Banks Top Dragster assembly photos
- Thread starter jbarker@bankspower
- Start date
i have always wondered this but why does banks always use parallel turbos? they could use twin compound setup like the 7.3 dragster does, that is bad a$$
x2
and you would think drive pressure would be much easier to manage also . you can see each turbo is gated to the atmosphere as well .
????? Tank full of meth. We were talking about nitrous; the need for it to spool up the parrallel turbos. Water meth is for cooling
Methanol (alcohol)
I want to see someone fill the tank on that car with pump fuel at the pump for that matter.
I want to see someone fill the tank on that car with pump fuel at the pump for that matter.
Are you at all aware of the fact it would take 248% MORE alcohol then diesel to make the same amount of power? Further, adding it to diesel would displace the same percentage of diesel fuel per injection event making LESS power then diesel alone.
Last edited:
And here's why:
Methanol, as a fuel, has a lower energy density (15.6 MJ / L max) than both gasoline (octane, 34.6 MJ / L) and diesel (cetane, 38.7 MJ / L).
Ref: http://en.wikipedia.org/wiki/Energy_density .
Per unit of fuel injected, methanol makes less power than either gasoline or diesel.
However, it (methanol) will burn somewhat efficiently at very rich mixture ratios - rich of it's stoich, possibly lower than 6.0:1.
Gasoline engines typically lose efficiency under 12.0:1 (as a nice round number).
Diesel engines will gain power until they reach the lean-burn limit of the fuel, typically over 30:1. We have measured this.
Methanol is also highly resistant to detonation, allowing higher compression ratios / boost and more aggressive ignition timing.
Doing the math, and using gasoline as a baseline:
Methanol volume to equal gasoline power potential:
34.6 / 15.6 = 2.22, or 220%. Over 2.2x the amount of methanol vs. gasoline required to achieve the same energy potential.
Methanol volume to equal diesel power potential:
38.7 / 15.6 = 2.48 or 248%. Over 2.4x the amount of methanol vs. diesel required to achieve the same energy potential.
In normal racing gasoline engines, the limiting factor to power generation is the amount of oxygen present in the cylinder at combustion.
Airmass / fuelmass = air:fuel ratio
If you're stuck on airmass, your only option is to add more fuel to increase power. Past stoich, you get dimishing returns on this until you hit the rich-best air:fuel limit of the fuel.
With alcohol, this just happens to be about twice gasoline (rich-best ratio at 6 instead of 12). Alcohol has other benefits, though, as mentioned above - detonation resistance, etc., that make it more desirable overall than gasoline in certain applications.
Now, on a diesel engine, where we have (for the sake of argument) unlimited potential oxygen available in the combustion chamber (via both boost and nitrous oxide), we are essentially fuel limited - as much fuel as you put (efficiently - reasonable injector on-time) into the engine, you can lean it out with air.
If we switched to alcohol, we'd have to run 248% more fuel to make the same power, but would require less oxygen to get the job done.
The point being is not to belive all the B.S. posted up on some websites. Anybody using the "they're running alcohol" line obviously has no clue how it works. If you want to see the fuel being used feel free to ask the race team.
Last edited:
if you say so. I would still love to see someone pump #2 in that car right of the pump just to make a believer outta me. There's no way I will ever believe that engine runs on #2 untill I see that.
you probably wont see that as Im sure it isnt a run of the mill pump diesel. But it is most likely diesel.
Building a diesel to run on alcohol takes a lot of parts that are not on this dragster.
However it is done more often than many people think and the power output is amazing. They can take a 3500hp 640 cu in pulling motor and switch to alcohol and make over 5,000. Thats what the Silver Bullet Pulling Tractor is making for power but it also uses nearly 30 gallons of fuel per minute.
To do this you need to make your own heads and ignition system, etc the list goes on.
Diesel to Alcohol conversions........DO REQUIRE conversion to spark ignition! Essntially they become super heavy duty "gassers". Now im not taking sides or holding hands or being payed or anything, but im not seein any spark ignition components on the Banks Dmaxes. Now exotic diesel fuels, i have no idea. If i could get my hands on "premium" or "race" diesel fuels, i'd sure as hell run it. But even at that, it is still just diesel fuel is it not? Besides diesel to alky conversions, alky into the main injected fuel stream, as per the above description of alcohol, seems plausable, your loosing HP. As a secondary injection, pre-combustion chamber, gains as lower IAT and additional fuel are had but i also dont see any secondary fuel injection. If they didnt fog the crap outta there diesels with nitrous, they would smoke like a freight train like the most of the rest of the hi-perf diesels and vice versa, our smokers would run like a bat outta hell and sqweaky clean with that much NO2. All i see is alot of diesel being oxidized and burned with alot of spray and clever simbiant tuning between the two. Any non disclosed fuel aboard to gain performance would be uncharitable and dirty (no implications!) but still dosnt take from the fact its a wicked fast D-max