Reply to "Measuring Chassis Height & Shock Adjustment"

I can only share my experience in the alignment and corner balance of my 911SC track car. My Pantera hasn't been done yet.

They put the car on the pads of the scales. The ground or the rack has to be perfectly level. The car will have half a tank of gas and they place the weight of the driver in the drivers seat.

They then look at the weight of each corner. Each corner will be different.Race teams etc will go to great lengths to get the 4 corners the same in the shift of fuel tanks, battery relocation or ballast if the rules allow so.They then take a corner say the right front and then look at the left rear. They then start adjusting the ride heights. The car is really sensitive to this. For example raise the passenger front you now raise the passenger rear.You also upset the other 2 corners.Its sort of taking a sheet of square wood and placing a ball in the center. Drawing a X to all 4 corners. Each car has its own weight bias characteristic or weight bias distribution. For instance in the 911 case its more 60/40 because the engine is in the rear.In the Pantera's case I think its 50/40 because its mid engine design.

So they are adjusting ride heights, trying to get the weight bias of the car correct and doing an alignment all at the same time.It really is half rocket science and black art. Not so easy. It takes an experienced person to do this. As Rapid pointed out, get it right and seconds come off your lap times.Get it wrong and your car has a pull to the right or the left that can be mistaken for a bad alignment.The car will also develope a front end skip during really hard corning.You'll be fighting a bad corner balance the whole way through a turn.All this is done for the car not the drivers style of driving.Thats why they have sway bars for fine tuning.

This is just for a roadracing circuit. Circle track or oval track racing opens up a whole another can of worms and experience.Its really important you don't take your car down to Rayco's for this procedure.You can but you'd never fully exploit the true handling of the Pantera at speed.

As I mentioned, it is a mechanical science to it.Its why they charge so much money for it to be done correctly. I've only explained in what little I know.They have books of explanations and theories of this stuff.

As far as the Pantera I payed Pat Michals a lot of money up front. He refabricated all four corners of my upper control arms so I have as much room possible in setting up the suspension without bind.George is right when he says don't lower the rear of the car past the level of the lower control arms. If you do, You've used up most of the travel of your shocks. You end up with a bucking bronco.Having extended upper rear control arms is a cheap advantage in setting of the rear for the correct castor.

Dan