Question: Im currently on my way through Germany and when hitting 135 mph there is a loud whining electronic noise (probably indicating that I have hit max speed). When I back off it subsides. There is no mention of this in the Owners Handbook. Anyone has a clue?. My Disco it is limited to 188 km/h when it simply cuts off the throttle but with the RRS there is more to go it is just the noise that puts you off.

I would imagine that it's been electronically limited to 135 MPH.

Only way to find out its true top speed would be to remove the limiter, but doing that would probably void your warranty. 2014 L405 SDV8 RR Autobiography

2012 RRS SDV6 HSE -Orkney Grey with A/B bodykit - Now Gone
2007 RRS TDV6 HSE - Zermatt Silver - Gone

Assuming you have the new RRS 5 litre SC engine, its top speed is specified in the book as 155mph which is 250kph.

There will be a hard limit applied here but if it's anything like the Evoque (same or similar control thinking) there is also a soft speed limiter you can set yourself and it may be this which is going off.

I can't see they would limit the car to "only" 135 mph when the competition does rather better. (ML55 AMG, Cayenne turbo etc).

By the way, I would love to know what the instantaneous fuel consumption is when you are driving at that speed. Single figures would be my guess. Mark

SVR in Estoril Blue

Yes there is a variable speed limiter as Mark says.

It is cruise control or speed limiter, if I read correctly.

Agree it should do 155.

I will have to speak to the dealer about this. There is a very penetrable highly pitched (loud) noise when you go above 135 mph which abates gradually when you slow down below 135 mph. After having tested it a couple of times I don't think it has anything to do with speed limiter our other electronic issues, rather something to do with the airflow around the car.

Quite difficult for you or them to reproduce the problem on the A3... are you sure it's not one of your passengers getting nervous...

More seriously, I suggest you get a passenger to try to capture the noise on an iPhone to show the dealer. If it is to do with airflow, try closing the dash vents, tilt the mirrors in, make sure the glass roof is fully closed, all trying to see what might make a difference.

I'll be interested to hear how stable the car is at speed, how planted it feels and how sensitive it is to cross-winds. I've had a few OMG moments in my 911 when appearing from behind an artic into a cross wind (though at greater speed)... Mark

SVR in Estoril Blue

I agree with the procedure but as I was alone on my way back yesterday I did not want to fiddle with my I-Phone at that sort of speed. I think you can only reproduce it at Millbrook on the Oval so will see how LR proposes to check this.
I'm accustomed with driving (fast) on the German Autobahn as i lived in Germany for 10 years and had various sports cars (Porsche Turbo, Aston V12V). With the normal Range Rover and the Discovery you actually don't feel comfortable going at higher speed than say 200 km/h for the Range and 188 km/h for the Discovery as they sway quite a lot in curves and are prone to suffer from cross winds. Not so the RRS which is very stable and induces quite a level of comfort to push on. Brakes are fine with good grip.

That's good to hear that the RRS inspires confidence at speed, not bad for what is quite a tall vehicle with a large cross-sectional area.

Your problem will certainly cause some head scratching at the dealership... Mark

SVR in Estoril Blue

Possible causes, wind noise from window wipers, a panel gap on the front of the car, or wind sweeping under the car causing something to vibrate at such speeds. Ive experienced all these issues before on other vehicles but not the RRS. What size wheels are you running?

I agree. The dealership will not have a clue unfortunately.

Regarding the stability at high speed I think that it is here where the Active Dynamics play a big role. In high speed corners the springs load up and you don't get this floaty feeling that you have in a Range Rover.

Occasionally you can get very high pitched whine from timing belts or air-con, alternator / other ribbed belts that are only heard in the cabin at very hi-speed is there any indication when you rev the engine while stationary - gently build the revs.

Some tyres will also do it when part worn.

Can you tell if the noise is high up or low in the front etc.

At the sort of speed you're talking about small aerodynamic defects can set up noises - usually a whistle rather than a whine so you should also check your...

- bonnet seal at the leading edge;
- headlight surround seals;
- the lower air dam and the other diffusers have all their fixings in place;

Yes, I'm wondering whether the supercharger drive belt (I assume it is belt, not chain, driven) is slipping on the pulleys at this high engine speed and loading? Mark

SVR in Estoril Blue

Yes, I'm wondering whether the supercharger drive belt (I assume it is belt, not chain, driven) is slipping on the pulleys at this high engine speed and loading?

However, we're going to be none the wiser without a noise to listen to, so the audio memos app on an iPhone is good. Set it going at low speed (one button tap), put the phone down, accelerate away. Mark

SVR in Estoril Blue

I took it to Guy Salmon this afternoon. They were clueless and further told me that there was no way that they could test this at warp speeds. I will now call a dealer in Germany and see whether they have had same problem.

It is a loud whine (not a hiss) so unlikely to be aircon/ventilation caused. Supercharger belt could be a good clue. Initially I mistook it for being a sort of built in high speed alarm but there is no such thing.

I can confirm it does 155mph

And its pretty quiet when doing it, the only surprise was it changing up around 140MPH 2016 RRS 4.4 TDV8 Autobiography Dynamic in Montalcino Red and Stealth Kit