DBrian

It's like a tire grinding or shuffling at low parking lot speed, hard right or left turn, more evident when slowly braking during the turn. Dealership claims the negative camber contributes to this phenomenon and that nothing can be done about it.
I realize we have about a 1.5-degree negative camber in 2011-and on IS-F (I have no mods and still running with stock Potenza RE-050s), perhaps this contributes to the feel of the tires at parking speeds. Its a fairly minor nuisance but anyone else experience something like this?

SpeedFreaksUSA

iTrader: (1)

That shouldn't have anything to do with camber. I street drive my track car with more than -3 degrees of camber and have never experienced what you're describing. To me it sounds like toe is more of your issue. Have you had the car aligned recently? Do you know what your alignment is (or should be)?

Matt M.

Sylvan

iTrader: (6)

I agree as I read I was thinking the toe is likely out

ISFPOWER

iTrader: (20)

wheel bearing or a slightly sticking caliper.

lobuxracer

iTrader: (2)

It's a combination of a lot of caster and likely toe not exactly happy. The F has a pretty tight turning radius too. I notice this most below 45F OAT on summer tires. I had hoped replacing the rear LCA bushing would eliminate this, but it only minimized it. I still get some suspension noises from the tires at high turn angles and parking lot speeds.

That's the long winded way of saying, "it's kind of normal."

nicklausw

Is the tire worn evenly? Does it have any unevenness that could cause chatter? 1.5% of camber is not going to cause issues if the toe is correct. Did you check the caliper or pad?

clarionguy

I have the same issue. at far turn radius and slow speed / parking lot I thought I was rubbing the inner plastics - but seems it is the tire.

If you ever look at the geometry of the tire from outside when it is turned fully you will be surprised at the angles

SubOrbital

Yup! Is that caster or camber that you see when the wheel's turned?

DBrian

Wow thanks for all the inputs and sorry I've been offline for a few hours. To answer some of you, I've just had this car about 2 months, and it has just 31k miles so no I've not had an alignment done. Although it seems to track very straight at all speeds. Both The front tires have extra wear on the inner shoulder of the tire and for a while I also worried they were rubbing against something but not sure about that yet. The Lexus mechanic said this sensation is not unusual but it's more pronounced on some is-Fs more than others...
Other than the inner wear on the fronts, the tires all seem to be wearing evenly and there's plenty left on the brake pads.

mikersoft

iTrader: (1)

Before you get new front tires, I recommend you upgrade the rear LCA bushings.. They should eliminate the extra wear on the inner shoulders. Also, they greatly improve the car's stability under heavy braking.

-Mike