I've no doubt that playing with tire pressures can work; lowering the front tire pressure will likely reduce the tendency of the tire to follow minor imperfections in the road, leading to an apparent increase in stability.
However, to me that's not the best way to go about it. It's a little like using morphine to treat an ulcer. It will cover up the pain, but won't address the underlying problem. Each of the 4 variables, tire pressure, toe, camber, and caster, have a specific primary role to play in vehicle handling, and it's best to not get them mixed up.
-Start with tire pressure and set it for load handling (most important), uniform contact patch, fuel economy, and general handling.
- Toe should be set so that the wheels track absolutely parallel and straight at speed. This usually means (at rest) slight toe-in for RWD vehicles (including part-time 4WD), slight toe-out for FWD vehicles, and pretty much straight ahead for AWD or fulltime 4WD vehicles. This minimizes tire scrub and resultant uneven wear.
- Camber is generally set slightly negative (wheels leaning in at the top) for better cornering, although straight line performance is generally better with zero or slightly positive camber.
- Finally, the role of caster is to provide stable tracking and good "return to center" of the steering wheel after a turn. That's its primary purpose. In my mind, that's the place to look if the other parameters are correct and there still is a tendency to wander.
Caster and/or camber are often set to slightly different angles on the left and right wheels to create a bias that counteracts the crown of the road.
However, to me that's not the best way to go about it. It's a little like using morphine to treat an ulcer. It will cover up the pain, but won't address the underlying problem. Each of the 4 variables, tire pressure, toe, camber, and caster, have a specific primary role to play in vehicle handling, and it's best to not get them mixed up.
-Start with tire pressure and set it for load handling (most important), uniform contact patch, fuel economy, and general handling.
- Toe should be set so that the wheels track absolutely parallel and straight at speed. This usually means (at rest) slight toe-in for RWD vehicles (including part-time 4WD), slight toe-out for FWD vehicles, and pretty much straight ahead for AWD or fulltime 4WD vehicles. This minimizes tire scrub and resultant uneven wear.
- Camber is generally set slightly negative (wheels leaning in at the top) for better cornering, although straight line performance is generally better with zero or slightly positive camber.
- Finally, the role of caster is to provide stable tracking and good "return to center" of the steering wheel after a turn. That's its primary purpose. In my mind, that's the place to look if the other parameters are correct and there still is a tendency to wander.
Caster and/or camber are often set to slightly different angles on the left and right wheels to create a bias that counteracts the crown of the road.
