Understanding F1: Insight into FRIC suspension system

The FRIC or Front and rear inter connected suspension is a system which links the front ad rear suspension of the car using hydraulics and aims to provide better stability and drivability for the driver. The system was first introduced by Mercedes in 2011 and for the past two years, they have been working on it to perfect the mechanism.

This year, Lotus have also introduced their FRIC suspension and very recently in China, the Marrusia F1 Team also introduced this system. The FRIC suspension is known to give the driver more confidence in the car and is also very good for tyre management.

So, let’s take a deeper look into the working of the FRIC Suspension.

Whenever a car enters a corner or brakes, it goes through a number of movements i.e, it pitches under braking and rolls while cornering. During these movements, the ride height of the car changes and because of that, significant amount of downforce is lost which leads to instability under braking and while cornering. This is where the FRIC suspension comes in handy as it maintains more or less constant pitch and roll which in turn, leads to more downforce and stability.

The FRIC reduces the pitch and the roll by moving the hydraulic fluid from the front to the rear of the car. So, under braking and cornering, when the nose of the car goes down, the fluid in the rear brings down the back of the car, which in turn brings up the nose and thus maintains a constant ride height.

Another aspect of FRIC is in improving the overall aerodynamic character of the car. The engineers and aerodynamicists always want to run a car with a very stiff suspension. The reason for it is that if the suspension is stiff, the aerodynamic components work better and due to the less movement of the suspension, the turbulence created is less and thus aids in better aero performance.

But the drivers always want to have a soft suspension as car with a softer suspension is much more easier to drive. So, there is always compromise between what a driver wants and what an aerodynamicist wants.

With the FRIC suspension, the cars can be run with a stiffer suspension while not compromising the overall driving comfort for the driver. So, in a way, it indirectly aids the overall aerodynamics of the car and gives a driver more comfort and drivability.

The FRIC suspension works by the transfer of hydraulic fluid from the front to the rear of the car and as the transfer process is passive, the system is legal. Actually, the FRIC Suspension is a replacement for the banned active suspension. The only difference is that the FRIC system isn’t controlled by the driver, it works as the car moves.

Another benefit of the FRIC is that the teams can run the cars very low and with very high downforce levels. Earlier, this wasn’t possible because if the car is too low or has too much downforce, the legality plank beneath the car would wear out due to the tremendous downforce and the constant friction produced from rubbing on the track surface. And, according to the current rules, if the legality plank is worn out by more than 2 mm, the car would be disqualified.

Legality Plank

But with FRIC system, when the car brakes or turns, and as the nose of the car dives down, the hydraulic fluid is transferred from the front to the rear and this transfer forces the rear of the car downwards, bringing up the front, thus reducing the friction between the legality plank and track surface.

Also, as the pitch and roll movements of the car are minimised, the tyres have to face lesser load and thus, the system also aids in tyre management process.

Lotus and Mercedes have been very keen to perfect the FRIC system because they believe that this system will help them in introducing the passively operated Double DRS system which, so far, they haven’t been able to introduce.

The problem with the passive double DRS is that the driver feels insecure about the drag reduction and reattachment and the sudden change in ride height when he’s not expecting it. The insecurity is mainly because the passive double DRS is speed dependent and its opening and closing depends on a particular speed value.

So, if the FRIC could stabilise and maintain a constant ride height, the driver may feel more secure and more confident with stability of the car.