Four wheel alignment on road going cars is an area that I have failed to understand, despite several posts explaining same. So far as my knowledge goes if you alter any aspect of a car’s geometry it will have a knock on effect somewhere else. It therefore follows that if the vehicle does not have fully adjustable geometry then it is not possible to accurately achieve the manufacturers’ or your own preferred settings. You can only rely on the manufacturers’ build to be “straight”. Also, I would have thought that it is very important to have the rear wheels following the front wheels. This is something which cannot be achieved on a road car because it would necessitate being able to move the whole rear end or front end one way or the other. In other words setting each corner does not necessarily mean that the rear wheels are following the front wheels. You have to rely on the car being straight in the first place. I don’t see how the rear end can communicate with the front end in the sense that it is capable of moving as a whole. You could have each corner reading exactly correct but not following/leading each other. If the laser/what have you, is capable of finding the centre of the car and sees that something needs to be moved, in the sense that the car is “crabbing”, it cannot be done. I suppose the bottom line is that it doesn’t matter that much on a road car, but it’s still an interesting subject to discuss. I can easily understand how some basic adjustments can be achieved. What I can’t understand is that if the rear wheels are not following the front wheels what can you do about it. It seems to me that four wheel alignment is a bit of a fudge and should be called four wheel setup.
Joe
