Steyr Puch 650 TR was meant to be faster than an Abarth 500. Probably like the BMW, as it could rev better being opposed rather than a pair upright. Although the NSU has got advantageous cam drive. They are safe to 7,500 revs. They chose not to offer much in the way of a tuned 600cc twin. Simpler to go 4 pot. But they never did a Sport Prinz with that engine. Instead the Wankel came in and is technically in class despite that the car morphed into the Syder. You could get a high compression top end for the 600cc later unit. The BMW certainly performs well for a package that at first glance looks a bit suspect. I do not doubt the chassis is well tweaked to get the handling. I believe the Martini cars were looking at at least 75 bhp out of 700cc. John Bannell is on about that, if he wants it, with his more modern resourced injection version. The dark horse might be from Japan, who could just squeeze something like a Honda 600 in with bits from the Motorcycles on. Front wheel drive would suit certain courses. Then you have the Enfield Berkm perhaps rather hailing from an earlier era but sporting front wheel drive.
However these are not really microcars in the old terminology. For shear toughness in ralles and enduro events the Goggo did well. Do not forget the Berkeleys, fragile they might be, but good running, in experienced hands, these are serious little racing cars. The triple would see off the competition on a circuit, I think. Not so sure when you turn to long course. Ken Piper proved a good driver in a Tiger can put in very good performances. The Tiger is more rugged than a Berkeley but again you have a fragile engine. The difference is the Excelsior tends to fail terminally, the TG500 tends to wear but keep going, meaning a rebuild after each serious event. It is part of the Tigers attraction as it was a giant killer in its day.
