whiteout 5.0

anyone i talk to no matter who i ask. Everyone knows they push 5000 hp no one knows how they do it. It's not like a fully race prepped small block with a twin turbo kit that makes 800hp. its not like pro mods, or even pro stock where you have your engine builders. I've never got the chance to talk to anyone in top fuel but its always been a HUGE question. HOW DO THEY DO IT?

Demon 340

nitromethane, plus lots of boost.

a "normal" street engine runs on an relative optimal air to fuel ratio of 14ish to 1. nitromethane is actually a type of oxygenated fuel, so it has a relative combustion ratio of 2 to 1...so they came cram a great deal more air and fuel in, which makes for better combustion, and more power.

yes, i know that this isnt a perfect explanation, so before anyone jumps me for not using proper decimals, i thought that this would explain it simply enough.

snakeman4life

$$$$$$$$$$$$$$$$$$$$And they don't make 5000hp,they make over 7000hp.

whiteout 5.0

what displacement do they use? i know they're 8 cylinders, are they small blocks? what do they shift them at?

Demon 340

the funny cars have to run 2V, one cam,with a maximum cid of 500...with a roots supercharger. i believe that the top fuel rules are the same.

snakeman4life

And every one of them[that I know of] is "based" on the 426 Hemi,however there is nothing dodge about them,they are all aftermarket aluminum blocks with little in common with the original Chrysler hemi except the design of the heads.Add to that huge 14-71 superchargers with over 50psi of boost,and of course nitromethane,which at full throttle they burn somethine like 2 gallons per second[at $20+ a gallon],and you basically have the most insane internal combustion engine in the world.Plus they are pretty much the loudest thing you will ever hear in your life,period.BTW supercharged Pro Mods have similar motors but run on methanol,so they "only" make 3000-3500hp,just because of the fuel.I remember reading a few years ago it costslike$4000-$5000 just to make 1 pass with a top fuel car,and that was a few years ago,and thats not hurting any parts,which they do quite often.

Clif Brohn

Its all in the gas. Not to mentio they theoretically make insane amounts of cubic inches.

Look at it this way. Nitro Methane to gasoline is like lighter fluid to jet fuel.

Also, as stated above, they run about 50psi. The amount of atmosperic pressure pushing air into a motor is 14.7psi. So 14.7psi of air fills the 500ci big block. If you run a supercharger at 14.7psi, then you are effectively running 29.7psi of air into the engine, thus creating 1,000ci. Another 14.7, thats 44.4psi, and 1,500ci. So in theory the nitro cars are running super octane fuels through a 1,800ci motor thats inside a ridiculously light car. I dont know how light, but its LIGHT.

And thats aboot the jist of it.

Demon 340

ive never heard it described like that....interesting.


i will say, that for those of you who havent seen an NHRA top fuel or funny car make a hard pass....youre missing out. it is an awesome experience.

Boss_Hotrod

As far as shifting them goes there is no gearbox. They run just a poile of clutches (I think 5 or so). The car basically just slips all of the clutches down the track until it reaches 1:1.

Demon 340

i saw a few of the fuel cars run a couple months ago, and after EVERY run they replace the clutch assembly...at least at that event they did..

were the hell is birdieman? he has a 4 second car, if im not mistaken.