[sjfehr]

The Sport Chrono retrofit is a button bar and flipping a variable with the dealer's scantool. Dealers seem to be charging about $1000 but you could do it cheaper if you can find an indie with PIWIS or if you DIY the button bar yourself first.

 

[redlfnt]

Sounds like you're convinced that the 987.1 CS is still a great car without an LSD but I just wanted to add my two cents.

I've never driven a car that had an LSD (or at least didn't realize it did). But I have run against other 987.1 owners who have installed one. I run fully stock with PSM off. I can tell you that there was no difference in performance of the cars from my perspective. The other driver was actually surprised that I didn't have an LSD. The bigger difference was probably in driver skill.

In other words, if you know your car's limits and how to push them, you won't miss the LSD. At least not until you get into full competition. There are other upgrades I plan on before an LSD like seats and harnesses, brakes, and suspension.

The Cayman is a great handling car. You feel everything which helps you be a better driver.

I don't daily drive mine. It's a dedicated track car - without mods. So, I don't know how the lack of an LSD impacts street driving.


Sent from my iPhone using Tapatalk

 

[am1985uk]

I had a 987.2 Cayman S for two years and now have a 981 with X73 suspension and PTV. I have tracked them both and have found little difference in the way they handle. The 981 feels a little more planted and a little smoother, but I think that's mainly due to the X73 and other suspension improvements which Porsche engineered into the newer car. I cannot put my hand on my heart and say that I have noticed the effect of the LSD. Maybe if I did full throttle, full lock starts I might feel the difference, but other than that, no.

Maybe I don't drive fast enough.

 

[TerrySmith]

FYI, LSD is a factory option on 987.2. My 987.2 has that option from the factory. Maybe you can find one with factory LSD but I think they are rare. I have read in one place somewhere that the factory LSD is less robust than the aftermarket Guards unit but I've had no problems with my factory unit through 40K miles and 9-ish track days.

Sometimes (when on a curvy road) I wish my '88 911 had LSD (which was also factory option for that car) and maybe I'll put one in that car someday.

 

[cajundaddy]

This statement is patently false "I am under this impression that an LSD can make or break a sports car. "



sjfehr gets it! :cheers:

A Cayman with Sport Chrono software is a surgical tool in the corners. For a street car, AX/DE car, dual-sport car, LSD is a luxury, not necessity. The Miata, BRZ, and stock Cayman are all pretty brilliant in the corners. None of the Spec Boxster race cars run LSD. For a Cayman Cup car running Grand Am racing with all the electronics stripped out? Get the Guard LSD. :burnout:

 

[TenaciousD]

I raced Spec Miata in the SCCA for several years and while that's a very different car, the principles are the same. I started racing on the cheap and my first racecar didn't have LSD. It didn't come into play at most tracks I raced at. When I got much more competitive and it started to matter, it still only mattered at a few very specific corners at certain tracks (think Sebring hairpin). I invested in an LSD and at those tracks it lowered my lap time by maybe 0.1s for each corner where it mattered. So a couple tenths per lap. In Spec Miata that was enough to make me more competitive, but for anything non-competitive the difference is pretty negligible, and on the street it's completely irrelevant. Just my opinion, of course.

 

[Apex1]

So for about $2000, I can get 1, Cobb stage 2 tune (already have TB and IDP Plume, less restrictive air filter and exhaust) and 2, eLSD from my indy. This should give me a sharper throttle response, better wheel spin control, better trail braking, less restrictive nanny out of tight corners. I was just on the Cobb wed site, but did not see a software product for 987.1 yet. Maybe looking in the wrong spot.

 

[cajundaddy]

So for about $2000, I can get 1, Cobb stage 2 tune (already have TB and IDP Plume, less restrictive air filter and exhaust) and 2, eLSD from my indy. This should give me a sharper throttle response, better wheel spin control, better trail braking, less restrictive nanny out of tight corners. I was just on the Cobb wed site, but did not see a software product for 987.1 yet. Maybe looking in the wrong spot.

It depends on what you want the car to do Apex1. All of those "tuner" items will make the car louder and maybe more fun on the street. I expect they will have little or no effect in terms of improved lap times in competition. If you really want to shave lap times, focus on suspension and tires. Maximize the tire compounds for your competition class, add GT3 A-arms to get more negative camber in the front to maximize your contact patch in the corners, maybe lowering springs to firm things up a bit, and a pro corner balance and alignment to get the setup really sorted for motorsport. For the same $$ these things might shave 5 seconds off a 90 second lap where the "tuner" enhancements might shave 1-2 tenths. Spend your $$ where it will generate the greatest returns.

