speedracr226

Team Rennlist,

I recently moved from a 991.1 Turbo S to a 992 C2S. Overall I love the 992, but when I’m going around curves at a more spirited level, the rear end feels really unsettled. A lot more unsettled than the Turbo S.

Could be the lack of PDCC. Could be the 4S’ that I had on the Turbo S. Could be AWD vs RWD.

Anyone have any ideas? Most important, anyone have a fix?

Michigan 992

Depends on how hard you are pushing it. I found my C2S at high speed in normal mode to feel loose in high speed bends. Switched into sport mode and it tracked cleanly through 125 mph bends and ~0.9 G. If it is not tracking cleanly something isn’t right.

achilleas101

Curious what you mean by unsettled? Like the tires lose grip a little and it drifts?

speedracr226

No, like I can feel the rear chassis move around and pull at the rear tires.

aggie57

I can relate to that; at first it felt to me like the rear alignment was out but that’s not the case. Now I’m wondering if there’s some soft bushes in the rear end somewhere that allow movement which shows up under moderate load but settles under higher loads. I say this as the rear end feels very settled on the track, in fact its really controllable.

Another possibility of course is the stability control playing games.

Autobacs

Hmm....I'll try mine tomorrow. I have in Sport mode punched it and I was going straight and it felt like the car was spinning out a little. Is that what you are referring to? I was a little concerned that I was going to lose control of the car but then it caught and seemed to dig in.
It wasn't a loos chassis loose feel but rather a slide out loose control feeling.

ipse dixit

Difference between RWD and AWD

911Castle

Tire pressure? Try little higher psi

detansinn

This is a feature

garthg

I'm curious what you mean by "more spirited."
Can you be more specific?

aggie57

In a good way perhaps.

Laszlo_Laz

My thoughts as well. I’ve driven AWD 911s and rear end behavior is very different. RWD only you get the usual 911 behavior (which is natural 911) which may feel unwieldy if you’re coming out of an AWD. You need to be put in more driving care into a RWD 911. Which is the fun.

aggie57

While I can see why that may be considered valid I don't believe that's the case. If what I've felt is the same as @speedracr226 then it's actually something quite unsettling when you first encounter it. Press on past it, or say go into PSM sport, and the car is much more settled. It's a weird thing I've never really got to the bottom of but every now and then it shows up - for example with a short, quick turn where you expect the rear end to load up a bit. But it takes a couple of stabs at doing that instead.

ipse dixit

Have you ever driven a 911 without a LSD (i.e., 996 and earlier)?

I think what you are describing is indicative of more old-school, mechanical 911's.

drcollie

This is easy. Your 991.1 Turbo S has All Wheel Drive, your 992 C2S does not. HUGE - MASSIVE - DIFFERENCE when doing corners at speed. They are really different chassis and will drive like different cars.

90% of people that buy these AWD Porsches think the main reason is traction in snow, but the real reason is not that, its because they corner like demons and Porsche knows that. The front is pulling the car through the corner whereas in RWD only the front is being pushed through. I had a 993 C4S All Wheel Drive I used as a track car and when I put R-Compounds on it and ran it through a loop like VIR's Hog Pen,(T14-T17) it would freak out even the most seasoned track junkies who could not believe the stick and pull through the corners. It's amazing.

There is no real "Fix" to the C2S, the solution would be to go back to an AWD Porsche. PDCC helps (I have it on my C2S) but its no substitute for the AWD. You can change the camber and toe to corner better in a C2S both front and rear, but that comes back to you in accelerated tire wear and twitchiness for straight-line driving that quickly becomes annoying.