Direct port injection

[Forum Admin]

I don't disagree that the set up would not be ideal for wet flow especially for something that needs to as finely metered for instance as fuel. The "water" will be atomized and also is only about 2% of the air/water induction charge prior to the fuel injectors.

Also generally the total concentration of water being injected is more than absolutely necessary for knock suppression. Something like 5% water to fuel is enough to replace the fuel previously used for cooling when leaning from 10:1 to 12.5:1 AFR. So with a 15% target water to fuel flow if a cylinder gets 10% and another gets 20% it should not be harmful. I would not expect that much variability between cylinders though - this is just an example.

Certainly the EGT by cylinder test you propose would identify how much variability there is.

The more concerned you are about mixtures the further down the induction path you should try to inject.

There is a tuner in England testing WI EGTs on 4 cylinders currently with a dry manifold but the runners are long and I expect the mix will be OK.

The other problem with multi port injection is that the amount you are trying to flow is very low on a per cylinder basis - even with a 0.4 mm jet you will be getting into IDCs where you will have lean induction cycles. I think without a very complex and well managed system you may have more rich/lean water conditions than a single jet through a dry manifold.