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NHRA Fuel Racing
The TF/FC engine is basically a reciprocating rocket engine. It requires an investment of around $100,000.00. It uses forged aluminum pistons and billet aluminum rods and a compression ratio of 7:1 to produce an estimated 7,500 to 8,500 hp. A Conventional dyno is useless and would just break plus require longer than the 4 plus seconds these babies are designed to run. A team will inventory around 15 forged aluminum; bare blocks at $7,500.00 a piece.
NHRA rules limit the cubic inches to 500 and the throttle housing to a maximum of 65 square inches, 20 times the area of NASCAR.
TF and FC engine are basically the same except a FC engine is required to run a dry-sump oil system for safety reasons. Funnys are tuned slightly less aggressive than a TF because of the greater traction issues due to its shorter wheel base. Its rpm ranges from the NHRA limited cap of 8,250 to 6,500 to 7,000 at about 2.5 to 3 seconds into the run right when the clutch is going to 1:1 producing a maximum torque in mid run like 6,500 lbs/ft.
Although today’s fuel engine is very loosely based on and has its roots in the “64-71” Mopar 426 Hemi, but it shares no parts, almost nothing in principles or practice with it. It has evolved making it stronger, safer, and capable of more power and very easy for just 7 men to overhaul in the 40 minute maximum next round racing.
Fuel is a mixture of 90% nitro and 10% methane. Nitromethane contains only ¼ the heat energy of gasoline, however requires only 1/8 as much air to complete combustion. So when everything is right, it makes 4 times the power.
Fuelers carry 18 gallons of fuel at $30 a gallon. About 13.5 gallons of fuel are consumed over the 2 minute lap, including start up, burn out, staging and the race. The actual “run” uses 4.5 to 5 gallons. Approximately a gallon per second which is roughly the same rate as a 450-ton Boeing 747 jumbo jet. A waterman four section, two stage, fuel pump is used to deliver 93 gallons per minute. Around three tens into the race, at 8,250 rpm’s the engine is using 55 GPM and at 2 seconds, between 73 and 85 GPM. 42 fuel-injector nozzles are used throughout the intake system: 10 in the blower hat,16 in the intake manifold and another 16 in the cylinder head. 2 crank-triggered 44-amp MSD magnetos fire the 16 spark plugs, two per cylinder. Electronic engine controls are forbidden in NHRA Fuel racing which also limit the engine to a single roots type blower. Typically the boost is 42 psi off the line and 52 to 53 psi at the finish line.
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