Miatapower List Archive

This read-only message was archived from a public mail list.
Mail From: "Tom Graham" <(email redacted)>

Air is the insulator in the combustion chamber. The spark must jump the gap
between the plug electrodes and increasing the air density, from boost,
makes this harder. Does humidifying the air with water injection make the
spark plug gap easier to jump?

I have already found that running an excess rich mixture will run rough with
the addition of a significant WI. I was able to lean the mixture for a
significant increase in smooth power.


Tom Graham

This read-only message was archived from a public mail list.
Mail From: "Robbi Laurenson" <(email redacted)>

That would depend on the purity - very pure water will conduct poorly
whereas salts in the water will add to the conductivity. However I imagine
even store-bought distilled is conductive and will affect spark gap jump. I
have also seen warnings that too much water at low rpm can cause shorting of
the plugs which would support the conductivity theory.

My fuel map was quite rich, but I encountered no stumbling up to 200cc/min
water injection. I did lean out my fuel and got an improvement in power and
delivery, though.

How rich are you talking? How much water?

-----Original Message-----
From: Tom Graham [mailto:(email redacted)]=20
Sent: Sunday, April 06, 2003 6:34 AM
To: MiataPower
Subject: WI and Ignition Question

Air is the insulator in the combustion chamber. The spark must jump the gap
between the plug electrodes and increasing the air density, from boost,
makes this harder. Does humidifying the air with water injection make the
spark plug gap easier to jump?

I have already found that running an excess rich mixture will run rough with
the addition of a significant WI. I was able to lean the mixture for a
significant increase in smooth power.


Tom Graham

This read-only message was archived from a public mail list.
Mail From: "Tom Graham" <(email redacted)>

Hi Robbi,

I can't imagine much liquid water gets to the plug gap. I am thinking about
humidified air. In my case I'm not sure how much fuel I was running, too
much I suppose. I was just playing around with very light water injection
and I must have been very rich because when I increased the water my engine
ran rough. I reduced fuel allot and picked up smooth WOT running, quiet
exhaust and more acceleration. I could also have weak spark which would
perhaps show the same result by running smoother with mixtures not so rich.

I'm a set-of-the-pants tuner. Go richer, if faster keep going richer, if
slower go leaner. Keep this up until the sweet spot is hit. Start all over
when the sun comes out. I do the same with timing. More advance until the
engine feels right.

Tom

----- Original Message -----

That would depend on the purity - very pure water will conduct poorly
whereas salts in the water will add to the conductivity. However I imagine
even store-bought distilled is conductive and will affect spark gap jump. I
have also seen warnings that too much water at low rpm can cause shorting of
the plugs which would support the conductivity theory.

My fuel map was quite rich, but I encountered no stumbling up to 200cc/min
water injection. I did lean out my fuel and got an improvement in power and
delivery, though.

How rich are you talking? How much water?

-----Original Message-----
From: Tom Graham [mailto:(email redacted)]
Sent: Sunday, April 06, 2003 6:34 AM
To: MiataPower
Subject: WI and Ignition Question

Air is the insulator in the combustion chamber. The spark must jump the gap
between the plug electrodes and increasing the air density, from boost,
makes this harder. Does humidifying the air with water injection make the
spark plug gap easier to jump?

I have already found that running an excess rich mixture will run rough with
the addition of a significant WI. I was able to lean the mixture for a
significant increase in smooth power.


Tom Graham