Auto Racing: Racing handicapping, sports car club, engine displacement

Question
Hi Dan,
I hope you can help!
I race historic cars in the UK  and have been for 15 years. However we have been trying for a while to work out a handicap system so that we can race equally will different cars.
Do you know of a formula that exists where we can input variables such as weight/power/frontal area etc. - so giving us a equal base to start from.
Cheers,
Roger

Answer
Greetings from the Colony
Good morning Roger !!

Within my club, , Sports Car Club of America, there are provisions for vintage cars.  The classes are based primarily upon engine displacement as related to vehicle weight, and secondarily upon  performance potential.

The club being what it is , occasionally chooses to re-classify a particular car to eliminate competitive advantages.  That system seems to benefit the largest number, and though there are exceptions, I hear very few complaints. Those re-classifications can be based up on a variety of factors, but lap times seem to be one of the more popular ones.

Using frontal area ?   What about advertised compression ratio ?  Overhead cam vs. varied pushrod arrangements ?  You can never make it entirely fair,  the AC Bristol compared to my old Triumph TR-3 wasn't a match, and they both had pushrod arrangements.  All I ever saw of those cars were the taillights !

In our club's racing they seem to be more preoccupied with having the cars reflect their era.  My neighbor's Porsche 356 must run treaded tires, while others are allowed slicks. And on our short course at Sebring , he takes a fierce beating from a Fiat 850 Abarth .

The best handicap system I have ever seen though,  was based on practice laps.  Each car had a mandatory pit stop, but the length of that stop differed with cumulative lap times.  So a car that was a second faster, would have 20 seconds longer in the pits in a 20 lap race.  If a competitor then starts running significantly faster than his practice times, he is disqualified.

In one such race, my 20 year-old son bested a couple of 700 horsepower, 200 MPH Chevrolet Camaros, this in a 1600 cc Datsun Sunny .

So that's what little I can contribute, I hope you continue to enjoy the greatest sport on the planet !!!

Sincerely

Dan Liddy
Sarasota,Florida USA