TAdriven98

iTrader: (2)

Technically speaking what causes the flames out of the headers on top fuel cars and funny cars?

1BADFNZ

I imagine it's because its a really short open exhaust and it's just the fire in the engine (make sense??)

boondiggys

iTrader: (165)

i would agree but also the fuel burns hotter??

1BADFNZ

Well hell remember they don't give a rat's *** about emissions, fuel economy, wear and tear of the engine... just one thing POWER

So yeah they run seriously high power and don't burn gasoline.

camaronutt

iTrader: (1)

I beleive they burn alcohol, not sure which type, I'm not familiar with such high tech fuels. But it does burn hotter, but going in it almosts frosts the intake, so I think it cools well too.

technical

It's nitromethane. I don't think they cut it down either. If you watch closely when they start the engine the crew chief will spray some gasoline into the injector because you can't start the engine on nitro or it will expode.

Actually it's only the throttle plates that want to ice up because of the low pressure area in front of them. That huge blower is sucking in some serious air.

hourang

iTrader: (6)

i thought alcohol was burned cooler?

technical

Yes it does, but we're talking about cars with large displacement, large blowers, and no cooling system. So by the time they actually make their pass, they're hot...real hot!!

Colonel

They're shoving so much nitromethane through these monsters that it's still burning even after the exhaust stroke.

REDLV SS

Found this on a website...

At stoichiometric (exact) 1.7:1 air/fuel mixture (for nitro), the flame front of nitro methane 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

technical

So they actually burn the air around the car!?!?!?!

Taco

iTrader: (1)

Top Fuel and Funny Cars both are limited to (Yeah, I know, limited...) 90 Percent Nitro Methane, the other 10 percent would be methanol I believe. Up until last season, they could run up to 98 percent, but NHRA is trying to cut back the number of oil downs (i.e. engines exploding!), and also trying to shorten the between-rounds down time for the "Professional" Classes (T/F, F/C. P/S, P/SB, P/M) for Television reasons.

That is a really cool explanation of the Flame colors, I hadn't thought of it, but that makes sense. They are, in a nutshell, igniting the air just outside the headers....

I wanna drive one!!!

Taco

BlackBowtie

You can also see flames on NASCAR cars. I believe the reason there is that the higher the octane, the longer it takes the fuel to burn. Therefore, the fuel is still burning on it's way out of the exhaust. On the contrary, the flames on a Fast and Furious car are like a butane setup, just for looks.

But have you guys ever been in the pit of TF/FC? OMG! I was right next to pit crew when they just finished rebuilding the engine, and they fired it up. Nitromethane filled the air, and it burned my eyes so bad. That stuff is brutal.

technical

It's left over unburnt fuel that ignites in the hot exhaust usually on decel when the engine runs richer.

hourang

iTrader: (6)

yeah i was just referring to the previous posts that said the fuel burned hotter which it doesnt and is not the reason you see flames.

REDLV SS

Here is the rest the website has for cool info. on top fuel cars:

TOP FUEL DRAGSTERS INFO

One dragster's 500-inch Hemi makes more horsepower then the first 8 rows at Daytona. Under full throttle, a dragster engine consumes 1 1/2 gallons of nitro per second, the same rate of fuel consumption as a fully loaded 747, but with 4times the energy volume.

The supercharger takes more power to drive then a stock hemi makes.

Even with nearly 3000 CFM of air being rammed in by the supercharger on overdrive, the fuel mixture is compressed into nearly-solid form before ignition.

Cylinders run on the verge of hydraulic lock.

Dual magnetos apply 44 amps to each spark plug. This is the output of an arc welder in each cylinder.

Spark plug electrodes are totally consumed during a pass. After 1/2 way, the engine is dieseling from compression plus the glow of exhaust valves at1400 degrees F. The engine can only be shut down by cutting off it's fuel flow.

If spark momentarily fails early in the run, unburned nitro builds up in those cylinders and then explodes with a force that can blow cylinder heads off the block in pieces or blow the block in half.

Dragsters twist the crank (torsionally) so far (20 degrees in the big end of the track) that sometimes cam lobes are ground offset from front to rear to re-phase the valve timing somewhere closer to synchronization with the pistons.
To exceed 300mph in 4.5 seconds dragsters must accelerate at an average of over 4G's. But in reaching 200 mph well before 1/2 track, launch acceleration is closer to 8G's.

If all the equipment is paid off, the crew worked for free, and for once NOTHING BLOWS UP, each run costs $1000.00 per second.

Dragsters reach over 300 miles per hour before you have read this sentence. * Top Fuel Engines ONLY turn 540 revolutions from light to light!

The redline is actually quite high at 9500rpm.

To give you an idea of this acceleration, the current TF dragster elapsed time record is 4.477 seconds for the quarter mile. This means that you could be coming across the starting line in your average Lingenfelter powered "twin-turbo" Corvette at 200 mph (on a FLYING START) and the dragster would BEAT you to the finish line FROM A DEAD STOP in a quarter mile distance!

I belielve a new current record was set this weekend at 4.42

technical

Sorry 'bout that, somehow I skipped over that post...