Of course JMHO

 

[digitalrurouni]

It depends on what you want the car to do Apex1. All of those "tuner" items will make the car louder and maybe more fun on the street. I expect they will have little or no effect in terms of improved lap times in competition. If you really want to shave lap times, focus on suspension and tires. Maximize the tire compounds for your competition class, add GT3 A-arms to get more negative camber in the front to maximize your contact patch in the corners, maybe lowering springs to firm things up a bit, and a pro corner balance and alignment to get the setup really sorted for motorsport. For the same $$ these things might shave 5 seconds off a 90 second lap where the "tuner" enhancements might shave 1-2 tenths. Spend your $$ where it will generate the greatest returns.

Of course JMHO

Could not agree more sir. There are plenty of threads in other Porsche forums where guys with money dumped on headers and tune are reporting that while numbers increase in terms of dyno outputs there is no real world practical difference out on the track! I am not smart enough to understand why though but that seems to be the general consensus. Grippier tires, better brake pads/rotors, suspension tweaks seem to be the way to go.

 

[Apex1]

Thanks cajundaddy, I am waiting on Ohlins for 987.1 laster this spring. I will take your suggestion and apply dollars to suspension, tires, corner balance and coaching. If a need for these other two items, Cobb tuning and eLSD, come up this year, I will discuss it with my PCA autocross and DE coaches.

 

[andy7777]

Could not agree more sir. There are plenty of threads in other Porsche forums where guys with money dumped on headers and tune are reporting that while numbers increase in terms of dyno outputs there is no real world practical difference out on the track! I am not smart enough to understand why though but that seems to be the general consensus. Grippier tires, better brake pads/rotors, suspension tweaks seem to be the way to go.

Because the headers n' tunes just push up the power curve so you get more dyno HP somewhere up high with a loss of torque where you need it. On most portions of a typical track with a typical non-pro driver you're still using your torque curve more than pure HP.

The best way to shave lap times is to improve your driving technique.

 

[EvoRoadster]

If you really, really want a mechanical locking differential then start looking for a Cayman R.

 

[digitalrurouni]

If you really, really want a mechanical locking differential then start looking for a Cayman R.

Or even better a guards LSD.

 

[mm981cs]

My advice is to go to a Porsche drivers training, not DE, but a class intended to show you how to fully utilize the unique abilities of all Porsches. Its a real eye opener, with a wet skid pad, fast slalom with a 180 turn to return to start, Braking exercise, apex exercise (figure 8) and a couple of auto cross exercises, the later one for all volenteer Porsche club instructors as well as participants. The neat thing about this course is the ride along by seasoned Porsche people, Guys and Girls with a lot of time in both autocrossing and Porsche racing. The wet skid pad and braking exercises point out the ability of the Cayman to work with and without the nanny. You can see other Porsches, BMW's and other cars, do these exercises, with and without their nannies. My Cayman S had a hard time drifting in the wet skid pad, with the nanny off. A LSD would make the car push much more, which means bigger front sway bar, bigger front tire patch and other modifications to correct the balance. I run P4 class and do not want to run against GT4 and GT3 if possible with modifications outside of stock.

2nd this - my experience in Atlanta was exceptional! Almost got sick spinning around so much and the instructor was bang on. Best 500 bucks you could spend. I would definitely do this before I modded my car heavily, possibly changing the geometry and/or engineering. It will help you see the difference after any upgrades as well.

 

[Apex1]

A couple of months ago, I had a Wavetrac ATB LSD installed in my Cayman S 987.1. Yes, it does make a difference. it makes a really good handling car even better. I can get on the gas earlier than before without the inside tire breaking free. Not only that, but the power is actually routed to the outside tire as well, but not locked as a Guard LSD would do. What that means is, you still have control of your rear, without the fear of a snap oversteer event. This LSD allows seem less throttle input and depending on your rubber, a lot of it. The same thing on braking. It does not lock up tight, but does allow some rotational difference.

With Wavetrac, a good amount of LSD help out of tight corners, some help with slalom in transition, although the Wavetrac does not cause understeer in this area, and threshold braking, but again, not a total lock up so in trallbraking, works well. The unique feature of Wavetrac is the transition at the apex from trailbrake to throttle modulation is smooth and instant.

The install is costly, about $1500. and the Wavetrac price is $1295. The good thing is once installed, you just drive your car without worries about the clutches, no noisy clutch clicks on engine compression. It's guaranteed for the life of the car. No rebuilds after a few race seasons necessary.

