With falling octane ratings is water injection the obvious solution?

I had never heard of water injection until i read about an SE-R using an aquamist system and doing quite well with it. I mean if it works like it says I don't see why don't more people don't use it. Anyone know any downsides of it? So far the only articles i've read on it are from SCC and www.aquamist.co.uk After reading the SCC article i had the impression that we could pump 87 octane and run our cars like it had race fuel.

Just curious, but wouldnt you run outta water preatty quick? :) I mean i think it would be for like 1/4 time kinda deals.

I'd think so too but the pictures i saw of cars using them were road racing cars, not drag cars....oh yeah and who else read "water injection" and wondered at first, "what?! water in the engine??? on purpose?!"

When you add a little water to the mixture, it makes the intake air more dense, therefore providing more power...i dont know how long they have been doing it on cars, but on some jet engines they were doing it in the 60's-70's to provide more augmentation on takeoff. Cool :)

Originally posted by A380Driver
When you add a little water to the mixture, it makes the intake air more dense, therefore providing more power...

This is wrong. Water does not add more power, it makes less.

Using water injection in a normally aspirated car is a waste because it will make less power. The water displaces air and fuel and reduces power output.

The reason it works so well on a turbocharged car is they can add more boost and other tuning tricks to get more power than is lost. In a turbocharged car, the temperature of the mixture entering the engine is critical since it heavily affects detonation. All cars hate detonation, but especially turbocharged cars. The water injection lowers the intake temps and this allows you to run more boost and/or ignition timing.

The bottom line is, it will make a NA car make less power, but it can make a turbocharged car make more power because you and do things with a turbocharged car to more than make up for water. Remember, with NA, the water displaces fuel and air, but with a turbo, you just raise the boost and you can keep packing in more fuel and air.

Originally posted by P10DET


This is wrong. Water does not add more power, it makes less.

Using water injection in a normally aspirated car is a waste because it will make less power. The water displaces air and fuel and reduces power output.

The reason it works so well on a turbocharged car is they can add more boost and other tuning tricks to get more power than is lost. In a turbocharged car, the temperature of the mixture entering the engine is critical since it heavily affects detonation. All cars hate detonation, but especially turbocharged cars. The water injection lowers the intake temps and this allows you to run more boost and/or ignition timing.

The bottom line is, it will make a NA car make less power, but it can make a turbocharged car make more power because you and do things with a turbocharged car to more than make up for water. Remember, with NA, the water displaces fuel and air, but with a turbo, you just raise the boost and you can keep packing in more fuel and air.

so does this mean your running water injection? it can be used to anti-detonate your car if its overheating?

Originally posted by P10DET

The bottom line is, it will make a NA car make less power, but it can make a turbocharged car make more power because you and do things with a turbocharged car to more than make up for water. Remember, with NA, the water displaces fuel and air, but with a turbo, you just raise the boost and you can keep packing in more fuel and air.

Ahh ok cool! :) I guess I was thinkin about turbine engines and it applied to NA as well...

So where IS the water injected then on a turbo?

Originally posted by A380Driver


Ahh ok cool! :) I guess I was thinkin about turbine engines and it applied to NA as well...

So where IS the water injected then on a turbo?

its injected directly into the intake tube IIRC.