Plenum fuel injection for reduced IATs?

[RCJ]

Acetone 132 boiling point
Toluene 231
Nitro propane 270
I have these 3 ,any suggestions
Low c/r, low hp, carb,made best power on 87 pump gas.has restricted intake per rules

[mk e]

while changing the fuel components will certainly change the evaporator cooling I don't think you can change the fuel without also changing the hp...so you'd have no way to know if it was the fuel, the cooling or how much of which they changed the hp. I don't think that test would get you the result you seek....you have to mess with the injection location and/or injector design, think.....

[Newold1]

My thought is the reason that injecting fuel in a plenum instead of an actual port in an EFI application is not going to increase the overall performance of an EFI engine is that on most plenums in EFI applications the air movements in the plenum tend to be confused and uneven. Putting fuel in this air would usually result in uneven air/fuel mixtures to the cylinders and hence the small gain that may occur thru plenum cooling would be lost with overall the uneven air/fuel mixture to individual cylinders. My thought on this comes from the building of quite a few EFI single throttle body plenum type manifolds where the air movements inside the dry plenum were tracked and observed inside the plenum with the engines on a dyno, Was always amazed that air does not always flow in directions, places or amounts you would think in a plenum. I think a better isolation of the intake from radiated heat of the engine thru special intake gasket material, isolation from engine coolant and isolation from lifter valley areas is a much better power adder.

[David Redszus]

Boiling point
Acetone ..........132F
Toluene ..........231F
Nitro propane...270F

Stoich
Acetone ............9.51
Toluene ...........13.46
Nitro propane......6.90

Heat of combustion BTU/lb air
Acetone ............1293
Toluene ............1299
Nitro propane......1292

None of the above will provide more power due to heat of combustion.
Acetone will eat every polymer in sight but has a low boiling point.
Toluene will raise octane, a moderately high boiling point and only moderate power.
Nitropropane is junk and should never be used.

The best additive to lower boiling point and raise vapor pressure is called isopentane. Use about 20%.

[jmarkaudio]

Or change fuels. VP C-25 has an overall low boiling point, if you can use an oxygenated fuel try Q16. Q16 needs a bit more fuel added...