Introduction - REAR SUSPENSION

The rear suspension has a 'torsion axle' (semi-independent wheels).

The advantages of this solution are:

• similar kinematic behaviour to independent wheels with the relevant functional advantages
• stabilizer function of the crossmember
• reduced weight
• pre-ftting of the suspension before installing it on the vehicle.

The 'torsion axle' suspension is fixed to the bodyshell by two brackets and the shock absorbers.

There are two flexible bushes housed in the ends of the arms known as 'smart' bushes, strengthened with transversely fitted plastic rods.

The bushes are ideal for filtering noise and improving stability round bends (auto-steering). The bushes are fitted at 600 kg on the arms and arranged at an angle of 25°.

SMART BUSHES

SMART BUSHES

A, Traditional torsion axle: round bends the wheel steers through the effect of the lateral force Fy producing an accentuated oversteer effect.

B, 188 torsion axle: under lateral load Fy the wheel steers very little and in a way 'modulated' by the rigidity of the bushes, improves the handling of the vehicle round bends.

There are two types of torsion axles:

• Medium: torsion beam of 2.8 mm

Kinematic resistance to torsion kt 28 kgm

Hard: torsion beam of 3.2 mm

Kinematic resistance to torsion kt 37 kgm

The structural shape and the high resistance properties of the material (FE52) has made it possible to dispense with the anti-roll bar.

The rear shock absorbers are hydraulic, double acting with the mounting under the floor so as not to reduce the width of the load carrying compartment and they are equiped with upper bushes with reduced dynamic rigidity (quality of the rubber) to absorb vertical forces.

Helical springs with end of travel buffers.

1, Bracket fixing torsion axle to the bodyshell

2, Rubber spring upper support seal

3, Coil spring

4, Impact buffer

5, 'Smart' bush

6, Shock absorber

7, Rear torsion axle

8, Stub axle

9, Shoe holder plate

10, Wheel hub

11, Brake drum

12, Hub cap