[Guest]

I have a 2002 575m with New no

I have a 2002 575m with New novatech 19 inch and pirelli 355 back 255 front.
Up to 80 mph--steering is like butter--after 80 I get a slight vibe and I can see the hood start to rattle.

Balancing shows 100%

Any comments?

Any feedback greatly appreciated.

 

[Guest]

Paul,

Welcome to Ferrari-Ta

Paul,

Welcome to Ferrari-Talk....

Having been down this road numerous time with different high performance cars and tires...it usually all come back to poor balancing and/or equipment.

First and foremost, a "road-force" type balancer is a must...

The wheels should be mounted on the balancer using the stud holes, not the hub center to locate the wheel.

With big, low profile tires....the balancer should be verified for accuracy/calibration first.

A "bad" tire, or out of round wheel can be "balanced"....but at some speed(s), a vibration will occur. Do not discount a "bad" tire (excessive road-force) as a possiblity.

If all checks out "OK", check the front wheel bearing for looseness....and the brake rotor/hub for excessive runout. This too can cause a high speed vibration.

Regards,
David

 

[Guest]

David -
what kinds of places

David -
what kinds of places typically have a road force balancer?
thanks
Russ

 

[Guest]

Russ,

I find that virtually

Russ,

I find that virtually all BMW, Audi and Porsche dealers have them...Hunter is the key player in the road force machines.

In 2001, I bought a new Carrera...and shortly after purchased, I complained of a vibration in the rear of the car. Their Hunter machine picked up a "excessive road force" (out of round under load) tire. Short story, they replaced the rear tires with 7 "new" ones before they got a good one! But, they did finally get rid of the vibration. Sadly...I hated the car anyhow!

Regards,
David

 

[Guest]

Check runout and roundness of

Check runout and roundness of the wheels, then check runout and roundness of the tires. Every once in a while one tire in a set can arrive out of round, and every once in a while a wheel can be warped from impropper torquing of the wheels to the hub.

 

[Guest]

there are a hundred problems t

there are a hundred problems that can be found when balancing tires & wheels, the machine, the personel, the tire, the wheel, the hub, a wheel bearing, it goes on & on.

But like advised, the first course of action is always to rebalance and recheck the wheel & tire combo to make sure they both run true & round. Insure against any undulations both in the wheel & tire as it's spun up to speed.