Hi, rear wheel steering is included in the 2017
911
Sport Package. I have some questions about it.
Does rear wheel steering only activate at very low, parking lot speeds, and at very high speeds? What about taking curves at middle of the road speeds, such as 45 mpn?
Does rear wheel steering add a significant amount of weight and complexity?
Do you feel rear wheel steering is worthwhile and adds to the agility and handling of the
911
?
Rear wheel steering is the most salient part of the Sport Package to me, and if it is not that worthwhile, I think I would skip that package altogether.
You might want to ask the dealer rep to confirm for that model. From what I've read below 31 mph the steer is opposite up to 2.8 deg. Then above 50mph the steer is the same as front wheels up to 1.5deg. Presumably from 31 to 50 the rear wheels just have the static toe alignment setting. For the 991
GT3
static toe is .13 to .20 deg (toe in). The system does add weight but not a lot. Can't recall. As for complexity it is something else to go wrong, but from experience so far have not heard of any failures or issues including GT3s driven on track. On the
GT3
it's essentially transparent. Maybe a pro could tell it's working but I can't sense anything obvious. As an option I'm not sure I'd pay for it. For street driving these cars are already so capable and the limits so high, I wonder what difference it would make to most drivers. When the 991
GT3
was introduced it was claimed that just the RWS cut significant time on the 'Ring lap time. So maybe some justification for a track car, but then there's the risk of something else to fail.
RWS will buy you a few seconds on a 12.9 mile circuit on the nurburghring. That's about it.
Are you tracking your car and need those milliseconds to add up?
Doesn't seem worth it to me. I will bet 99.9% of 991.2S
Carrera
owners can't tell the difference.
If you're going to race your car you should get it, if you're just going to drive spiritedly you might enjoy it a bit more, better low speed turn in. It can't be retrofitted so if it's reasonably affordable and you keep your cars I say buy it and PDCC.
IIRC the rear wheel steering will go counter to the front wheel steering at low speed, do nothing at medium speeds and go parallel to the front wheels (to keep the car nose pointing forward) at high speed.
I have this fear that it might stop working and I would never know.
I am sorry man but you seem a very nervous/wary sort. Ancticipating problems wih a manual transmission (reverse versus first) in a
Boxster/Cayman
, worried about it being damaged, worried that rear wheel steering in a
911
will fail.... Of course all legitimate concerns. More stuff you add, more stuff to break and fix at premium prices at a
Porsche
dealer. Which is why, I hate adding these options on a street car. If you want value for your money without the car giving you sleepless nights, I recommend buying a CPO
Porsche
(
Boxster/Cayman
/
911
), lightly optioned and enjoy it. Repairs will definitely dent your wallet. Parts will fail. It is a premium German car. Be prepared for $ 400 oil changes and 5k clutch and brake jobs. You can find an indy shop and save a little but these cars are not cheap to run and maintain. A set of new
tires
, every 15-20k miles, will set you back 1500 bucks minimum. I just replaced the original
Pirellis
on my car with
Michelins
and it cost over 1500 bucks with
tires
bought at TR and installed by a local shop. Think of a
Porsche
as taking care of Samara Morgan. You think you want it, you get it and one day you will want to strangle it and drop it into a deep well.
Last 2 posts made me chuckle. On whether the RWS is working it would be easy to see the counter steer at low speed in a parking lot.
Porsche
has a video of it. Up to 2.8 deg is easy to detect. Harder to see at 50mph + though. I think it's likely if there is a failure the cars computers will pick it up and give a warning. Agree these cars are not cheap to run.
Edit- checked the owners manual and there are 2 possible warning messages for RWS: "Rear-wh steering fault Adapted driving permitted" and "Rear-wh steering failure Careful continuation possible"
I had the same 4-wheel steering (Super Hicas) on my 1993 300ZX TT…the speed transitions and angles could be different. The original stated benefits by Nissan and
Porsche
, over 20 years later, are the same. I kept that highly modified car for 12 years and never had a problem with it. I have it on my 991 TT and it is still transparent. I have to assume that
Porsche
would have the system to be as good or better on its current cars.
I have a 1991 Nissan Z32TT and have had no problem with rear wheel steering on my car for the last 17 years. It is reliable and really not noticeable while driving
The current issue of the PCA's Panorama magazine has a 2 page article on rear axle steering. Not super in depth, but pretty good as an introduction. Most of the
points
seem to have been made up in previous posts, but here are the highlights:
At low speeds (less than 31 MPH) it will adjust the rear axle by up to 2.8 degrees in the opposite direction of the front wheels. At high speeds (greater than 50 MPH) the rear axle can turn up to 1.5 degrees in the same direction as the front wheels. It's supposed to increase maneuverability at low speeds and increase stability at high speeds. The article says rear axle steering is responsible for shaving 15 seconds off the 7:25 time at Nordschliefe's in a
GT3
.
I'm guessing I don't have the skills to really notice the performance benefits at high speed, but that's something you'd have to answer for yourself. I think I'd have to try it at low speeds and see if I can notice it.
