Huron 4A Cosworth DAF Variomatic, by Wouter Melissen, via UltimateCarPage
It was a rainy Tuesday when I got a tip from Monkey10is that DAF had a history of racing. A machine I’d never heard of called the Huron 4A Cosworth DAF Variomatic. A quick search turned up an article by Wouter Melissen. Real enough. That’s where I found the first picture. Seems DAF already had some experience in Formula 3. Never mind their reputation for making innocent-looking two-cylinders named Daffodil. Wikipedia noted, quote ‘interesting’ low speed behavior when ice was around. And it’s an open secret that at top speed, slowly releasing the gas will make Daffodil go faster instead of slowing down. But I was more interested when Wouter mentioned an AWD DAF 555 prototype in passing. As if such a thing can be mentioned in passing.
DAF 55, by Anrie, via Wikimedia Commons
It was time to go to the archives. Google Translate detected RallyDaf.nl as Russian, so I had to switch it over manually to Dutch. Before the Huron, a DAF 55 completed the London-Sydney Marathon. The 555 was built in parallel with DAF’s open wheel experiments, and used the same F3-spec of the Variomatic along with Gordini and Lotus 4-cylinders that would give the rubber bands more than 63hp worth of slip to limit.
The AWD 555 was built by the de Rooy brothers in three weeks using notes from the back of a cigarette packet. An old test report said they put engine transversely where the passenger would be, the transmission where the driver would be, the driver in the middle with a chain back to the steering column. Is there nothing de Rooys wouldn’t do? They made it switchable betwen 2WD and AWD. They could have 4-wheel traction or avoid getting busted down on a time penalty. But the biggest shock was the spider differentials front and rear. BMW 2002, of all things. Later versions put the engine back in the front, and the driver back on the left where he belongs, but another diagram found on RaceHistorie.nl confirmed the crazy layout of the ‘bump’ car.
DAF 555 AWD ‘bump’ car, via racehistory.nl
I went for a fresh cup, mainly because I needed a napkin to do my own scribbling. I’d expected a belt drive for each wheel, two Variomatics, eliminating the dependent relationship of spider gears, where revs spike when a wheel spins and you need three diffs. Instead, the belt drives replaced the transmission and the center diff of an otherwise standard path from piston to tarmac. The AWD was a red herring, and a moot point anyway because the FIA banned it. The real benefit of that CVT was keeping the lump in its powerband, not so much the finer points of vehicle dynamics. The DAF racers could have more power, more of the time, and pull a gap everywhere but the peak.
Low end power sells cars, top end power wins races.
On the other hand, it’s easy to see how skimming a couple of percent here, a couple of percent there, and all of a sudden you’re losing ground instead of gaining. But things are never that simple. If you get rid of the need to pull at the low end, idle, or even rev up smoothly, an engine can make a lot more power in a very narrow window.
It all came together in 1993. Hub Van Doorn himself, who founded DAF and created the Variomatic, helped the Williams Formula One team develop a belt-drive CVT. It was enclosed to prevent slipping in the rain, beefed up for the power, tested, and banned by the FIA before it could ever race.
Williams FW15C, via RET Monitor
In this game, any time they make up new rules just for you, you’re doing well. Maybe a little too well for the people who would rather keep you on the straight and narrow.
I never reveal my Sources:
[1] Monkey10is
[2] UltimateCarPage.com, article and images by Wouter Melissen
[5] DAF 55 – Wikimedia Commons
[6] RallyDaf.nl – Great galleries of vintage DAF photos
[7] Motorsport Magazine, Page 36, 1972
[8] racehistory.nl – make sure to scroll through every single fender flare
[10] Race Engine Technology – Formula One CVT Part 1, Part 2
