amazing drag racing engine statistics...

9500RPM on an engine that size is pretty damn incredible , as are that other fatoids !!

 

Say what you will about Road Racing vs Drag Racing.

I've stood on the starting line during Nitro burnouts, the ground shakes!

Funny Car drivers are some of the bravest people on the planet (followed closely by Top Fuel drivers).

 

The other amazing thing to me is they completley tear it down and rebuild the engine between each run. So not only does it perform, but it has to be built to come apart quickly, but not prematurely.

Ken

 

You mean the earth moves !!! These machines , bombs or whatever you want to call them are simply incredible. I'll be heading to an event next month ,can't wait!

 

FWIW: That came from a magazine a few years back, can't remember which one. Either Road & Track, Car & Driver or Motor Trend - I've got it somewhere at home...

 

Top fuel drag racing is incredible. The drivers are insane to strap themselves into one of those things.

It takes ~400 hp to drive the supercharger. That's one hell of an air pump.

Top fuel launch presses the driver into the seat with about 8 g's of force. When the parachute deploys 5 seconds later the driver is subjected to about 3 g's into the harness. Nice 11 g spread from start to finish!

At the 60' mark the dragster is going over 100 mph. 0 to 100 mph in a little more than 3 car lengths! Ridiculous.

No engine dyno in the world has been built that can measure the power output of a top fuel engine. Most estimates put the peak power at around 8000 hp.

 

The average stechiometric ratio is about 18:1 for gasoline engines.
1.7:1 must be a typo for one, and I would also agree that 9,500 rpm for engines with reciprocating masses of such size and weight is hard to believe.

 

.....not to mention the 44 amps (?!) to each spark plug!

 

Stoichiometric combustion for gasoline-fueled engines is approximately 14.7:1.

For nitromethane it is indeed 1.7:1. Much less air needed for full combustion than with gasoline. At full throttle it looks like a fire hose pumping fuel into the cylinder.

 

It is not a typo. Nitromethane engines run much richer, which is part of the reason they make so much power.

 

Nitromethane carries its own oxygen, that affects the air/fuel ratio and is part of the reason the fuel shutoff is so important.

 

Correct

I saw the fuel line on a top fuel dragster once.... it was aproximately 2.25" diameter ....

 

That's not exactly true, they dyno ship and train engines every day. The guy who sits across from me ran a 26,500hp dyno 30 years ago and says the dyno in the other building was close to 40,000hp. Appearently they brought fuel in by the barge....a truck of fuel wouldn't even get the engine warmed up.

 

Probably not too many units like that out there.

I'll bet the crankshaft speeds measured were in hundreds of RPM's.

 

They where running 4000 rpm turbines, but since they were ship engines, they had a gear box to get them to a max or 200 rpm, thats the story anyway. It was a water brake dyno with aluminum blades and appearently it had to come apart every 100 hours to weld the blades back up.

I don't think the issue with top fuel engine is that you can't dyno them, it's about the cost to dyno them. You can run the engine for 5 seconds on the dyno at a couple grand a second and not get paid or take it to the track and get paid and learn almost as much.

 

I once knew a motorcycle jumper named "Super Joe" Einhorn. He told me that he never practiced a jump. It made no sense to do it without paying customers present.

 

Guess I should have said "automotive engine dyno".

Also, top fuel and funny car teams do practice and testing runs all the time at the track. Even - maybe especially - with no spectators or other teams present. It's an expensive sport considering how little time is actually spent competing. A 5 race ladder only has about 25 seconds of actual racing if you are the winner. Only about 5 seconds if you are eliminated in the first heat.

 

Oh, Oh , I know, you could hook the chute to a rope that is wrapped around the shaft a generator........

 

You could probably safely say they are not friendly to anything or anyone!

 

Tell me about it.
I can remember as a teenager walking around the pit area of Fremont Raceway when it was still open. There were a bunch of people standing around a top fuel car, waiting for the pit crew to test start the engine. Although everyone was about 10 feet away from the car, I thought I'd be a big shot and walk right up to the engine, seeing that I had some earplugs jammed way up into my ears. When they fired it up, the zoomies shot a blast of raw nitromethane right into my eyes. Let me tell you how not fun that was...

 

I do not believe those engines are making anywhere near 8000 HP. 2500 HP popped Garlits through the traps at 250 in 5 seconds. A doubling of HP should pop one of these cars through at roughly 50% higher speed. This takes no consideration into the fact the cars today are wind tunnel designed and maybe have only a fraction of the drag these cars had 35 years ago when the engine was in front, not to mention that todays machines are also much lighter.

Just imagine what kind of times they could have trapped with one of these modern cars if it were detuned down to 2500 HP. I bet it would still trap through at over 280 MPH.

 

No, actually physics don't work that way. It's logerithmic. To double the speed you have to SQUARE the HP. All other things being equal...

Think about it; my 120 HP car at 1500 lbs goes 0-60 in ~7 seconds. If I had 240 HP I would NOT be at 3.5 seconds; I'd be more like 5.

Ken

 

Ken is correct. Found this online for what it's worth:

DRAG FORCE ON A ONE-SQUARE FOOT SQUARE PLATE


Speed Drag Force Horsepower Required
to Overcome the
Aerodynamic Drag
0 mph 0 pounds 0 hp
100 mph 33 pounds 9 hp
200 mph 133 pounds 71 hp
300 mph 299 pounds 239 hp