by Larry Roberts
October 23, 1998
There was a time when amateur road racing drew large albeit mostly local crowds but the proliferation of professional racing has depleted those numbers. Its too easy to stay home and watch NASCAR on TV.
But far from being moribund, amateur racing on road courses is as popular as ever and its ranks of drivers increases every year.
One problem that faces entry-level amateur racers is the type of car to compete in without having to mortage the family farm. While go-karts are fast and inexpensive, they're still racers that roll on small wheels and are dwarfed by their drivers. Single seaters like Formula Ford 2000 are also fast but require lots of maintenance and money to be competitive. Other classes (and there are 64 in the San Francisco SCCA region that I call home) have their own drawbacks but it seems that one class had a built-in advantage: it's a one-make "spec" series for early Mazda RX7s and it's probably the most inexpensive method of getting into racing available. And the thing that amazes non-enthusiasts is that the engine in the RX7 has no pistons or valves - its powerplant is the enigmatic Wankel rotary.
As a company, Mazda has been around a long time in Japan but it didn't start making cars and light trucks until after World War II. To begin with, its engines were pretty conventional with pistons, valves and camshafts but in 1961, the company made an agreement with NSU, a German motorcycle and auto maker, to build its very unusual rotary engine for use in Mazdas.
The design was the brainchild of Felix Wankel, a German engineer who developed the unique powerplant that bears his name. A Wankel uses two three-sided rotors in a pair of side-by-side trochoidal chambers and operates roughly like a two-stroke piston engine but without pistons or a crankshaft. NSU had a short run of rotary-powered sports car in the '60s but it was Mazda that put the rotary on the map and the race track.
The first rotary Mazda to hit our shores was the R100 coupe in '71 and it was indeed, a homely and flimsy little mutt of a car that had just one thing going for it: its tiny 1000cc engine put out 100 horses which was enough to allow the 2100-pound car to stay with all but the quickest V8s at stoplight drag races. Along side the minuscule R100, Mazda brought in a more refined RX2 and later the RX3 two door sedans.
It didn't take American speed merchants long to learn that the Mazda rotary could be tweeked and ground on to produce two and sometimes three times its original horsepower. Installed in suitably modified RX sedans, the performance of the engine was phenomenal and SCCA Mazdas won countless races in the early and mid '70s.
But Mazda really made its mark here in 1978 when it introduced its RX7, a true sports car in the classic sense. It only seated two people and in close quarters at that. It was low, sleek and lightweight. It held the road tenaciously and was an immediate best-seller. Soon the hopped-up 1300cc rotary engines that had been developed for the racing of Mazda sedans found their way into race-readied RX7s.
The original somewhat Spartan RX7 went out of production in '86, replaced by an updated, more modern sports car that bore the same RX7 name. It too was raced successfully but not in such great numbers.
When Ford bought a majority share of Mazda some years ago, it marked the end of the rotary engine. It was too "dirty" smog-wise and too expensive. The Mazda sports car mantel fell to its Miata roadster.
But the original RX7 with its powerful but cheap rotary engine has spawned its own class that has spread like a wildfire through amateur sports car racing. Three clubs in the West have RX7 classes and in the San Francisco Region of the SCCA, 33 identical cars challenge the championship. The racing is fast and close and each win is a hard-fought battle.
Amateur sports car racing is still expensive but if neophytes go with Mazda RX7s, the don't have to win the lottery to be competitive.