To all XKR and XKRS owners:

I like to drive my XKRS in track mode. That's a habit I got into when I had an XKR because the stability control system was always interfering with the way that I wanted to drive the car. One day after having gone to the local car wash in my XKRS, I took my favorite corner and what should have been not even a little drift turned into a pretty hairy situation. The car went into a severe snap over-steer and I was all hands and elbows trying to save my ***. I was totally baffled. The car had never acted like that before. What I did should have never turned into anything more than a little rear end hop, not even that.

A couple of months go by and I'm at Spring Mountain Raceway spending a day on the track. On my way home I stopped by the local car wash owned by a father and son that hand wash many of the Spring Mountain member's cars. I asked them to put Armorall on the tires and the guy looked surprised and said that they didn't usually do that for the Spring Mountain members who mostly drive Ferraris, Lambos and the like. I asked him why and he said that he was told that it interferes with the handling of the cars.

Four lessons learned:

1) No matter how good you think you are, always leave the stability control system on when in uncontrolled environments (the street)

2) Never put Armorall on your tires if your torque and horsepower exceed 500?

One day after having it applied I drove the 11 miles to work and then looked at the tires. I notice streaks of Amorall on the sidewall going toward and ending at the tread. Theory: The Armorall is thrown by centrifugal force from the sidewall of the tire to the tread having the same affect as oil on the road.

3) When the rear end breaks loose DO NOT abruptly lift off of the gas. Turn into the skid, keep your foot in it while slowly reducing tire spin as the car straightens out. Otherwise you do what's known as a tank slapper.

4) The track mode in the XKRS is much more liberal than in the XKR.

Tank Slapper:

When the rear end starts to slide the direction of momentum causes the gas to go to that side of the tank. If you abruptly lift off of the gas the tires get traction too quickly, abruptly stopping the slide, which causes the gas to slap against the side of the tank and then quickly travel to the other side of the tank causing the rear of the car to follow, possibly causing the car to spin out or go back and forth until it is finally brought under control.

If you think about it, water weighs 62.4 lbs/ft3. 1 cubic foot is 7.5 gallons. 62.4/7.5 =8.3lbs per gallon. I think I did that right. That's a lot of weight sloshing back and forth in your gas tank, (assuming the weight of gas is equivalent to water). Race car drivers have to keep that in mind as the weight of the car transitions from back to front during breaking and side to side during cornering. You have to give the car time to set.

I'm sure this could be explained better. It looks confusing to me and I wrote it. Help Bruce H?!

I was able to keep from spinning but it wasn't pretty.

 

you lift ... you die

 

Thanks I do use the armor all, I will think twice then, yesterday, with the track dsc on, the rear end drift real bad on a slippery road...

 

I like Meguiars Hyper Dressing much much better than Amorall, but I see your point. They are different leagues of product, light-years apart. I'd at least re-wash my wheels after applying Armorall (which I haven't used in 5+ years, minimum).

Wait till you at home to wash your car!

Make sure if you do dress your tires, that they are totally clean after. You should be able to wipe a white cloth on the tire and have it perfectly clean.

 

Hmmm...just *how much* Armor All are we talking about here???

Seems like any Armor All that migrates to the edge of the wheel would be quickly dissipated with just a few revs of the tire on the asphalt.

The inside of a gas tank on street cars has baffles that prevent mass movement of gasoline inside the tank. The gas sloshing from side to side would be greatly attenuated by the baffles. The inertia of the fuel (especially if the tank is near/is full) is still there, however, and would affect the force of the car moving in any particular direction.

 

IMHO it sounds to me that the problem isn't that Armor All was used but, rather, how it is used.

When I use Armor All or other dressings I spray on a light application and immediately wipe away the excess. There's nothing left for centrifugal force to fling.

Seems to me that, in your case, way too much product is being applied to the tires and it's just being left on the tires in liquid state to drip and be slung all over, as you describe.

Or maybe I'm missing something here?

Cheers
DD

 

Doug, that's exactly how I've done it and I never have issues. The problem is when people don't wipe it off. Then it flings all over the place--onto your fenders, doors, etc.

 

It may have been the Armorall that caused your unexpected spin but, I doubt it. In any kind of track driving you should use the warm-up lap to scrub your tires. Following that you should always be on edge during the first full race lap, expecting your tires still not be fully scrubbed and at full operating temperatures. After 2 laps your tire surfaces should be fully scrubbed of any foreign coating of materials.

I also agree with rsculto that fuel slapping should not be a major issue in modern fuel tank construction. I have not seen the construction of an XKR tank but, in case it is not fully baffled there is something you can do about it. You can always stuff the tank with fuel tank foam that is designed to absolutely minimize fuel slashing. I did that not only to my track race cars but to my high performance street cars, as well.

One more advice, if I may; yes, you should counter steer a slide BUT, only to a point. In my practice of spinning many, many times in decades of racing, once the slide goes to about a 45 degree angle, the car becomes unrecoverable. At that point the best thing to do is to bring the steering wheel back to the straight-ahead position and hit the brakes hard. Your spin will complete itself in a predictable manner, which may or may not include hitting something. But, if you keep adding more counter steering, the car will slow and when the tires eventually regain traction the car will produce a secondary spin in the direction to where the front wheels are pointed and this spin will be far more violent than the original one.

Albert

 

My X350 (as do all X350s) had a major problem with fuel sloshing, especially when the tank was low in fuel. Coming to a stop, you would often hear it and feel it "pat pat...".

 

or at least end up pointing in the wrong direction

 

That's a good point and thanks for the tips - good stuff! There are a lot of drivers at Spring Mountain that are not allowing the car wash to put Amorall on their tires according to the car wash owner. It may be an issue with low profile tires.

As far as tank slapping - I was told that by an instructor at the Ron Fellows driving school. I also looked it up online. The term is used for motorcycles but also applies to cars. I would imagine that baffles would help to reduce liquid movement but no matter what you do it's obviously still an issue. Any mechanical engineers from the auto industry care to share?