Anatomy of a Top Fuel dragster


Interesting little article I found the other day about what kinds of mechanical stresses one of those 300mph+ drag racers face each race.

No one really knows how much power the top fuelies have, but the super charger alone uses 700 horsepower of the engine’s output to run

Someone put the explaination about nitromethane in different words, it is just not making it for me.

I think it is strange stuff. It will burn in any mixture (rich, richer, richest) you can stuff into the engine. It’s problematic in that if you put too much in the combustion chamber, it will hydro lock the engine and do real damage. It almost doesn’t need extra air to make it burn. What an effect it has when you light it.

Is it anything like nitros (that releases oxygen when heated)? That popular mechanics explaination about nitromethane makes me wonder if it is considered a fuel or an oxidizer or perhaps a bit of both, it says less btu’s than gasoline but more of it can be pushed into a cylinder, I guess I can grasp that concept.

It’s a fuel, albiet an oxygen rich one. I guess you could say that it’s both combined.

It’s pre-mix oxidizer!
It only takes 1.7 lb of additional atmospheric “air” (~20.9% O2) per pound of fuel versus 14.7 lbs for gasoline. The significantly increased fuel per unit volume more than offsets the lower energy content.

And at a top rate of 95 gallons a minute, they need all they can get.

I also like how the bald guy in the video isn’t wearing hearing protection as he’s walking beside that car.
Someone at work said they done a seismographic study at a drag strip and said when those things take off, it’s like a 3.0 on the Richter scale

Back in let’s say 1983 the drag strip officials here in Tucson allowed you to stand as close to those cars as you dared (think wild west days), I think they got a pretty good laugh out of it. Strip closed down for several years and re-opened with more “corporate” minded management. Buddy of mine lost a driveshaft at perhaps 110 and never drove the car again. He was a much better mechanic than driver. I have seen this several times, when good mechanics built cars that were faster than they cared to drive (or their wifes did not want to be widows).I myself had the livig #$^&* scared out of me at the start of the 1977 Mint 400. Racing is a great fantasy but when you do it for real it is quickly determined who is best left in the pits.

oldschool has got it. I guess what I was trying to say is that gasoline won’t light if the mixture is too rich, and it doesn’t take a lot of it to make it rich. Nitromethane will light under almost any mixture. I had that part right.

Nitromethane is actually pretty difficult to ignite. I put out several kitchen matches in the stuff before finally getting a small tray of the stuff to burn. Then it just sits there and burns with a pale greenish white flame sort of like Sterno.

The fact that it makes good power with a large range of air/fuel mixtures is one reason why it is a popular model airplane engine fuel ingredient. These engines use a glow plug instead of a spark plug to ignite the fuel and the fuel mixture effectively controls the engines ignition timing. A model engine that’s too lean runs a lot like a spark ignition engine that has its spark timing over advanced.

What I find absolutely amazing is how able they are to protect the drivers in the absolutely extreme crashes that sometimes occur. While I intellectually understand the concepts, like allowing the engine and drivetraiun area to seperate from the driver cage and securing the driver tightly into that highly-designed cage, it still boggles my mind. The forces involved are tremendous.

How did making the run shorter than a true 1/4 mile run (shortened too 1000ft) increase safety? Did it simply decrease the time the car spent at it’s highest speed or limit the hightest speed the car could reach? I do know the Kalita crash instigated the reduction in run lenght.

That brings to mind the off-road crash in CA last year. This event seems to have faded from the news. A google search did not turn up any real recent articles.

It means the cars have more room at the end of the track to slow down. Running the full 1/4 would give them 320 feet less to slow.

We have plenty of slow down room in Tucson and the 320 ft would be gone pretty quick at the end of a run. Perhaps the reasoning is more (even if it is not really that much more) slow down room, but I was going with less time to increase top speed achieved.