So, with wide wheels and sticky tires, like RE71R's, an open diff Cayman S can perform very well as shown by Ryan Clark's 2017 National Solo Championship in B/S class against 54 seasoned competitors. What this says, is the 987.1 Cayman S fulfills the tossable standard very well. With an ATB LSD, even standard tires equipped car's will benefit with more traction out of tight corners, slalom type roads and trailbraking. If you enjoy canyon driving, autocross or HPDE's then this LSD is for you.

 

[FlyinAg]

Great thread!

 

[ochristofferson]

A couple of months ago, I had a Wavetrac ATB LSD installed in my Cayman S 987.1. Yes, it does make a difference. it makes a really good handling car even better.

I am considering having a Wavetrac installed when my ride goes down for some engine work. A few questions for you:
1) Name of the shop who did the install and your /critique/review of their process (sending, pricing, timing, cost, etc.)
2) Oil used (given the transaxle design and frictional requirements for the Wavetrac function). Did Wavetrac recommend this oil or the installer?
3) Shifting feedback - noise, vibration, etc. any deleterious effects?
Thanks.

 

[Richie Fletcher]

Not a lot to add except the following given that you have a Miata and wish to have a CaymanS: I gained a few shareable insights to the LSD plusses and minuses having autocrossed and/or tracked/ club raced (PCA), etc. 924S, 944t, 968, CaymanS, GT3 Cup Car and Miatas (SCCA) between 1990 to 2019. The LSD will do two things well if it's a good one. It will lessen inside wheel spin in a tight corner and it will also create a bit of "push" coming out of that same corner if the corner is not approached properly. I have a Guard LSD on my 2007 CaymanS and had a Porsche Race mechanic in Phoenix, AZ install and adjust it so that there is not much push at all. It has never spun an inside wheel. As many others have said, the CaymanS does not "need" an LSD for normal street and track use. It does, however, become very appreciated when driving speeds are elevated in downpours of rain where it puddles on a course or track in the corners. I like that it is separate from the braking and engine management techniques used. Hope that helps. Cheers.

 

[Apex1]

ochristofferson-Cantrell Motor Sports in Kirkland, Wa installed the Wavetrac. We used Motul 75W-90 Transaxle oil. Works just fine and is recommended by Wavetrac. This LSD does not have clutches as the above Guard LSD does. So Richie Fletcher may need new clutch discs sooner or later depending on his use. My Wavetrac will not need anything. One area where some Guard clutch setups are better is threshold braking do to lock up. Mine is does not lock up 100%, but does offer deceleration aid that prevents threshold wobble. The good news is that since its not locked up tight, trailbraking, apex throttle modulation, and slalom action does not cause understeer or oversteer. This is important as you can use more throttle earlier after the apex without worrying about snap oversteer, because the wave slider does not lock up totally, but close enough to burnout with both wheels spinning evenly for a straight ahead start.

I do wonder about a slight vibration on deceleration at very low speeds 20 mph or so, which I never felt with the open diff. However, I also changed to Function First Orange transmission mounts at the same time so who knows if its the LSD or the transmission mounts. I also have the F First Orange motor mount, so both are subject to additional NHV.

 

[Apex1]

So, just completed another PCA autocross today in GT3 class with my lowly Cayman S. This class was made for those racers who want to modify their rides with a 3.3 to 4.0 liter motor and no supercharger or turbo. Modified GT4's fit this class and I routinely get a lesson every time Keith Brown's shows up. This class also allows us to run Hoosier A7's, which I have.

After installing the Wavetrac, and finally tuning my car's suspension (Ohlin's, Tarett GT swaybars f&r, Tarett Cup LCA's to add camber and track width, etc). Now, I am finding that with PSM on, even with smooth driving techniques, I am getting a couple of PSM interruptions per run. I turned it off and found that I was faster with it on, staying just below its threshold.

Now that I am adding more throttle at apex, using the Wavetrac and Hoosier A7's, I am finding the back starting to oversteer slightly. I do not have Sports Chrono in my 987.1S. I know I can add this feature, but would it modify the 987.1 version of the PSM to up the slip angle just a little before intervention occurs. That would work for me this year if it works that way. Anyone with a LSD and sports chrono activated describe the difference between SC on or SC off and the activation of PSM while slip angle is above 8 degrees. I believe that 8 degree is where the OEM PSM system kicks in. Just want a few degrees more from the PSM before it activates. With the Wavetrac, the PSM activation is not nearly as invasive as with an open diff. So, it will not kill a run, but if you get more than 1 per run, you most likely have lost .5 seconds. The PSM intervention seems much shorter with the Wavetrac, so I can add power almost as soon as the PSM activates.