Making Your Spirit Porsche 936 Fly
by Arie Viewer
The Porsche 936 is one of my favorite LeMans cars. When Spirit introduced their 1/32 scale 936s I was really looking forward to racing them with my race-tuned and modified Fly classic Ferraris, Lolas, and Porsches. The Spirit 936, however, turned out to be a bit shy in the performance department compared with my Fly cars, especially when compared to the ones with a motor pod modified to take a Scalextric bar magnet. So, I set about the task of giving it a performance boost to make it competitive.
The first step, of course, was to disassemble the whole car. Everything went fine until I tried to take the motor out. It just wouldn’t budge from its mount. Finally, after the application of increasing amounts of force, the motor snapped loose…taking part of the motor mount with it. It turned out that one of the factory workers in Shanghai or wherever had been having a bad day and somehow managed to spill some CA glue where it didn’t belong.
Okay, I thought, I’ll just get a new chassis. Not quite. It turns out that Spirit is a little behind the curve when it comes to spare parts availability and no replacement 936 chassis were to be had. Bummer.
Then I remembered that the Porsche 936 was almost the same car, under the skin, as a Porsche 908/3. It was like a 908/3 on steroids, with a much more powerful engine and different bodywork. So, I thought, since I’m trying to make my 936 run like a Fly car anyway, why not see if a Fly B84 Porsche 908/3 chassis and B104 motor pod will fit in place of the original Spirit chassis? When the chassis and pod arrived I began test fitting the various Spirit parts to them. All the mechanicals were a perfect fit; even the wheels and tires were the same size. All the chassis needed to fit under the body was some minor trimming around the edges, a wheelbase decrease of 1/16", and a mounting hole for the body’s front mounting post just aft of the guide.
Photo A shows the mods needed to shorten the wheelbase and create a hole for the front mounting screw. The rectagular slot that the tab on the front of the Fly pod fits into just needs to be extended forward by 1/16". (1). The mounting screw hole (2) really only needs to be just a little bit larger in diameter than the head of the screw, but I made it somewhat oversize so I didn’t have to be quite so precise about its exact location.
Photo B shows the other mods I made to the Fly pod and chassis. The red lines around the edge of the chassis show where it needs to be trimmed slightly to fit under the 936 body. A file, emery board, or sandpaper on a block will do the job. A rectangular piece of .020" sheet styrene (1) has at its center a hole just large enough to insert the front body mounting screw into. (See below for how you get it into its proper location). I gave the pod the same modification I did to my Fly Lola T70 (see article in Electric Dreams News, Aug. 29, 2008), enabling it to hold a Scalextric bar magnet (2). In addition, I installed a Scalextric W8201 press-on plastic spur gear (3), which gives a much better mesh than Spirit’s gear, and replaced the stock rear tires with Indy Grips 3003 silicone tires (4). Later, when test-fitting the body, I discovered that the ends of the stiffening ribs in the chassis interfered slightly with the body posts I fabricated so I trimmed them back a little (5). Sharp-eyed readers will also note that the motor is not the original Spirit unit. I somehow managed to break off one of its lead wire tabs, so I replaced the motor with an extra 18K motor I had lying around, giving the car the same RPM capability as a stock Fly motor. Only items 1 and 5, plus the edge trimming, are really necessary to do the conversion. The rest give the 936 the same upgrades my modified Fly cars have.
The Spirit 936 and the Fly 908/3 both have a body post just forward of each rear wheel. Unfortunately, Spirit and Fly did not put them in exactly the same place. So, I cut the two posts off, glued a piece of Evergreen styrene tubing around ech of them, and reused them in the their new locations. In addition, I had to make a third post, located just forward of the body’s gearbox and exhaust detail assembly, to mount the rear of the Fly pod. The three posts are shown above (Photo C) secured in their positions with epoxy glue. The front body post was used unchanged except for slight trimming. In addition, the headlight buckets (red arrows) were mismounted. I had to grind away their hot-melted mountings and reposition them properly, securing them with CA glue, so they wouldn’t interfere with the fit of the front of the chassis.
To mount the body in its correct location on the trimmed chassis, I attached the three rear body posts to the chassis with their mounting screws. I also fastened the rectangle of sheet styrene to the front post with another screw. I test fitted the body, adjusting the length of the posts as needed to allow the body to sit at the correct height on the chassis. If a post is too long it can be shortened by filing or grinding. If it’s a little too short the inside of the body can be built up with a small piece of sheet styrene. When I had all the posts the right length I mixed up some 5-minute epoxy. I put a generous dab of it at each point where a post was to meet the inside of the body and liberally coated the bottom of the styrene rectangle on the front post. I then carefully positioned the body on the chassis, using rubber bands to hold body and chassis firmly together while the epoxy set. I did the mounting with the axle assemblies in the chassis to help gauge the correct fit but with the motor and lead wires not installed. After the epoxy set up I removed the body screws, installed the motor, and the car was ready for the track.
With its new chassis, magnet, and tires my Spirit 936 is a good match for my modified Fly cars on my Scalextric Sport track. It also is competitive with a Scalextric Ford GT40 running box-stock except for Indy Grips 1010 silicone tires. The Fly classics, the 936, and the GT40, as I’ve modified them, make up a fun racing class that evokes one of the most interesting periods in international sports car racing. In addition, the cars are easy to drive and inexpensive. All night endurance race, anyone?