GT Project

When we started the Viper GT project we had only tested our system  on off-road vehicles. Computer simulations with racing cars showed that the same principle was valid and that very similar advantages were possible when the dynamic analysis was made in comparable terms (stiffer suspension rates, higher speeds and smaller road irregularities). In theory, we could make the car more stable, and bring more corner grip.

To go from theory into facts was a challenge for CREUAT, but also for GLPK team, who at that point were already satisfied with the conventional system they had used successfully so far. Nevertheless, the need to keep being competitive drove them to take the bid.

We ended up designing a system that would not only provide a much harder spring and damping rates, but that would also permit more adjusting refinements. The system should work in harder conditions, like nearby engine and brake high temperatures, and at the same time stand dynamic loads and lateral accelerations of a true race car. Altogether this brought us into a radically different design of a system 

Initially the system was provided with more elements than needed, so it could have more possibilities to be adjusted. This included 18 gas chambers that provided the spring means for all the vehicle movements and 24 adjusters for the damping. Unbelievable enough, the overly complex system did work from the first time without failure on a car that had 650hp engine and reached 250km in the Zölder track. 

To configure they system the first time we had to carefully measure the vehicle dynamic characteristics. To correctly damp the roll movement, we needed to know not only the roll spring rate, but also the inertia to roll. We did so for the roll movement, the pitch movement and the vertical movement, damping each movement with the optimal damping rate that would maximize tire adherence.

Axle crossing stiffness is controlled separately. The system developed for the Viper implements the same weight distribution unit as in all our other prototypes. This means that as soon as the system is pressurized, each wheel receives the weight it should have. The GLPK team does not have to spend any time in the wheel weights adjusting procedure. The scales reveal a 50%/50% diagonal weight distribution so they are no longer needed for the race adjustments.

The system central device is provided with a valve that permits the selection of two operating modes. The first mode configures an isostatic weight distribution. In this mode, the axle crossing is completely free, and the scales would also measure 50%/50% diagonal weights. The second mode includes a slight stiffness of the axle crossing, which is used to change also the front/rear roll stiffness, and therefore the understeer rate. We use this valve to configure the two major suspension configurations, the first used for wet track conditions, and the second for dry track conditions. The team is then able to quickly change from one mode to the other with no other changes in the suspension, thus within the small time they have to replace tires from one type to the other. 

At the present time the tests carried out show already some advantages in some of the different situations in the race track  when compared to the previous used conventional system. We expect to finish the setup and to start using it on races not too far from now.

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