From www.zhome.com, under "Classic and Collectible Z Cars": The R models were produced by the NISSAN Factory to homologate the large rear wing for racing. This car had to be manufactured in 1000 unit lots to meet the qualification requirements for "Production Class" status. Thus only 1000 were produced. The ZXR was a standard 280ZX coupe with blue stripes on a silver mist paint scheme. The factory registered special edition cost the new owner $399.00 extra.
They ZXR is a zx with no options, power nothing, only turns the alternator and water pump on the engine. More performance, It had no t-tops, it had power brakes, but other wise no power steering, no AC, a true sports car. It also had a spoiler that was capable of 300 lbs of downforce, but i can't remember at what speed. the 79 280zx varies depending on model, if it has PS, and a few other things as well. My 81 280zx is exactly like a zxr, but it does not have the spoiler. So as you add power steering, air conditioning, and so forth, you lose power. Plus the Rack and Pinion steering (manual steering) is much lighter than the other steering, i think its castor or something like that. The is much to it, if oyu have no optnions, power nothing, manual everything, you probably would keep right up with it, but then its the driver who wins the race, not the car =)