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A very interesting application for water injection..........

Posted: Jan 01, 2007 7:18 PM
by Duke
Mixing nitromethane RC car fuel with water an injecting it.

One guy is claiming it works well with no issues. Reported as a 50+ hp addition to the arsenal.

Here is a link to the discussion.....its 10 pages long though -
Boosting with Nitromethane

"NITROMETHANE - usually used as a mixture with methanol to reduce peak flame temperatures - also provides excellent increases in volumetric efficiency of IC engines - in part because of the lower stoichiometric air-fuel ratio (1.7:1) and relatively high heats of vaporisation ( 0.56 MJ/kg ) result in dramatic cooling of the incoming charge. The nitromethane Specific Energy at stoichiometric ( heat of combustion divided by air-fuel ratio ) of 6.6, compared to 2.9 for iso-octane, indicates that the fuel energy delivered to the combustion chamber is 2.3 times that of iso-octane for the same mass of air. Coupled with the higher flame temperature ( 2400C ), and flame speed (0.5 m/s), it has been shown that a 50% blend in methanol will increase the power output by 45% over pure methanol, however knock also increased. "


Could be the answer to the breaking the 600 hp barrier.

And for you NA guys, another reason to think about W/A injection.

Oh yea........you will see that I jacked my Avatar from Turbo Jacky.

Posted: Jan 01, 2007 9:32 PM
by Skeen
however knock also increased

Posted: Jan 01, 2007 11:49 PM
by M635CSi
Skeen wrote:
however knock also increased
I believe Nitromethane effectively leans out the Air-Fuel mixture so tuning they system would be required...

Posted: Jan 02, 2007 2:03 AM
by Jeremy
Leans it out (nitromethane releases lot of oxygen when vaporized, kinda like nitrous) and lowers the overall octane of the mixture entering the chambers (nitromethane has an octane rating of like 36). The amount of leaning and reduction in octane will be dependant on the amount of nitomethane injected. Octane will be determined by the ratio of nitromethane to gasoline as well as the octane of that gasoline. Not sure if it's really enough to effect anything, but do you really want to lower the octane of your mixture, particularly given your knock issues?

Overall, it doesn't sound like a good idea for a motor you want to last any length of time. Not without very careful and precise tuning anyway.

Jeremy

Posted: Jan 02, 2007 10:31 AM
by Rich Euro M5
IMO, if you want to spend money to improve performance using fuel for models isn't the way to do it. What they aren't telling you is, there aren't many model fuels out there with 50% nitromethane. Typically you 'll find 15%, and up to 30% in helicopter blends. If you want anything higher you usually have to get it custom mixed. The other thing, model fuels are not just nitromethane and methanol, there are also antifoaming agents, rust imhibitors to deal with the nitric acid which is part of combustion, and the ever present 15% - 22% oil content. Finally don't forget price, regular 15% sport fuel costs about $12/gal, a 50% nitro blend will cost you at least $30/gallon.

You can buy toluene which is a proven octane booster to mix with your gas for a lot less $$$s.

Rich

Re: A very interesting application for water injection......

Posted: Jan 23, 2007 12:33 PM
by Nebraska_e28
Duke M535ti wrote:
Oh yea........you will see that I jacked my Avatar from Turbo Jacky.
And I was thinking you code html as a side job.. :rofl: