Warm Air Intake With Steam

[jakobnev]

Now how to fool the MAF?

Inject the steam after the MAF but before the throttle body.

[t vago]

Originally Posted by teoman

AMount of steam = amount of water i inject.

I have an gasoline injector where i can control the pulses, so i can precisely measure the water entry to the system.

You're going to use a fuel injector to inject the water?

You're going to want to ensure that the injector came off a car that is capable of running E85, or at the very least has stainless steel innards. You're going to also want to ensure that your water contains a small amount of cutting oil or something similar, so the injector innards are kept lubricated.

[teoman]

That is exactly my intention. That way i can control the precise amount of water/steam injection.

Thanks, i will do those. However injectors are cheap (free for me, i get them second hand from a tuning shop that does upgrades). Harlan (forum member) is running straight water through his and no problems so far. It needs the occasional cleaning with vinegar.

I plan on running distilled water through mine.

[teoman]

Another wuestion. Stainles steel or copper pipe.


Also should i wrap the exhaust to keep tje catalytic happy?


I am still pondering how the ecu will know to cut back on the fuel.

[teoman]

I wonder also if i can really wrap a lot of copper pipe around the exhaust manifold so that i can inject less steam at high temperature.

I also intend on using 0.5 mm ID 1.5mm OD silicone tubing to transfer the steam. The restriction will increase slightly the pressure of the system and provide fast flow on the output enabling proper mixing.


I still have to look at the delay of the system an maybe implement a smith predictor or such algorithm.

[teoman]

I am also using lpg, which already has a high octane rating.

[t vago]

Originally Posted by teoman

I am still pondering how the ecu will know to cut back on the fuel.

A properly designed system will cause the engine to do less work.

Less work directly translates into less air demand. (Load, if you will)

The engine's MAF will see this lessened air demand, and will cause less fuel to be injected as a result.

[teoman]

Hnm.

I suppose that the vapor takes up some volume. In our calculations we assumed that the vapor dumps its energy to the air transforming in to water droplets.

But the hot air will then take up %20 more volume, so less air will be drawn to the engine and the maf will sense that and inject %20 less fuel (hopefully).

[teoman]

http://qspace.qu.edu.qa/bitstream/ha...pdf;sequence=3

The tables towards the end are very interesting.

They study the intake air temp (initial temp) vs AFR vs burn speed.

The speed change caused by the water droplets remains still an unknown.

I am guessing that i should try to make combustion speed my match gasoline at 30 degs C ??

[teoman]

From those tables it seems that increasing the air temp to 80 degs just like in our example increases combustion speed %32. The burn speed of a lean mixture (0.8) at 80 degs comes close to stochiometric mixture at 20 degs. Still not sure how the presence of water will impact this.