Zoals je zelf al aangaf; druk op de voorwielen vergroten

Straight line stability and side wind sensitivity were problems on the early Porsche 911's. Some reasons were the heavy engine in the rear and the fact that the center of pressure was located far ahead of the center of gravity.
To a certain extent, this can be solved with proper suspension and aerodynamic aids. Porsche wanted to increase the moment of inertia both around the cars vertical and longitudinal axis. In order to do this Porsche added a total of 11 kg, in some cases even 22 kg, in the front bumper outer ends. The extra weight was named “reinforcement of front bumper” and was sometimes added without notification to the car owner. The problems decreased but adding weight on a sports car is not very suitable and could only be regarded as a temporary solution.

From the beginning Porsche 911 had 165 HR 15 tires on 4,5 inch rims. On the A-series model from 1968 the same tires were fitted on 5,5 inch rims. Together with reduced caster angle some improvements in straight-line stability was achieved.
To gain a better weight distribution, heavy parts were moved to the front and parts in the rear were made lighter. On the B-series model, for model year 1969, two smaller batteries placed in the front fenders replaced the single one. Both engine crankcase and gearbox were made of magnesium instead of aluminum. These modifications, together with an extended wheelbase (57mm), gave a front/rear weight distribution of 43/57 percent.

The 911S were equipped with 185/70VR15 tires and tuned for a less under steered behavior. Porsche believed that the customers for this higher performance model had the required driving skills. The B-series reflected the intense development that had been going on since the introduction of the 911. This model is known to have good handling performance but the straight-line stability and side wind sensitivity were still not sufficient.

The E-series, model year 1972, was equipped with an air dam below the front bumper. Air dams are used to lower the front stagnation point and thereby decrease the pressure under the car, especially in the front, which reduces the lift forces. Since the pressure is lower underneath the car then on the sides, air will be sucked in from the surrounding. The effectiveness of an air dam therefore decreases towards the rear end of the car.

Aerodynamic measurements on an E-series model shows that front-end lift was reduced by 40 percent but rear lift force was not affected at all by the use of an air dam.
In 1972 Porsche wanted to match the 911 with the group 4 regulations. The regulation states that the general body contour must remain unaltered. To be allowed to fit a spoiler on the group 4 homologated cars Porsche needed a standard car with the same features. The car to meet the
challenge was the Carrera RS, model year 1973. This car was Porsches first road going car with a rear wing and wide rear fenders. The wider fenders enabled the use of wider tires in the rear than in the front. Porsche Engineers had wanted to do this for a long time in order to take care of the
heavy load on the rear axle and the increased power since the first introduction.

De 'airdam' waarover ze het hebben in combinatie met de S-bumper...

Ik heb al enkele oude 11-jes gehad en zoals mijn huidige vooraan strak op de weg ligt heb ik ze nog niet meegemaakt. Vorige eigenaar had dan ook "turbo tie rods" gestoken, nieuwe schokdempers gemonteerd (koni) + de auto is correct uitgelijnd. Mijne heeft geen "spoiler" vooraan. Of de rubbers van de torsieveren / A-armen zodanig slijten dat die best ook vervangen moeten worden weet ik niet, ik neem aan van wel ? Ik weet niet of ze bij de mijne vervangen zijn.