[60man]

Originally Posted by Tom Vaught

the National Advisory Committee for Aeronautics, in studies aimed at increasing the power from aircraft piston engines, came to the following conclusion: “The data indicated that water was a very effective internal coolant, permitting large increases in engine power as limited by either knock or by cylinder temperatures.”

Engine power production, referred to as brake mean effective pressure (BMEP), is measured by taking the average effective pressure of the cylinders as they progress through intake, compression, ignition, and exhaust strokes. Added power comes as a result of greater pressure, but a higher temperature inside the cylinder accompanies greater pressure. These higher temperatures can lead to detonation, referred to as engine knock, or pre-ignition, both of which are cases where the fuel-air mixture burns in an undesirable manner and can be destructive to an engine. To combat knock and pre-ignition as power increases, a richer air-to-fuel ratio is normally required. If the addition of extra fuel doesn’t provide enough knock protection, then a higher-octane fuel, which is more resistant to knock and pre-ignition, may be used. However, once the knock limit of a higher-octane fuel is reached, can anything be done? This is where a water injection system presents an appealing option.

The issue may be that cooling the charge may not be enough vs the higher octane fuel.

Tom Vaught

Originally Posted by T Syron

From VP race fuel website.


NEW! C85™
If you’re committed to using E85 type fuels, C85 is by far your best choice. Conventional E85 fuels are notoriously inconsistent, requiring up to a two-jet swing in tuning from one batch of E85 to the next. By contrast, C85 is blended with a consistent proportion of ethanol and every other component in every drum. In addition to taking all the guesswork out of tuning, C85 makes up to 4% more power and torque than conventional E85. With higher quality pure components, C85 is superior to E85 in terms of cooling effect, resistance to detonation and even includes corrosion inhibitors to fight the issues presented by ethanol. C85 works well in drag racing, oval track, off road and virtually any other automotive application, in particular forced induction applications due to its lower vapor pressure. Tests of C85 indicate most applications will require richening up by 1 jet size, or 2-3% over current jetting. Note that for racers unwilling to invest in the new carb and expensive fuel system upgrade required for E85, VP’s MS109, VP113 and Q16 continue to be the best race gas alternatives for the money.


Tom Syron

Can't stop this quote ????