Cool title, eh?

Anyhow, I was "designing" a nitrous system in my head and I was thinking about the fairly common wet system practice of using a seperate fuel tank for the "on" fuel.

I blend my own race gas with ordinary pump gas and Toluene in a 4:1 ratio. With 4 gallons of 93 octane pump gas and one gallon of 114 octane Toluene I get an octane of 97.2, which is more than enough for most high performance street engines. If I happen to use 92 octane oump gas I get 96.4 octane. So basically, we're talking about 97 octane "tank" gas.

Before anyone expresses concerns about using Toluene, keep in mind that it's a pure hydrocarbon, is already a major additive in the gas everyone buys at the pump, and was well well researched and in use long before I found out about it. It's safe for OX sensors and Cat converters as well. You could even use straight Toluene in your gas tank if you wanted to, provided you had a high enough compression or a strong ignition system.

So, back to the question:
If I turn around and use straight Toluene in the nitrous system's fuel cell, that makes for an Octane Differential of 17! Most folks who do this, at least as far as I know; use a 100 to 106 octane fuel for the supplemental, on top of a mid-90's octane blend of pump gas and race fuel, for a differential of roughly 5 - 10 octane.

Here's my concern...
If you have two different fuels in the combustion chamber, with such dramatically different octanes (17 octane differential), and thus burn rates; how will that behave?

 

Good question. Depends how much they blend together.

How much are you spraying? Sounds like someone is addicted to Octane numbers

 

I'm not spraying anything yet, although I'm planning on a 200hp progressive setup.

As to the octane numbers; I've discovered over the years that the more I can work out before buying parts, the cheaper things tend to be.

 

A friend and I both just switched back from seperate fuel systems to just plain running race gas in the tank.

There are some advantages to running a seperate fuel system but you can search those. I'm supportive.

Probably the biggest problem with what you're contemplating is the mixing of not just pump gas and race gas but then throwing toluene into the mix. Goodness only knows the final octane. That'll be like trying to tune a gorrilla, as Musi puts it.

Start slow: spray conservatively, leave the stock retard program intack, and read those plugs. Engine parts are expensive, just run the 200 with 112 and get ready for some seriously low ets.

 

I would have say that the higher octane would burn slower.. Thus the 93 stuff would gets things rolling and help the higher octane start burning sooner.
Ricky