavior of the Wavetrac under deceleration?

On the first question, I run with ESC turned off, but the e-diff seems undefeatable, so I'm concerned that it might cause strange or undesirable behavior -- such as cutting power or applying braking when the Wavetrac is transfering torque from the inside wheel to the outside.

On the latter, I'm looking for more stability when I'm hard on the brakes with steering input applied, but I don't want so much stability that I get front-end push instead.

More generally, have you been happy with your choice of LSD?

Appreciate any and all input.
Thanks!

 

[bigmoguls]

I can't say how the Wavetrac will help with stability, but starting to trail-brake before making steering input changes would likely yield good results. Under Hard braking, the rear tires have very little traction.

 

[[email protected]]

@Apex1 has this diff in his car and might have some insight. My experience with torsen style diffs is they they pretty benign. We run clutch style diffs in all of our race cars and tailor the ramps for the driving. With a 2 way you definitely can tell it's there on decel, the 1.5 way is less intrusive and better for wet conditions.

 

[Apex1]

The Wavetrac acts more like a 1.5 clutch type LSD during braking. I can give an example, down hill twisty backcountry road, with some braking, compression braking and acceleration, the Wavetrac keeps the rear end in line, even with hard braking and turn in. Doesn't make sense that it would help here, but it does because it allows more throttle and brake modulation. In autocross in the wet (no standing water) with Hoosier slicks, the car just came alive. Even in an overdrive situation of being too hot (late) for the corner, using max trail braking and turn in all the same time without the rear end coming around I saved that corner. This was almost the same feeling I had in the downhill example of keeping the rear from swapping. I also feel the same feeling with throttle on coming out of the apex. It's traction application has a gentler effect, thus not causing a snap oversteer scenario.

I started with the PSM on for a couple of events using the standard slip angle of 8 degrees before the PSM is activated then progressed to leaving it off giving a bit more slip angle and even better results. A yaw switch can be fitted to completely turn off the PSM interference. But, keep in mind that the 987.1 braking system is not as complicated at your GTS. By checking your rear caliper temps, before and after install, you may notice less heat being generated by the nannies to keep the rear end in line. The clutch type that Joshua refers to creates almost a lock up situation, while the Wavetrac slider allows more deviation between wheels/tires in the unweighted rear threshold braking scenario. For me. the Wavetrac works very well putting the power down from the apex and does not cause a snap oversteer situation, thus allows more throttle modulation. It seems to be controllable and in threshold or trail braking, the Wavetrac adds stability without a total lock up of the two axles. I am using my car for 85% daily driver though, not a trailer tracked car. It's a great add to my particular use. No clutches to replace or clicks on deceleration.

 

[grygst]

Thanks, guys, for your input. Josh, I'll send you an email, and we can take the discussion offline. - Christopher.