A Valiant BJ / Powerdyne BD-11

Bill Dedman said
I am not running fuel injection, but rather, a blow-thru modified Holley 750 double pumper. My question is this: The air/fuel ratio is made richer by adding pure methonol with a spray unit to the incoming air stream, but how is that mixture affected (on an A/F ratio broadband O2 sensor) when it's a mixture of water and methanol?

The methanol is fuel. It will show up on the mix as added fuel Water cools things off, but it has no fuel or oxygen available. It becomes steam. It is in fact just taking up space. A large dose of water is like turning on the EGR, just adding something that won't burn.

Is it still going to show richer, or will the water act a combustion deterrent for the meth, and not change the exhaust gas A/F ratio?

The fuel will all burn, and the steam will leave in the exhaust. The O2 sensor will "see" all of the fuel & air, while ignoring the water vapor.

I have a F.A.S.T. broadband datalogging O2 sensor meter, but have not hooked it up yet, and was wondering what to look for in terms of the spray's effect on the A//F numbers, with or without water in the spray (50/50 mix.)

Any help here would be appreciated!O:)

Nice meter. You can run straight methanol or 50/50 with water. It will tell you the truth either way.

B.