Sandro

iTrader: (1)

Any negatives?

For the time being, my goal is to use WI to lower air charge temperature.

My thought is that water injected before the IC would:

- mix at the hottest point along the path and have more time to evaporate
- perhaps [and for what is worth with a stock IC] increase the efficiency of the IC [I still have to research on the influence of moisture on heat transfer coefficient]

I have been reading that some of you don't use IC at all, so I guess this should work but would appreciate getting your specific opinions. By the way, I would love getting rid of the IC completely if possible, less weight, more room for the radiator to breath, lower pressure drop and much quicker throttle response.

Application is autox, have stock twins and cannot use methanol or alcohols.

Thanks.

- Sandro

fendamonky

iTrader: (6)

The main problem with spraying before the intercooler is that, eventually, you could fill it up. The idea is to have as much mixture atomize as possible before hitting the engine. As I understand it the process of atomization is what lowers your intake temp, you want a clear track for this to happen in. I'd be worry about having the water spray come to a halt as soon as it hits the IC, prohibiting a proper mixture, and filling the Intercooler with water.

If I were you I would mount the nozzle just after the Intercooler in the connecting pipe between the IC and the Elbow (this is where mine is located). That will give you a clear shot to the intakes, with nothing in the way, while maintaining enough distance to promote full atomization.

Just my $.02..

And how will the Autox guys know if you mix a little Meth into your distilled water??? Theoretically, if they will place a restriction on that, you should still have your main cat in. In which case you *shouldn't* really be spitting flames anyway..

Sandro

iTrader: (1)

Thanks Levi, good point.

I also spoke with a friend who worked in the past on WI for diesel engines and he actually raised other puzzling side effects:

1. When water becomes steam, volume increases by three order of magnitude. If vaporization occurs before entering the combustion chamber it causes oxygen dilution, which reduces the amount of oxygen available for combustion (at a given VE efficiency)
2. Another problem associated to such large variation in specific volume is that if nozzle is placed before the IC and then condenses back to water in the IC, it may create large pressure waves which could interfere with the compressor operation
3. In the applications my friend is familiar with, water is injected directly into the cylinders after the intake valves close, and the oxygen is "trapped" already inside the combustion chamber; besides reduction in combustion temperature, steam expansion also contributes significantly to push the pistons down and augment power.

I am wondering now, what would this mean for our rotaries? By injecting water in the UIM, even assuming that no significant vaporization take places to displace oxygen, what happen when water vaporizes inside the rotary chamber? Without controlled direct injection, couldn't uncontrolled expansion start "pushing" against the rotor before ignition take place? Wouldn't this cause an additional load for the engine to overcome rather than additional motive power?

Thanks,

- Sandro