16:1 to 18:1

[BassVirolla]

The engine regulations do not mention anything on the type on injectors that an be used.

The manufacturer can therefore use a compressed air assisted injector that could inject more air into the cylinder as it reaches TDC to increase the compressed air pressure from 77bar to 87bar by adding 2cc of compressed air.

Two posts above yours, it was stressed that high "compression" is not the goal. (The goal is high "expansion"). The current engines deliberately reduce the "compression" using Miller cycle valve timing. The 18:1 permitted CR is utilised in order to achieve a high expansion ratio.

There's some confusion in the facts that:

- More air (which tragically / inefficiently equates to more compression pressure) allows for more / better burning of fuel, which release more energy.
- More expansion allows for better conversion from heat to mechanical.

But no, more pressure / compression don't release more energy from such combustion.

So, I doubt we are researching ways to compress more, but:

- Options to shove more air in the cylinder.
- Options to expand more such air.

But a geometrical 18:1 allows for more expansion of a given mass of air than 16:1.

With a Miller cycle, more CR does not necessarily equate to more maximum in cylinder pressure. Even more, increase such pressure without increasing the expansion is (thermodinamically) a nonsense, but opens the possibility to burn more fuel less efficiently, which I doubt is the goal of this ruleset.

[AR3-GP]

The engine regulations do not mention anything on the type on injectors that an be used.

The manufacturer can therefore use an compressed air assisted injector that could inject more air into the cylinder as it reaches TDC to increase the compressed air pressure from 77bar to 87bar by adding 2cc of compressed air.

You can't inject air through the fuel injector. It's not allowed.