[juiced]

From what i've been reading 5.1:1 AF is what is required for a blown alcohol application.

In your experiance what is a safe AF for a car being run entirely on methanol for the fuel?

[Rocket468]

Just to give you an idea of a/f rations with differnt fuels.
I usually aim for 11.50 on gas which is pretty much 5.0 with methanol.

Note that Lambda is a ratio of ratios and is 1.0 exactly at the stoichiometric point for any given fuel. This table shows the approximate AFRs for a number different common fuels.

As fuel compositions are seasonal and regional, the AFRs shown here should be considered only as approximate.

The free-air Vout point of 4.00 volts is interesting from a number of viewpoints. The free-air voltage will vary a little from location to location as there will be differing trace concentrations of various hydrocarbon fuels in the atmosphere.

As noted above, the basic WB unit's Vout may vary slightly from the specifications shown here. The stoichiometric Vout of 2.50 may be a little higher or lower (+/- 0.03 Volts) and the free-air Vout may be a little higher or lower than 4.00. It's worth noting that the most important calibration value is to get the difference between the stoic Vout (2.50) and free-air (4.00) to be as close as possible to 1.50 Volts so that the interesting tuning AFR range (AFRs of between 10 and 15 for petrol) are then most accurately represented. When this 1.50 volt specification is achieved, and the unit's offset from the nominal 2.50 volt stoic value is compensated for, quite reliable AFR values can be obtained from the unit.

Vout Lambda Petrol LPG Methanol Diesel
1.40 0.686 10.08 10.63 4.39 9.94
1.45 0.696 10.23 10.79 4.45 10.09
1.50 0.706 10.38 10.94 4.52 10.24
1.55 0.716 10.53 11.10 4.58 10.39
1.60 0.727 10.69 11.27 4.65 10.54
1.65 0.739 10.86 11.45 4.73 10.71
1.70 0.750 11.03 11.63 4.80 10.88
1.75 0.762 11.20 11.81 4.88 11.05
1.80 0.774 11.38 12.00 4.95 11.23
1.85 0.787 11.57 12.20 5.04 11.41
1.90 0.800 11.76 12.40 5.12 11.60
1.95 0.814 11.96 12.61 5.21 11.80
2.00 0.828 12.17 12.83 5.30 12.00
2.05 0.842 12.38 13.05 5.39 12.21
2.10 0.857 12.60 13.29 5.49 12.43
2.15 0.873 12.83 13.53 5.59 12.66
2.20 0.889 13.07 13.78 5.69 12.89
2.25 0.905 13.31 14.03 5.79 13.13
2.30 0.923 13.57 14.31 5.91 13.39
2.35 0.941 13.84 14.59 6.03 13.65
2.40 0.960 14.11 14.88 6.14 13.92
2.45 0.980 14.40 15.18 6.27 14.20
2.50 1.000 14.70 15.50 6.40 14.50
2.55 1.037 15.25 16.08 6.64 15.04
2.60 1.078 15.84 16.70 6.90 15.62
2.65 1.121 16.48 17.38 7.17 16.26
2.70 1.169 17.18 18.11 7.48 16.95
2.75 1.220 17.93 18.91 7.81 17.69
2.80 1.276 18.76 19.78 8.17 18.50
2.85 1.337 19.66 20.73 8.56 19.39
2.90 1.405 20.66 21.78 8.99 20.38
. . .
4.00 free-air (can be used for calibration)

[juiced]

lol....

My 160lb injectors can't even flow enough at 90psi fuel pressure to hit that mark.

I guess i have to bust out the bigboys.... 212lb monsters

[cuchiracing]

Hi, I need some help, If I'm using alcohol fuel for the engine and 110 octane racing fuel for the nitrous system which A/F ratio do I need . This is a 2jz 1997 engine, Thanks .FRANK

[cuchiracing]

Hi, need some help, If I'm using alcohol fuel for the engine and 110 octane fuel for the nitrous system , which A/F ratio do I need when I'm using the nitrous system.

[Racer704]

I hope he gets this as it a year old so its a late answer.Tune it to the engine fuel which is in your case alcohol but not sure what your using but I would think its Methanol but you dont want to only tune from the AFR always and i will say again always tune from the plugs and use the AFR as a referance only. I wouldnt try to tune it to a optimum leval as you should have a small saftey cushion.That last little will not be worth the problems that could happen.

Have you tried to use unleaded 87 instead of 110 race gas?What this could do for you is give you is a hotter flash and more of a complete burn in the combustion chamber and it could even drop the EGTs by burning more of the fuel that may be going out the exhaust as unburned fuel. This in turn will make more power and use less fuel.