One of our projects is taking a 1982 924 and making it into a competitive SCCA ITB race car. We hope to have it on track in May for a shake down, then competing in June.
The beginning of the story was several years ago when we acquired a shell of a 924 Turbo with the cage already installed – one of the best cages that I have ever seen in one of these race cars. That in itself saved a lot of headaches in building a new car – the cage. As it was a Turbo, it already had five-lug suspension in place and four-wheel disk brakes – a good start.
The plan from the beginning was to assemble it back with only those parts (weight) that it had to have. We also wanted to optimize the rules and build it with the best parts and pieces while staying legal. So we started by transferring a race suspension from a 924S ITS car into the body, including the brakes.
About the brakes…the original 924 had a dual circuit brake system, but it was a diagonal system with the RF/LR and LF/RR each on a circuit. Staying within the rules, we changed the master cylinder to a stock 944 master cylinder, then replumbed the front wheels on one circuit and the rears on the other circuit as found in the 944/924S cars. The brake line from front to rear is routed through the inside of the car on the right side of the tunnel rather than under the car – better protected from debris. And all the hard lines will be new, as well as the flexible lines. With rebuilt calipers and cross-drilled rotors, the car will definitely stop.
With the brakes solved, the next question was the suspension. With Koni adjustables on all four corners, the rear is held up by 28mm torsion bars. The fronts are coil-over units with 325 pound springs. With the strong springing, keeping the Weltmeister sway bars front and rear wasn’t an option – we instead decided to mount 944 Turbo sway bars. But,
there was one issue – the front sway bar mounting was different between the early 924 and the later 944. And since the early sway bar mounts to a tab on the early 944 control arms, and those arms are no longer available, we put new steel control arms on the car with plastic bushings. The turbo sway bar mounts on the control arms, but then attaches to the front subframe via some custom steel brackets that we made. They seem to mount just right. Whether this combination will work properly is still unknown – we will find out soon enough. The math works out, but who knows?
The stock steering came with a 924 manual rack, which looks pretty small and weak. So, since we changed over to a 944-esque front suspension, we decided to use a de-powered 924S rack with new tie rods and ends. However, mounting for the 924 vs 944 rack is different – the same idea, but in different locations on the front crossmember. So, Ideola Garage and Dan Beckett to the rescue! Dan set us up with a pair of adapters that bolt to the 924 front crosssmember and allow the mounting of the beefier 944 steering rack. All done!
So it will stop and steer – what is left but to make it go?
The engine is about ready to go in. Since we have a collection of turbo vs NA parts, and the body is a turbo, it is set up for a hydraulic clutch. We will use the turbo bell housing to accommodate it. The engine is basically stock, bored .40 over, with new or reconditioned parts. We have a second engine (in pieces, of course) with new Euro pistons that we will build into a spare later. Basically, we are looking for something around 110hp that is reliable but strong. We will use a radiator from a 944, which is larger and affords better cooling capacity. We found a tutorial from Dan Beckett at Ideola Garage on how to make brackets to mount it up – with the 944 fans.
The electrical system is all new with a custom harness that we made from scratch. Autometer gauges, including a shift light, are part of the package, with all switches and fuses on the dashboard in plain and accessible sight. The dashboard will come off with only ten bolts, and the entire car electrical system is housed on the front and back of the dash, making upgrades and repairs a snap.
The cage includes some nice NASCAR bars in the doors, so the inner door steel is gone to allow for the bars. We will use a good race seat since neither of us are little guys.
The theme for the car is from our sponsor, which is our own business – CJTraining.com. We are trainers and consultants for police agencies, so we decided to paint the car like the 924 police cars that the German police used back in the day. So, that is what we will have. I am hoping for a cover photo on the regional SCCA magazine!! (We already have the rear tag, complete with the proper German government seal and the seal for Stuttgart.
So keep a watch on this progress as we attempt to break into the enduro championship race for 2017…starting in October!
See you at the track!