BTU #'s?

[87GNcospg]

what exactly does the BTU number of different forms of alcohol mean? methanol seems to have the lowest number. this means that methanol has the lowest amount of enrgy to give up when it is burned? why is it the best for use in RAZORs kit, race cars, and other things?

im just confused. a low BTU # benefits our cars because...........?
gasoline 109,000 - 125,000 Btu
ethanol ~80,000 Btu
methanol 56,000 - 66,000 Btu

 

[TurboTR]

Yes that is a downside when considered as a fuel. But the upside in this example is, stoich a/f ratio for alcohol is nearly half that of gasoline. So you also burn nearly twice as much for a given amount of air consumed. Which also implies that you have to vaporize nearly twice as much, which is where the big cooling effect comes from, vaporizing alot of liquid

TurboTR

 

[DavzGN]

The cooling effect is caused by the amount of energy needed to convert the alcohol from liquid to vapor. Because more methanol is needed for a stoich ratio you get more total cooling. There was a post a while back discussing the energy needed to convert the various types of alcohol to vapor, but I don't recall the details, but I seem to recall that methanol had one of the higher energy requirements.

David
87GN

 

[Swede2]

Methanol uses less air than gasolin does. So that means your turbo is more effective because it dont need to use the same amount of air as when on gasoline.

If you compare Ethanol and gas, you have to run about 30-50 % more ethanol to get to the same power level as you are on gas.

Daniel

 

[87GNcospg]

Originally posted by Swede2
Methanol uses less air than gasolin does. So that means your turbo is more effective because it dont need to use the same amount of air as when on gasoline.

If you compare Ethanol and gas, you have to run about 30-50 % more ethanol to get to the same power level as you are on gas.

Daniel

so if i have to sue more ethanol to get the same power level as gas. i would also need to run double the amount of methanol to be equal to gas.

 

[Swede2]

Yes, ethanol has more energy than methanol, so it would take even more methanol to run the same power level as gas. But again, you might be able to compensate that with higher boost due to the methanol cooling effect.

Methanol is very very corroding, and our fuel lines dont support it. So you would probably have to change the gas tank, and all lines and also the injectors.

A top fuel drag racer can answer that better than me.

Daniel

 

[87GNcospg]

gasoline has double the power levels of methanol. why exactly do F1 cars and top fuel dragsters use M100 if it is not as "powerful" as gasoline? is it primarily because it forces more air to be burned and the cooling effect of all that alcohol? am i missing anything else?


i wish a chemistry person would chime in. lol. maybe i should go to a different forum.

 

[Swede2]

As you surely know have methanol the highest octan available of all chemicals out there. Thats why the dragsters use it I suppose.

Your wrong on the air thing... Methanol uses lesser air to burn. It takes more heat from the air and thats why everything gets cooler...

Well, I am not a chemistry... I shall stop here before I just talk **** lol

Daniel

 

[87GNcospg]

Originally posted by Swede2
As you surely know have methanol the highest octan available of all chemicals out there. Thats why the dragsters use it I suppose.

Your wrong on the air thing... Methanol uses lesser air to burn. It takes more heat from the air and thats why everything gets cooler...

Well, I am not a chemistry... I shall stop here before I just talk **** lol

Daniel

no. methanol actaully has more oxygen. the reason gas pumps add alcohol ,like MTBE, into the mix is because it adds more oxygen into the gasoline which causes a reduction in carbon monoxide. so you get mre air from the fuel and the turbo.