When you say 20% glow what do you mean by that 20% oil or 20% nitro? If you can get some nitromethane mix it at 3-5% with your 50/50 blend and your engine will run much much better and smoother: the other thing you can do is to mix your 20% nitro fuel at a 3:1 ratio with methanol and the mix it with your gasoline at 50/50 blend once mixed that should give around 2.5% nitromethane and about 2.25 to 2.5 % of oil content which means about a 40:1 oil ratio (75% methanol and 25% glow fuel = 3:1 ratio) you won't need to add oil to the mixture because the glow fuel is already providing that, usually glow fuel contains about 18-20% oil.
But I am glad to hear the results that other people like your self are getting, and to know that this experiment can lead us to a cheaper way to reduce weight in our engines and at the same time increase a little bit these engines performance without having to do a lot of modifications to the engine.
Lets keep this tread alive and interesting for the benefit of us modelers. I know that there are allot of skeptical people out there but didn't Columbus, Copernico and allot of other people or scientists face the same skepticism? so go for it.