Edweird wrote:From what I've read as being part of Formula Student, getting 100bhp per litre from a petrol engine isn't a hard thing to achieve. I bet that if you took an F10 and ran it with a set of bike carbs, got a janspeed manifold, custom exhaust got everything tuned just right you could push a hundred horses. You might need to spend a bit of money upgrading the cylinder head to make it last though. (I'm thinking valves, seats and springs)
A 100 HP per litre is easy, my road car is 265HP from 2 litre, box standard.
Now try 1000HP per litre.
One Top Fuel dragster outfitted with a 500 cubic-inch replica Dodge (actually Keith Black, etc) Hemi engine makes more horsepower (8,000 HP) than the first 4 rows of cars at NASCAR's Daytona 500.
Under full throttle, a dragster engine will consume 11.2 gallons of nitro methane per second; a fully loaded Boeing 747 consumes jet fuel at the same rate but with 25% less energy being produced.
A stock Dodge Hemi V8 engine cannot produce enough power to merely drive the dragster's supercharger.
With 3000 CFM of air being rammed in by the supercharger on overdrive, the fuel mixture is compressed into a near-solid form before ignition. Cylinders run on the verge of hydraulic lockup at full throttle.
At the stoichiometric 1.7:1 air/fuel mixture for nitro methane the flame front temperature measures 7050 degrees F.
Nitro methane burns yellow. The spectacular white flame seen above the stacks at night is raw burning hydrogen, dissociated from atmospheric water vapor by the searing exhaust gases.
Dual magnetos supply 44 amps to each spark plug. Which is typically the output of a small electric arc welder in each cylinder.
Spark plug electrodes are totally consumed during a pass. After 1/2 way thru the run, the engine is 'dieseling' from compression and the glow of the exhaust valves at 1400 degrees F. The engine can only be shut down by cutting the fuel flow.
If spark momentarily fails early in the run, unburned nitro builds up in the affected cylinders and then explodes with enough force to blow the cylinder heads off the block in pieces or split the block in half !!
Dragsters reach over 300 MPH +... before you have completed reading this sentence.
In order to exceed 300 MPH in 4.5 seconds, a dragster must accelerate an average of over 4 G's. In order to reach 200 MPH well before reaching half-track, at launch the acceleration approaches 8 G's.
Top Fuel engines turn approximately 540 revolutions from light to light!
Including the burnout, the engine must only survive 900 revolutions under load.
The redline is actually quite high at 9500 RPM.
THE BOTTOM LINE: Assuming all the equipment is paid for, the pit crew is working for free,
& NOTHING BLOWS UP, each run will cost an estimated $1,000 per second.
0 to 100 MPH in .8 seconds (the first 60 feet of the run)
0 to 200 MPH in 2.2 seconds (the first 350 feet of the run)
6 g-forces at the starting line - nothing accelerates faster on land (except a “strap” slot car Ed.)
6 negative g-forces upon deployment of twin 'chutes at 300 MPH
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An NHRA Top Fuel Dragster accelerates quicker than any other land vehicle on earth . .
quicker than a jet fighter plane . . . quicker than the space shuttle....or snapping your fingers !!
The current Top Fuel dragster elapsed time record is 4.420 seconds for the quarter-mile (2004, Doug Kalitta).
(I think the time is now closer to 4 seconds, M.)
Ever wonder why a Top Fuel dragster gets a rebuilt engine after each run?
The top speed record is 337.58 MPH as measured over the last 66' of the run (2005, Tony Schumacher).
Let's now put this all into perspective:
Imagine this...........You are driving a new $140,000 Lingenfelter twin-turbo powered Corvette Z-06. Over a mile up the road, a Top Fuel dragster is staged & ready to 'launch' down a quarter-mile s trip as you pass. You have the advantage of a flying start. You run the 'Vette hard, on up through the gears and blast across the starting line & pass the dragster at an honest 200 MPH.... The 'tree' goes green for both of you at that exact moment. The dragster departs & starts after you. You keep your foot buried hard to the floor, and suddenly you hear an incredibly brutally screaming whine that sears and pummels your eardrums & within a mere 3 seconds the dragster effortlessly catches & passes you. He beats you to the finish line, a quarter-mile away from where you just passed him. Think about it from a standing start, the dragster had spotted you 200 MPH.....and it not only caught, but nearly blasted you off the planet when he passed you within a mere 1320 foot long race !!!!
That, my friends.....is acceleration.
That might just spoil the handling of your SJ though.
but there's no replacement for displacement so who cares about a small weight increase vs 50ish more HP. I was thinking about a h25 but there's two guys in the US with samurai's, one has the v6 the other the 4pot, the 4pot leaves it standing! Plus I should be looking at close to 130bhp with a decat exhaust and the 2.5 v6 isn't that much more powerful, think it's only 25-30bhp more and not a huge increase in torque either but heavier.
