[mrx79]

Hi,
just want to give some more updates. After doing some calculations of my WM flow:

until now 350ccm Nozzle: W/F:60%@4000rpm -> 22%@8000rpm
new 140cc Nozzle: W/F:24%@4000rpm -> 9%@8000rpm

i decided to switch to a 140cc Nozzle.
Also switched from 100% Water (frist tests with the 350cc nozzle) to a WM50% by mass mixture.

Results so far (with tune basicaly untuched: AFR=0,8-0,85 / Advance: ~21-22?BTDC @ 16psi)
i experience a similar power loss with the 140cc nozzle as from the 350cc nozzle against the non-WI baseline run.

I then did some calculations on vapour pressure of water&methanol and checked this against my compressor efficiancy. This showes that my compressor is very effective and to keep the water/meth in steam form if once evaporated i have to run at least 18-19psi of boost to keep up the temperature with the rairing pressure after the turbo.
This also not includes the temperature drop from the evaporation.

My calculations showed a too much amount of WM with the 350cc nozzle, so the power loss could be explained, but with the 140cc nozzle i'am in a good ballpark i guess and i'am also below 100% satuation so theoreticaly all the WM can evaporate if enough heat is present.

With this results i'am currently thinking if my setup is just too efficiant for pre-compressor injection - can that be the case?

That something is happening when activating WM is for sure, but what causes the power loss?!

When i assume (just a guess) that most of the WM get's into the combustion chamber unevaporated it will evaporate there under the huge pressure and temps and reduces temps there by a "huge" amount.

Methanol burn slower then gasoline. Water cools the combustion chamber. This would lead to the suggestion that i need more timing. But in fact, i'am still very uncompfortable with even higher amounts of timing.

But this maybe can be a hint that at my current power levels, i just don't need WM injection?!?
By the way, i have to add: i'am running 98roz fuel and the basic compression ratio of my engine is 8.5:1, so fairly low.