Bilen

Top Fuel Dragster är den snabbaste klassen inom dragracing. Det är inte ovanligt att bilarna kör tävlingssträckan (402 m) från stillastående på under 5 sekunder och med sluthastigheter upp mot och över 500 km/h. Bilarna drivs av kompressorbestyckade V8-motorer med cylindervolym på max 8 194 cc. Som bränsle används en blandning av maximalt 90% nitrometan och runt 10% metanol.

Motorerna kan utveckla upp till 8 500 hästkrafter med ett vridmoment på 8 135 Nm. Vid maximal kompression använder kompressorn 400 hästkrafter. Den höga effekten leder till stora påfrestningar på motorkomponenter och motorerna byggs om fullständigt mellan varje lopp.

Avgasutblåsen som riktas uppåt bidrar till att trycka ner maskinen mot marken och öka vidhäftningen av bakdäcken med så mycket som 3,6 kN. Spolern bakom bilen är ännu effektivare och kan vid farter på runt 500 km/h öka marktrycket med 53 kN. Bilarna har bara två växellägen; framåt och bakåt. För att bromsa bilarna används bromsskärmar (liknande små fallskärmar) som släpps ut precis efter mållinjen. En Top Fuel Dragster har en hjulbas på mellan 7,112 meter och 7,620 meter.

Specifikationer

MOTOR, V8 500 cu.i. • KOMPRESSOR, SSI 14/71 • MOTORBLOCK, Brad Anderson • EFFEKT, 8000hp+ • INJEKTOR, CBD • TOPPAR, Brad Anderson • BRÄNSLE, Nitrometan 90% • BRÄNSLESYSTEM, Waterman • VEVAXEL, Velasco • PRESTANDA, 0-100km/h ~0.6 sec • TÄNDNING, MSD Ignition • KAMAXEL, Erson • RACEDATOR, Racepak • KOPPLING, AFT 5-disks • KOLVAR, Venolia • CHASSIE, ME Racing Service AB • BAKAXEL, Chrisman • VEVSTAKAR, Brooks • DÄCK, Good Year • VENTILER, Manley • VIPPOR, Stage V Engineering • BROMSSKÄRMAR, Simpson

Motor, V8 500 cu.i.

The engine used to power a Top Fuel drag racing car has its roots in the second generation Chrysler Hemi 426 “Elephant Engine” made 1964-71. Although the Top Fuel engine is built exclusively of specialist parts, it retains the basic configuration with two valves per cylinder activated by pushrods from a centrally-placed camshaft. The engine has hemispherical combustion chambers, a 90 degree V angle; 4.8″ bore pitch and a .54″ cam lift. The configuration is identical to the overhead valve, single camshaft-in-block “Hemi” V-8 engine which became available for sale to the public in selected Chrysler Corporation (Dodge, DeSoto, and Chrysler) automotive products in 1952. The block is machined from a piece of forged aluminium. It has press-fitted, ductile iron liners. There are no water passages in the block, which adds considerable strength and stiffness. Like the original Hemi, the racing cylinder block has a long skirt (to reduce piston “rocking” at the lower limit of piston travel). There are five main bearing caps, which are fastened with aircraft-standard-rated steel studs, with additional reinforcing main studs and side bolts. There are three approved suppliers of these custom blocks. The cylinder heads are machined from aluminum billets. As such, they, too, lack water jackets and rely entirely on the incoming air/fuel mixture for their cooling. The original Chrysler design of two large valves per cylinder is used. The intake valve is made from solid titanium and the exhaust from solid Nimonic 80A or similar. Seats are of ductile iron. Beryllium-copper has been tried but its use is limited due to cost. Valve sizes are around 2.45″ (62.2 mm) for the intake and 1.925″ (48.9 mm) for the exhaust. In the ports there are integral tubes for the push rods. The heads are sealed to the block by copper gaskets and stainless steel o-rings. Securing the heads to the block is done with aircraft-rated steel studs.

Kompressor SSI 14/71

The supercharger is a 14-71 type Roots blower. It has twisted lobes and is driven by a toothed belt. The supercharger is slightly offset to the rear to provide an even distribution of air. Absolute manifold pressure is usually 3.8-4.5 bar (56-66 PSI), but up to 5.0 bar (74 PSI) is possible. The manifold is fitted with a 200 psi burst plate. Air is fed to the compressor from throttle butterflies with a maximum area of 65 sq. in. At maximum pressure, it takes approximately 900 horsepower (670 kW) to drive the supercharger.

Motorblock, Brad Anderson

The cylinder block or engine block is a machined casting (or sometimes an assembly of modules) containing cylindrically bored holes for the pistons of a multi-cylinder reciprocating internal combustion engine, or for a similarly constructed device such as a pump. It is a complex part at the heart of an engine, with adaptions to attach the cylinder head, crankcase, engine mounts, drive housing and engine ancillaries, with passages for coolants and lubricants. The distance between the cylinder bores (midpoint to midpoint) cannot easily be changed since the machining facilities would require extensive modification. Instead, the bore (diameter) is commonly varied to obtain different engine displacements. This and the minimum thickness of material required between two cylinders are a limiting factor concerning the potential displacement because the bore to stroke ratio has to stay within certain limits. Engine blocks are usually made from cast iron or, in modern engines, aluminium and magnesium.

Toppar, Brad Anderson

In an internal combustion engine, the cylinder head (often informally abbreviated to just head) sits above the cylinders on top of the cylinder block. It consists of a platform containing part of the combustion chamber (usually, though not always), and the location of the poppet valves and spark plugs.

Effekt, 8000 Hk+

Hästkraft, hk, fysikalisk term, definierad och introducerad av James Watt. Gammal enhet för effekt, numera ersatt av watt. Hästkrafter används dock fortfarande av tradition inom många områden, bland annat för att ange fordons motoreffekter. I Sverige är hk ledande enhet för detta, medan man i många andra EU-länder använder kW mer än i Sverige.

Chassie, ME Racing Service AB

A Top Fuel chassis — which usually has a wheelbase of between 285 and 300 inches is fabricated from 300 feet of 4130 chromoly tubing and costs between $30,000 and $40,000. For the price, the customer also receives front spindles, a steering box, seat, floor pan, motor plates, rear-end plates, wing struts, a body, fuel tank, brake handle and master cylinder, clutch pedal, fuel-shutoff and parachute-release levers, control cables, oil-overflow tank, and, in most cases, front-wing and nose assembly. The chassis alone weighs approximately 600 pounds.

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