Higher Nitro Content

[Tuslow1]

I went from 20% to 40% and Miss Vegas Is acting weird, what is the posibles? I have been turning and turning to lean and richen it with the same results, NONE! and while it is running like a dog it is drinking this stuff like a old alcoholic. The way it is running is telling me it is too lean, but I'm scared to richen the mix any further... already at 1 3/4 turns out and it seems to be asking for more.... the fuel is O'Donnells 40%. What advice can you offer?

[mjmsprt40]

Welcome to the real world of fuel mixtures. Likely as not, you ARE running too lean. You're running more nitro, and nitro burns at a considerably faster rate than methanol does. Methanol runs (in our engines) at something like an 8 to 1 air-fuel mix, while nitro is more like 1 to 1 mix. The more nitro, the more you'll have to turn the needle out. Add a pipe like most of us do, and watch that puppy REALLY suck up the fuel.

[Tuslow1]

:eek: So my novice ear was correct in hearing it asking for more? LMAO hey this stuff aint cheap and if the 40% is going to just get guzzled away. The thought really scares me of buying 65%. With that all in mind my Nitro budget is looking better and better at 20%. Thanks MJM.. :wave:

[Chris LaPanse]

Yep, you need to richen it. Nitromethane burns at 1.72 parts air to one part fuel (roughly), while methanol runs right around 9 parts air to one part fuel. So, the more nitro, the less methanol, and the richer it needs to run.