Porsche 924 Group 4
About 6 years ago the owner of this 924 had the idea to build a high class Porsche 924 group 4 race car, which could be driven as a street legal club sport car to and from the race track. He knew that the factory-specified output of 195 hp from 2 liters was far from being achieved, even in modern youngtimers. So the engine designer set about taking up the challenge with all his expertise.
The owner first bought an accident-free, rust-free, first-paint car. The first thing he did was the engine. The 1979 FIA regulations allowed two Weber twin carburettors and upgraded pistons. The Pistons are special made forged piston which were produced by a Formula 1 Outfitter. The connecting rods are specially made by the main producer for the DTM. However, they were machined, polished and shot-peened. He also uses special connecting rod screws to increase the engine speed. The compression ratio was raised to 12: 1 and significantly larger, new valves were fitted. Inlet 40 mm, outlet 38 mm.
The camshaft is the owner's own profile. Super-light tappets have been fitted, as well as double valve springs. The tappets are DLC coated just like the cams. The cylinder head is machined to the max, all registers have been pulled. 45 Weber carburettors with fine-tuned jetting and matching intake funnels are now running loudly. The oil pan has been modified to prevent oil pressure problems. A "hidden" freely programmable ignition was also installed as well as a large oil cooler. Finally, a complete stainless steel exhaust system with 4 in 1 manifold was custom made to perfectly match this engine. The test bench runs confirm this. The engine has a peak power of 192 hp with a maximum torque of 220 NM from 2L displacement. This engine is far above anything that can be found in modern youngtimer motorsport on our race tracks in other 924s.
The suspension is a Bilstein Coil over system on the front and rear axle.
As the aim was to get the car road legal, new wishbone bearings were used for all suspension parts and uniballs were not used.
In the interior, a Heigo steel cage was screwed in.
The wheels are the fantastic BBS magnesium racing rims in 8.5 x 16 on the front axle and 10 x 16 on the rear axle.
The gearbox was left original, but its tuning fits very well to the strengthened engine characteristics.
For deceleration a 944 brake system was installed on all four wheels which is bolted with 5 wheel bolts.
All these modifications are registered without exception. The car has a German registration.
The body has been fitted with group 4 homologated wheel arches and the front bumper with an integrated spoiler as well as a Group 4 GFK rear bumper.
The total mileage of the car is currently 1,500 km. All parts are completely new.