There is no doubt that the Porsche 917 is one of the best looking race cars ever built. That being said, when you are working in 1/24 scale, the choices are somewhat limited. I purchased one of the many 917,s that are out there on the web right now at pretty good prices for a big slot. Unfortunately, the Carrera version, although a sharp looking car, is rather clunky and slow out of the box at twelve volts. Sure, I could just turn up the volts on the power source, but unless im running it against another Carrera, it just plain wont cut it. I set out to find the problem, and tore into the 917 with a vengeance. First thing I found was the terribly oversized, under powered motor that Carrera uses in there 1/24 cars. here is a picture of what I think came out of a cordless drill, and Carrera used them to power their big cars.
The photo shows it next to an NSR king motor that I am going to install to even the score on the track with my other cars. I tested both motors at 12 volts, and the pic shows the results I got. After dis assembly, I found Carrera uses a bolt in motor like our scratch built cars! I swapped out the Carrera pinion to the nsr motor, and did a test fit. the motor plate (plastic) holes don't line up. But using the outer most hole to set gear mesh, I simply filed the other hole to be able to use the other mounting screw. Bang! fit right up!. I used a dremell and cutter bit to remove a little plastic from the motor carrier, and all fit up just fine. I reassembled the rear axle/motor assembly and re soldered the motor wires to use the Carrera plug. I then turned my attention to the guide to remove the centering spring. I don't use them on my wood track. No issues there, about like their 1/32 counterpart. I trued the factory rear tires for now, and re assembled the beast for a test run. First lap told me I was on track(no pun intended) with my motor choice. I like to stay around 21,500 with my motors, but the 917 was heavy, and needed a little more punch to be competitive. the tested 22,500 motor dropped it right in line with my others. So, although most folks don't like buying an RTR car, and then having to work on it, when you have a wood track, you just expect it most times. I ended up with a smooth runner, and a damn fine looking car in my opinion, that runs with the rest. hope this helps someone. oh yea, and fc motor would be easier to adapt, but I had a few of these NSR takeouts to use up. motor choice would be up to the individual.