Originally Posted by rcs950racer
What is different between Kyosho Evolva 2003, 2005, and M3?
The 2003 car was the baseline Evolva. The 2005 car featured a change to the front suspension that allowed for shortening the wheel base from the front.
You didn't mention the 2007 car, but it featured a change to the rear suspension, in the body mount area. The arms were also changed, but you could get the same from the 2003 rear arms.
The M3 is a totally different car. The chassis was narrowed and all the pickup points for the rear were moved further inboard to allow for longer rear arms. The new rear design also featured adjustable wheel base so the car could be shortened at the rear. It still used the front suspension from the 2005 car, but the bulkheads were moved further inboard to allow the front suspension arms to be longer. The front and rear bulkheads featured excentric bearing carriers so that belt tension could be adjusted. The outboard hubs for the front and rear axles also now have excentric bearing carriers so that the roll center can be adjusted at the wheel. The servo saver was changed to widen the adjustment window.
Also, you didn't mention the M3 EVO. It is another iteration of the M3. They came up with some new pulleys for the rear that offered more FDR combinations than the previous models. The 2-speed is also redesigned to use a C-clip to retain the spurs rather than the screw and washer of the previous models. The 2nd speed spur is now mounted on a redesigned drum that can be removed and placed on another spur. That is so the shift point doesn't change when you change 2nd speed ratios.
That is all I can think of off the top of my head. I am sure that some others will jump in an add so smaller level improvements that I have omitted.