Rear-axle steering on 991 GT3.2

[pumper1]

Has anyone had problems with excessive play in the rear steering motor, which results in a side to side movement of the rear wheel, and what was the outcome / solution to this problem. My OPC is due to check the problem and I am assuming it will be covered by the warrantee. Any comments ?

[Cheib]

Not me. How many miles have you done?

[pumper1]

7,000 2or3K on the track

[Cheib]

pumper1 said:

7,000 2or3K on the track

Well you’ve used it properly, certainly more than I have used mine or 99% of other owners. Maybe there is a problem with the RWS but we’ll only find out as more people put that kind of mileage on.

Edited by Cheib on Saturday 23 February 08:34

[Porsche911R]

What’s the schedule for new hubs and centre locks on a car tracked that much ?
3k is one hell of a lot of track miles.

[pumper1]

The actual mileage on track is 2025 being 15 trackdays since October2017 It was when I was having a new geo setup that the problem was highlighted.

[Slippydiff]

Not uncommon :

https://www.pistonheads.com/gassing/topic.asp?h=0&...

[GT4RS]

I don’t have a .2 gt3 but run a 991.2 4s with rear wheel steer have now done about 10k and not suffered any problems with the RWS. If anything the car gets better with more milage.

Tyre wear has been excellent too.

[Porsche911R]

GT4RS said:

I don’t have a .2 gt3 but run a 991.2 4s with rear wheel steer have now done about 10k and not suffered any problems with the RWS. If anything the car gets better with more milage.

Tyre wear has been excellent too.

I guess it more to do with 2k track miles pulling 1.7g on the bends.

Hence why I asked about the hub replacement, as a tracked needs hubs quite often.

[Macca993]

My 991.1 GT3 track service manual said the locking mechanism in the hub assembley and associated hardware needed replacing at 6000 track miles.

No one is pulling 1.7G at the track (unless they are using slicks or hitting ractional transients).

I ran 5000 track miles in 18 months with no issues and there are many on Rennlist with 4-5x this mileahe without issue. However like many systems on the newer cars these can be prone to failure and wear outside of the norm/expected. i suspect the OP had just got unlucky in this instance or else a possible off track excursion could have somehow contributed to accelerate the situation so that the actuator is out of spec...

[isaldiri]

Macca993 said:

No one is pulling 1.7G at the track (unless they are using slicks or hitting ractional transients).
.

People see maximum g spikes that the car app records and like to claim they are doing that kind of thing on track or on the road.....

[Macca993]

isaldiri said:

People see maximum g spikes that the car app records and like to claim they are doing that kind of thing on track or on the road.....

LOL, yes it seems common. Those transients are often a milisecond caused by a bump, chicane etc. Ive been using AIM telemetry (CAN bus) with my GT3/4s the last 3-4 years and regularlu calibrate the system. A fresh set of Michelin PSC2 will typically generate approx 1.45G sustained maximum. That number falls to the mid/low 40s by the thrid day and when they are done high 30s to low 40s. They tend to heat cycle out before they wear out as such in my experience.

Sustained G as you know will be what creates the most wear on the centre lock hub assemblies and other related suspension components. I guess this is why they dont want us usinging slicks which will generate mid 50s to mid 60s Gs regularly.

[Porsche911R]

isaldiri said:

Macca993 said:

No one is pulling 1.7G at the track (unless they are using slicks or hitting ractional transients).
.

People see maximum g spikes that the car app records and like to claim they are doing that kind of thing on track or on the road.....

As normal you missed the point, the G reading was a moot figure plucked from the air.

You will , on track be a constant 0.5 G load higher in the bends on hot cup 2,s over a road shod p zero GTS 911. Hence the higher wear and hence why you even have to swap hubs on new 911 GT cars due to the much higher loads on these cars now.

[isaldiri]

Porsche911R said:

, the G reading was a moot figure plucked from the air.
.

As are most other things you say!

[Slippydiff]

None of which is particularly helpful to the OP either ...