David in Australia with Renault Scenic

[cRiPpLe_rOoStEr]

Originally Posted by ar5boosted

I put it on a Suzuki but then I had some tuning issues - best described as a fail on my part. I never was able to duplicate the economy improvements on the EFI engine due to lowered engine temperatures. I injected too much cold water and blew the Head-Gasket. My enthusiasm declined after that although I do have reflections on how I could have done better.

The colder air stream and the higher concentration of oxygen might have fooled the ECU to enrich the mixture instead of leaning it. Maybe if you got it injected after the MAP and temperature sensors, it could have increased the fuel economy in a similar level to what you hve experienced with the carburettor-fed Mitsubishi van.

[ar5boosted]

Originally Posted by cRiPpLe_rOoStEr

Maybe if you got it injected after the MAP and temperature sensors, it could have increased the fuel economy in a similar level to what you hve experienced with the carburettor-fed Mitsubishi van.

I could feel the familiar feeling of the extra torque of the water going in.

It was just disappointing when I didn't get a big improvement in fuel economy from the water-injection and then sometime later the car got crashed. I discovered that pre-heating the water made a big difference. Water viscosity is very important. I got the car from around 400km/tank to 650km/tank (40l) so I was somewhat happy but nothing that would really impress anyone on this forum much.

If there was an open source fuel-economy ECU project that anyone knew of I'd be interested in hearing about it. I think I'm getting ready for a fuel-injector remap computer because I suspect that there are a few deficiencies with the logic in most ECU's especially in relationship to thermal management.

I'm setting about to rear-mount turbo-charge this car. We'll see what happens then.

[cRiPpLe_rOoStEr]

Originally Posted by ar5boosted

I discovered that pre-heating the water made a big difference. Water viscosity is very important.

Interesting. It's more usual to see claims that a colder water would lead to higher improvements, even though a higher temperature would lead to an easier vaporising of the gasoline and decrease pumping losses due to a slight decrease on the dynamic compression.

I got the car from around 400km/tank to 650km/tank (40l) so I was somewhat happy but nothing that would really impress anyone on this forum much.

How would you say that 62.5% improvement wouldn't impress anyone?

If there was an open source fuel-economy ECU project that anyone knew of I'd be interested in hearing about it. I think I'm getting ready for a fuel-injector remap computer because I suspect that there are a few deficiencies with the logic in most ECU's especially in relationship to thermal management.

Have you never heard about those programmable ECUs such as FuelTech? Even though they're more focused on performance applications, there are some folks doing some interesting efficiency-oriented projects with them.

I'm setting about to rear-mount turbo-charge this car. We'll see what happens then.

The only downside with a rear-mounted turbo is the increase on turbo-lag, but it doesn't seem totally bad since it allows the compressed air charge to decrease its temperature naturally a little before it reaches the intake manifold, mostly avoiding the need for an intercooler.

[ar5boosted]

Originally Posted by cRiPpLe_rOoStEr

Interesting. It's more usual to see claims that a colder water would lead to higher improvements, even though a higher temperature would lead to an easier vaporising of the gasoline and decrease pumping losses due to a slight decrease on the dynamic compression.
.

True.

My take on this is that the colder the water the more heat that it will need to absorb.

The downside of colder water is that it is 'harder' or denser. So I'm convinced that it led to blowing a head-gasket. Probably because there was too much water going in one particular cylinder. Sometimes what goes on in an engine is mysterious.

Originally Posted by cRiPpLe_rOoStEr

How would you say that 62.5% improvement wouldn't impress anyone?

I guess so.

Originally Posted by cRiPpLe_rOoStEr

The only downside with a rear-mounted turbo is the increase on turbo-lag, but it doesn't seem totally bad since it allows the compressed air charge to decrease its temperature naturally a little before it reaches the intake manifold, mostly avoiding the need for an intercooler.

Hope so.

Picture: (Garrett was installed this week)

[cRiPpLe_rOoStEr]

Originally Posted by ar5boosted

My take on this is that the colder the water the more heat that it will need to absorb.

The downside of colder water is that it is 'harder' or denser. So I'm convinced that it led to blowing a head-gasket. Probably because there was too much water going in one particular cylinder. Sometimes what goes on in an engine is mysterious.

Then it would be better to just use a smaller amount of water, or to blend it with a small amount of ethanol to make it evaporate easier, and also the spraying pattern is important. Thinner droplets would increase the surface area in contact with the air in order to absorb heat and evaporate more effectively. Anyway, it doesn't sound so likely that a bigger amount of water in one particular cylinder would lead to a blown head gasket.