Unimaginable Acceleration What actually happens when you light off your Top Fuel dragstel. I ONCE CHATFED BRIEFLY WITH THE IATE PETER GREGG AT A PORSCHE Club mction, and I mentioned that the Mercedes-Benz I was driving that weekend was a lovely road car and a wonderful cruiser, but it lacked really startling acceleration. Peter gave me a sidelong glance and said, Its been my experience that straightline acceleration is probably the first aspect of automotive pcrirmance that any intelligent driver gem bored with. Ever since that day probably thirty years ago, his statement has Crossed my mind as I nailed the throttle in some Porsche 91111rbo or Meroedcs-Bcnz $600 and giggled like an idiot. It crossed my mind again when I received the following email, forwarded from my great 'icnd Mr. William Neely. Bill Neely and I have been enjoyingdrch others companysinoel rst took over an andan magazine in 1962. Since that time. he has Written about ajillion magazine pieces and some three dozen books. including Stand on It, the ctional memoirs of the infamous Strokcr Ace, which he cowrote with our mutual friend the late Bob Ottum. Here is the e-mail: Subject: Top Fuel Dragsters I One "lop Fuel dmgsmrs soc-cubic-inch l iemi engine makes more horsepower than the rst four rows at the Daytuna 500. I A stock Dodge llemi v-s engine cannot pror duos enough power to drive the dragsters supercharger. I With 3000 CFM of air being rammed in by the supercharger on overdrive, thc fuel mixture is compressed into a near-solid form before ig- nition. Cylinders run on the verge orhydmulie lock at full throttle. I At the stoichiometric 1.7:1 airrfuel mixture for nitronrethane, the ame front temperature measures about 7000 degrees Fahrenheit. I Nitromethane burns yellow. The spectacular 52 iu'rohionilsr; white ame seen above the stacks at night is raw burning hydrogen, separated from atmos pheric vtatcr vapor by the scaring heat ofthe exhaust gases. I Dual magnetos supply44 amps to each spark plug. This is the output ofan arc welder in each cylinder. I Spark plug electrodes can be totally Conr srrmcd dunnga single pass. After halfrdistanoe, the engine is dieseling from compression plus the glow of exhaust valves at 1400 degrees Fahrenheit The engine is shutdown by cutting the fuel ow. I Ifa spark plug fails early in the run, un- burned nitrn can build up in the aected cylin- der and explode with suicient force to blow the cylinder head offin piwcs or split the cylin- der block in half. I In order to exceed 300 mph in 4.5 seconds, dragsters must accelerate at an nvemge of more than 4 gs. In order to reach 200 mph bcforc hultldistance, the launch acceleration approaches 8 g's. A Top Fuel dragster reaches more than 300 mph before you have complet- cd reading this sentence. I With a rcdline that can he as high as 9500 rpm, Top Fuel engines turn approximately 540 revolutions from light to light. Including the burnout, the engine needs to survive only 900 revolutions under load. I Assuming that all of the equipment is paid off, the crew works gratis, and nothing breaks, each ion costs an estimated $1000 per second. I The current Top Fuel dragstcr- elapsed time record is 4.441 seconds for the quarter-mile (October 5, 2003, Tony Schumachcr). The top speed record is 333.25 mph as measured over the last 66 feet of the quartermile (November 9, 2003, Doug Kalitta). I Putting all of this into perspective: You are driving the average $140,000 Lingenfelter twin-turbo Corvette zoo. More than a mile up the road. a Top Fuel dragster is staged and ready to launch down a measured quarterrmile as you pass. You have the advantage ofa ying start. You run the Vette up through the gears and blast across the starting line and past the dragster at an honest 200 mph. The tree goes green for both of you at that moment. The dragster launches and starts after you. You keep your foot down. but you hear a bmtal whine that sears your eardrums, and within three seconds, the dr-trgsrer catches you and beats you to the nish line, a quarter-mile from where you just passed him. From a standing start, the dragster spoued you 200 mph and not only caught you but nearly blasted you as the road when he passed you within a more 1320 feet. That doesnt sound too excruciatingly boring, now, does it? I called my equally good friend Don Prieto, of Lhe Prieu've Group in 'Ibmnce, California, to check the facts He suggested that the business about heat from dragster exhaust igniting the hydrogen in the atmosphere was probably hypothetical. Prieto then reminded me of a factoid he had passed along in the days of frontengined dragsters. He said, You know that youre in deep trouble in a dragster if you can suddenly see things clearly. That means the supercharg- er has been blown off the top of the engine and the law nitromethane iel has eaten through your visor." Prieto haswrimm a tem'tic history of hot rods called Hat Rad Chronicle, and if anybody can capture all of that, it would be my pal Prieto. The book is beautiful as well as instructive. published by Publications International Ltd. Well worth your attention. 1.1 MARCH 2004