The difference between driving a 360 that has a poorly set up suspension compared to one with the correct settings is like night and day. Setting up the suspension geometry can be done at home but I firmly believe that it is best left to someone with the correct equipment and that means a proper machine to accurately measure the wheel angles (see my “Recommended” page for a link). Here’s a picture of one of my cars on the ramp having its geometry measured – the machine in use here is a Hunter and is the same as Ferrari use in Maranello.
Ferrari specify the suspension geometry in four areas: Toe, Camber, Castor & Height. All are interdependent so changing one will affect the others. The specifications are for a fully loaded car – that means a full tank of fuel and a 70kg static load in both the driver and passenger seat:
The height of the vehicle is the first parameter to be set. Ferrari measure the height from the floor/level the car is sitting on to specific points on the chassis. For a stock 360 the height is 125.2mm at the front and 146.8mm at the rear:
Here’s a picture showing the chassis measurement points in more detail:
Many people opt to lower their car, myself included. I went for Challenge Stradale specifications, 110mm front and 130mm rear. Changing the height of the car is straightforward as the springs have adjustable platforms. Hill Engineering sell a tool to adjust the lock nut: Hill Engineering The platform can be adjust in situ, however I prefer to remove the shock/spring assembly from the car. It takes a little more time but you can then compress the spring, rotate the spring platform, measure the change in height and ensure the rubber mount that the spring sits on is OK with ease. With the shock absorber out you might want to consider changing the lower bush: Link
If the height of the car is altered then the camber of the wheels will change. Camber is how much the top of the wheels lean into (or out of) the car from vertical. For a standard 360 Ferrari specify -1.01 degrees at the front and -1.26 rear. This is negative camber, which means the top of the wheel will be leaning slightly into the car. In general, negative camber gives better cornering but too much camber will be at detriment to straight line braking and acceleration performance. The Stradale has slightly more camber than a standard 360 (-1.28 & -2.00) and this is what I have my car set to.
Changing the camber is a non-trivial exercise – it is altered by inserting or removing shims between the bottom wishbone mountings (flamblocs) and the chassis. Increasing the width of the shim pushes the lower wishbone outwards and thus the top of the wheel leans into the car more. The process runs like this: measure camber, jack up car, remove wheel, undo wishbone, insert/remove shims, refit wishbone & wheel, lower car & re-measure the camber. It is an iterative process so having an experienced person perform the adjustment will save time (and costs). The benefit of doing the adjustment this way is that once it is set correctly it is set period (barring any chassis trauma).
The castor angle (caster in the US) is specified by Ferrari as a fixed 6.3 degrees. Castor is the angle between the pivot angle of the wheel and vertical when the wheels are pointing dead ahead. The angle is determined by the shape of the wishbones and should, in theory, be perfect regardless. In practice castor isn’t always to spec but someone experienced in setting up geometry should be able to recover the angle when setting the camber.
To set the camber alone, shims are inserted/removed on both lower wishbone flamblocs by an equal amount. Varying the shim adjustment between the two flamblocs will alter both the camber and the castor. By adjusting two angles together the number of iterations to get things right generally goes up but once it’s done, it’s done.
The last parameter to be changed is the toe – Ferrari specify the wheels to be toe-in both front and rear. Toe-in provides high speed stability as the wheels are trying to turn towards and against each other which means (on a flat surface) the car will not change direction unless the steering wheel is turned. Toe-in does impact how a car turns into a corner but for fast road and occasional track use I recommend staying with the OEM spec (1.25mm front, 1.5mm rear). Front toe is adjusted in the same way as any other car – by changing the length of the steering rack track rods. Rear toe is set in the same way, by changing the length of the rear track arms.
More info on different geometry settings is available in this excellent post by 360Trev: Ferrari Chat