sechsgang

So first off, I've never loved a water-cooled non GT variant as much as I LOVE the base/S 992's. Ive got a C4s with now 2500 miles on it and dare I say, it's nearly a perfect daily driver sports car, checking off nearly every box with the highest marks I can give a car...but I've had one issue with mine that I'm really curious if anyone else has experienced with their 992s...and curious about those with both 2 and 4wd.

The issue? My particular car seems to get pretty unstable in the wet when cruising on highways, and especially when changing lanes on the highway, and particularly susceptible to hydroplaning... Im not talking about drastic steering inputes here either...I'm talking about a normal slow lane change. The first time I had the car in the wet and did this a little more aggressively, I ended up with needed to actually correct with a real amount of countersteer, which quite honestly beyond shocked me...I've had and driven (hard) almost every variant of 911 1987 and on, and not one has ever felt like that, with the closest feeling being my former 996 GT3 with nearly chorded semi slicks during a downpour coming home from a track event running 3 ish degrees of negative camber. After that, I tried a few lower speed lane changes (in sport, normal and wet mode), and they all felt surprisingly unnerving. My first thought was maybe I really am driving too quickly for the conditions (even though I've literally never had to think about this in any of my previous cars which I've driven the exact same way)...and then when I slow down to where the car feels comfortable (maybe 55/60, every other car seems to fly by and with complete ease). The first times I tried this all, I had the car on winter tires, then swapped them to the summer, had the alignment checked and since have spent plenty of time adjusting tire pressures etc etc...nothing seems to make the difference. I'm scheduled to take the car into service for this, and the guys at my department know my history with cars/racing etc etc and were pretty shocked when I mentioned that to them. FWIW, my car IS a RWS car, and 4wd...Im curious to take a 2s out, or a car without RWS and see if that makes a difference, but figured out I'd see if anyone else has experienced anything remotely like this. Oh, in the dry, the car is phenomenal, and I've done everything I can to test out the handling characteristics I can think of. I can't help but think its some TC or RWS algorithm causing a hickup here, but really don't know.

Any thoughts????

crimewave

I have a C2S, on the few rainy days we've had here in LA, I can confirm my car does feel 'unstable' to the point where I feel like driving it is a bit dangerous in the rain. In my M4 I never had this problem. On one particular day, I was driving up to LA on probably the worst day for rain in SoCal and the amount of times I was hydroplaning all over the place (it's really loud and scary in a 911 compared to my M4) so I just went 40mph all the way to LA. Also, just pointing out that I don't have RWS. I've also wondered that it could be an issue with traction control, I had an alignment checked and my tire pressure to comfort settings yet my car still seems to 'float' around under semi-hard acceleration.

ipse dixit

What kind of tiress?

WellDressedCar

Tires are everything.

crimewave

I have the Goodyears, my M4 had michelin PS4S

Jim Wilke

Big fat tires and lots of power and it seems that Porsche uses less traction control than other companies.

Metalblond

When I first got my 991.2 4S with RAS my car did the same thing (in high wind as well). Changing tires made some of the difference but it still wasn't my ideal bad weather driver. I was hoping the 992 didn't do the same thing.......

rileyracing1

Urggg .... Goodyear tires suck ......All of them ...Wouldn't use them unless they were given to me and then I would just use them for burnouts ...

I have Pilot 4s on my C4s and I have gone up to 150k in the rain without issue ..... Wind can be an issue though depending on direction ..

Dan Nagy

Light weight and wide tires probably equate to hydroplaning. On my 991.2, I found that changing tires to Michelin’s helped. Having a MT made me feel I was more in control on wet roads, but when it’s raining, I am in the right lane.

sechsgang

The winter tires were Pirelli scorpions, and the summers are Pirelli Pzeros...BOTH of which Ive had on numerous other 911s, and lighter weight ones with wider tires with 2wd (I've driven a bunch of GT3s in the rain, even with sport cups/sport cup 2s) and non of them have had this flighty unstable feeling in quite the same way...My last C4s (991.2 with RWS, 500 AWHP tuned and lowered ) never had any problem remotely close to this, it was a pretty epic high speed rain car, which is why this catches me as such a surprise! After reading some of the above responses, its "good" to know others have felt this but somewhat concerns me as well, as the whole point of these cars is that they are utterly usable, all year, all day long...I really think Porsche has over programmed something and underestimated some real world driving variables. If I was one of their engineers, Id be trying some different suspension and TC tuning solutions...but I know Im not going to spend thousands trying to trouble shoot that. Will be interesting to see what Porsche says...

Richard_Wallace

Haven't experience this in my 992 C4S yet, but have had limited driving time in the rain - having it only 1 month.

I have had this problem though on one other car - it was an AWD BMW. It was scary, and felt like the car was going to lose control in the rain. Also when this car would go from a rainy roadway, then under an overpass (where it was more dry), it would feel specifically amplified then - that the car was going to go sideways when going from wet to dry and back to wet. In that secenario you would actually feel the car kind of torque a bit. But you would feel the same instability - just less pronounced - on a regular wet roadway, all the time.

After much analysis - and trips to the dealer, as this was not normal - in any way. Turns out there was an issue with the AWD/traction control and when it initiated. (They first tried new tires, different make, then alignment, etc. etc.)

It was so bad (before they finally figured it out) - that I would not drive it if it was going to rain. Almost felt like when you mis-match tires (make/tread) on the front and back. It was so squirrelly that you felt like it was going to go sideways, but only in rain. My guess it is not the tires - but the AWD or traction control system.

sechsgang

This is EXACTLY what I'm talking about. I've described it like mismatched tires a couple times to a few people I know...and why I switched from my winter tires to my summer tires the car came on just to make sure that N spec tires OEM were on before really thinking about talking the issue.

Metalblond

Were they able to fix your AWD/ traction control so it stopped doing it? My 911.2 was like this exactly, I've survived horrible New England weather in Corvettes and Miatas--so I know how to drive sports cars in the rain and snow- but was shocked when my Porsche behaved that way. Now I'm dreading my new one will be squirrelly too.

dhirm5

Tire pressure can play a role here, also -- in other threads seems Porsche is frequently delivering these cars with absurdly high pressures.

sechsgang

While that's definitely true, it's not the issue here unfortunately! Unless the wet pressure is supposed to be in the low 20s vs my current 32-36 ranges...but I find that extremely unlikely.