If you didn't spec the PTV you have an open differential. Can you ever feel only one rear tire spin? In all my experience with open diffs I've hated the feeling of spinning one wheel. With a LSD I feel both wheels spin and can rotate the back of the car controlably. However, I wonder if the 718 is unique because I see a lot of cars without PTV and a local Porsche tuner couldn't find an aftermarket LSD for the car. Consider that the $25k 200hp BRZ/86 twins come with an LSD but many 718s don't and no one sees a need to add it later. Of course, this question is aimed at drivers who feel comfortable power sliding their car. Saying "it just grips" means "it has too much tire", "it doesn't have enough power", or "I don't feel comfortable breaking the rear end free".
Owners w/Open Diff
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Just wait for the summer, when the asphalt is hot, and go hard at it from a stop on a 90 degree corner. It slides the inner wheel, no questions asked. Yesterday it did it twice. Summer is coming in Houston!... Michelin PS4S N0, if you want to know...
However, that being said, two seconds after you floor it you are in illegal speed territory, doing it with a power slide may be more class, but oh the joy in the eyes of the LEO cutting a whole bunch of tickets!...
However, that being said, two seconds after you floor it you are in illegal speed territory, doing it with a power slide may be more class, but oh the joy in the eyes of the LEO cutting a whole bunch of tickets!...
@ Lelanddjt. I know limited slip differentials help exit out of slow corners. The Lotus Elise guys claim their cars corner better without the LSD. Of course, my new (used) Elise has LSD. Maybe someone with deep understanding of 981/718 handling with/without LSD can weigh in.
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The PSM/stability and traction control wont let your wheels spin and its only under certain situations that the PTV/LSD will make a difference such as fast cornering, accellerations out of tight corning, particularly uphill and low traction situations like in the wet, you just get a lot more accelleration and less traction control intervention.
Without PTV/LSD I don't think you really notice the difference for most purposes, at least not like the old days where as you say you would feel one wheel spinning coming out of a corner. The PSM alone is really quite good and the weight over the rear wheels and great balance also helps, unlike the front engined cars. I'd push the car to its limits as is and if you find it is losing too much traction then see what you can do about it.
I believe Guards used to make an LSD for the 981 so that might fit the 718 but I beleive it might have only been for the manual. Apparently the size of the PDK casing is a little prohibitive for after market LSDs. I would do a search yourself and see what you can find otherwise might be worth trading for a car with PTV/LSD if you really need it. I would also contact Quaife.
That can be fully shut off, right? I've never driver a sports car with traction control.
An idea is to get the PTV option and then install a disable switch so you can turn off the brake activation feature and be left with a mechanical LSD. Anyone heard of a way to disable the smart part of the PTV diff? I'd expect some track guys have done it to preserve their rear brakes.
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We picked up our car at the Porsche Experience Center in Atlanta and did the "free" drivers school.
We used an open-diff, base Cayman with PDK (same as our car).
My wife took most of the sessions (I've been racing SCCA and vintage for years).
But I did try the wet skid pad with the "kick plate". With the nannies turned off, it was very tough to save the car. With nannies on, it was easy. The instructor told me he races a Cayman with the nannies turned on. Less fatiguing.
I think the stability control might eliminate the need for most of the LSD benefits.
You can see a photo from our training session here:
Cayman spinning
We used an open-diff, base Cayman with PDK (same as our car).
My wife took most of the sessions (I've been racing SCCA and vintage for years).
But I did try the wet skid pad with the "kick plate". With the nannies turned off, it was very tough to save the car. With nannies on, it was easy. The instructor told me he races a Cayman with the nannies turned on. Less fatiguing.
I think the stability control might eliminate the need for most of the LSD benefits.
You can see a photo from our training session here:
Cayman spinning
Stability control on the Porsches is VERY good. It will still allow a little bit of yaw before stepping in, and in PSM Sport, even moreso. I took my Cayman on a frozen lake, and with PSM turned completely off, my experience is similar to @aeronca65tl. It was quite difficult to keep it from spinning like a top (and I had winter tires mounted)
For what it's worth, I do have PTV as well.
Edit to add: I'll also mention I have quite a bit of experience driving on the ice, so it wasn't simply inexperience causing me to spin the car.
For what it's worth, I do have PTV as well.
Edit to add: I'll also mention I have quite a bit of experience driving on the ice, so it wasn't simply inexperience causing me to spin the car.
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PSM allows for some interior wheel spin. I can attest to this!
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Agreed. PSM is not a performance enhancer IMO. Using brakes or cutting fuel is a horrible way to tame oversteer. I’ll take a mechanical lsd all day long. FWIW I had an S2000 awhile back and it had a throttle cable and an lsd, abs, and my feet and hands to control the car. Dang I wish I kept it!!
If I could add one thing to my boxster it would be an lsd.
It's so odd to me that aftermarket LSDs aren't a thing for these cars. It must have to do with so many of them being PDK and that transmission must be particularly hard to package one into and do the install on. I'm totally sold on a 718 Cayman BUT I'm waiting for info on the next gen Subaru BRZ, cuz it's lighter, has a LSD, and is probably great in a drift. How weird that's the car I'm cross shopping.
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I guess that with the engine in the middle, PDK and no separate solid axle/diff like in a Mustang, it might be harder to engineer an LSD.
Funny that the BRZ probably doesn't have the power to use the LSD... Gawd they are slow... Sure they handle well, but you have to really be OK with a car that has very little acceleration.(Ive had 2 of them in my inventory and put some miles on them)
Even the base 718 Cayman feels like a monster compared to the BRZ. The 718 Cayman being a mid engine car, has less of a need for a LSD as there is more weight on the rear wheels. That's not to say a LSD would not be a nice thing to have on a Cayman though...
Reading a similar thread about LSDs and PTV, I thought I'd try to find an aftermarket LSD. All I have been able to find is a company, OS Giken, that makes one for the 981s with manual transmissions only and none for our 982s. Also, re: nannies, I rode in a Cayman S with a professional Porsche drive at an HPDE last year and he physically confirmed what one of my dealership's mechanics told me when I asked about switching PSM off or to Sport mode, and his advice was to not bother with it. Halfway into a 400-foot-wide constant radius turn we started drifting sideways, perpendicular to the inside of the turn. As soon as we were lined up perfectly with the straight following the curve, we shot down that sucker like a drag strip. I looked down, and the PSM was not turned off. The driver confirmed this, saying the car registers the constant aggressive driving when you are driving on a race track and adjusts accordingly. I did read a Porsche Tech Workshop document that states how the PSM is improved in the 982 over the previous variations, and one thing Sport PSM is supposed to do is: "Controllability at the performance limit is greatly improved by damping the vehicle's yawing behaviour ..."
Oh cool... That will be a fun can and have enough power to get out of its own way
~300hp will make the car a hoot compared to the NA versions.
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A turbo BRZ with LSD will be great for performance and good value no doubt. The only issue I've heard is if you set them up for track work or a lot of conering with R compound tires and supsension mods the lack of dry sump can lead to oil starvation and engine failure. Hopefully they will sort this out in the turbo car as it is really the only limitation as far as I can see.
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My car has no PTV, and open diff. I always leave PSM off when tracking, but it does activate the rear brakes and slows the spinning wheel coming out of slow corners to act as an e-diff like most cars on the road.
The new BRZ/86 is not coming out with a turbo version. Not sure where you get these rumours from, but its not happening. I'm an ex-BRZ owner, I know.
Interesting... How do you know the brakes are activating in the rear? I was not aware that the 718 activates the rear brakes to help with inside wheel spin without PTV? Is there an option that enables that?
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