plasticam

Hi,
I’ve had my car a couple of months and recently been doing some motorway driving. There is a distinct sensation that the rear end is floating around whilst at higher speeds in a straight line.
Is this normal as I feel like I don’t have full control of the car (it’s actually quite unnerving) and I have to slow right down or cling to the steering wheel.
Low speeds on country roads I might add are great but it’s knocking my confidence in the car.

GratedWasabi

What kind of speeds are we talking about and what mode do you have the suspension in? I can't imagine this issue having anything to do with RAS.

plasticam

I’m driving in normal and sport, but the feeling is there on both, speeds are 60mph - 80mph

GrantG

Car should feel fine at double those speeds. How are tire pressures?

Maybe alignment is off?

plasticam

Thanks,
Tyre pressure’s are 42psi front and 48psi rear.
It could be the whole car that feels a bit floaty but I put it down to the RAS as it’s the first car I’ve had with it.
kinda feels like it’s on casters lol.

detansinn

Agreed on both points. Check tire pressures first. It's not unheard of for alignment to get messed up during shipping.
It's definitely not normal.

Noah Fect

48 PSI?! I think I see the problem

detansinn

Those pressures are quite high. Unless I am missing something, you're running too much pressure.

plasticam

Thank you,
I’ll drop the pressure’s and test in the next few days.

LexVan

Try 35 front and 39 rear. Then adjust (down 1 PSI) from there. Don't let the tires get above 40 hot. So, let's say you hammer it tomorrow, and the rear tires go to 41 (starting from 39)....bleed out another 1 PSI and try again tomorrow. As air temps continue to rise with the new upcoming driving season, you'll bleed more air out. Then come fall 2020, you start adding air back come October, on.

992TheMoon

Sounds like you have a 4S. Thats the same exact feeling I experienced while test driving a 4S on the highway. Test drove the 2S immediatly after and all felt normal. Both cars were equipped with RAS.

plasticam

Thanks, this is a 2s

Rennolazine

My 991.2 needed MAX 32F/34R cold otherwise it felt like crap to me. Once rear pressures approached 40 psi, the car felt greasy and out of whack

casaforte9

There was a review on you tube ,search for ‘ marek drives 992 ‘ and he mentioned at 18:30 into the video the same thing on 4s but look like it happens on 2s too

detansinn

It’s a tire pressure issue. It can happen on any car. With a high performance car, the impact can be greater.