944 and a 944S

What is the difference in these two models?

For the 944 S, there were 4-35mm valves per cylinder opposed to 2-38mm valves on the 8 valve head. Fuel pressure was 55 PSI from the 36 PSI on the standard. Since knock suppression is key for a high compression motor, Bosch M2.1 Motronic digital engine management was employed. The 944 S has 2 knock sensors over the 944 Turbo's 1 sensor. The sensors are located below the head between cylinders 1-2 and 3-4. The Motronic engine management system monitors each sensor as the cylinder fires. If knocking is detected, the ignition is retarded in 3 degrees steps with a max of 9 degrees. The transmission is the same as the 944 Turbo, with taller ratios for the lower gears, compared to the std 944, and a shorter top (5th) gear. The final drive ratio is 3.89 for the 944S and 3.38 for the 944 Turbo. In retrospect, Porsche admits they could have geared it longer for better fuel consumption. However, the final drive ratio was selected to place the 944 S in the middle of the std 944 and the 944 Turbo.

The 944S is the sportiest in the 944 range versus a more "grand touring" attitude from the 944 Turbo. The 944 demands more from a driver who wants to extract it's best. The 944S was also the first Porsche car to be offered with dual airbags as an option. Aside from a modest badge on the rear of the car, only the optional "16 Ventiler" scripts on the raised side strips will alert anyone that there is something special about this 944. However, with the hood up, the 16 Valve head is an obvious giveaway.

LeMans, June, 1981, the 50th Anniversary of Le Mans, a special car was developed and raced under the guise "924 GTP Le-Mans". By specification, this car was no 924. The car - in full race trim - was powered by a DOHC 16 Valve 4 Cylinder with a KKK turbo with a 4 speed gearbox producing 410 BHP at 6500 RPM. The car had a top speed of 180 MPH down the Mulsanne Straight. Driven by Barth & rally driver Rohrl, the car took 3rd place in the Open Class and 7th overall out of 55 starters and only 20 finishers! The car also won the award of spending the least amount of time in the pits at only 56 minutes out of the 24 hour endurance race. This was the only time in the history of the 924/944/968 line that a turbocharger and a 16 valve motor were used together until the 944 Turbo S , but that's a different story altogether.

In pure technical terms, the 944 S takes it's basic engine block from the std 944 and it's DOHC 16 Valve head from the 928 S4, while borrowing some sophisticated electronics from the 944 Turbo (951). Why 4 valves per cylinder? 4 valves per cylinder became neccessary when cunsumption and emissions regulations were tightened. It also gave Porsche a chance to develope it's "1 car for all markets" strategy. As a result, power figures for the 944 S are the same regardless of country sold in. Any difference in performance from one market to another are a result of different testing methods, not the car.

Porsche built the 944 S to round out thier "three tier concept". The 944 S was placed strategically between the std 944 and the 944 Turbo. The 944 S was also built to give Porsche an Autobahn edge on thier home ground. The 944 S will run all day well above 125 MPH with little more than tire noise to disturb your stereo

The 944 S model line was only produced for two years and was discontinued in 1989 when the 2.7 litre engine was put into the 8 valve 944s. The 2.7 litre 8-vavle motor produced almost as much power as the S model.