Hey does anybody know anything about Water Injection systems. I hear it a new thing that constantly sprays very small amounts of water into the engine, the water instantly vaporizes and cools the engine. Is this correct? Does such a system exist? Anybody know anything more? Thanks in advance...:thumbup:

 

Actually, it is a very old technique, pioneered on WWII fighters to give them extended altitude and power for short periods of time.

I'm relatively experienced with it, and have been very impressed with the results, especially considering how inexpensive a system can be.

It is most commonly used on turbocharged cars, but I'll be trying it out on an NA application soon enough.

 

It works by helping to better atomize the fuel for combustion, while increasing cylinder pressures during combustion without promoting un-even burn and detonation the same way high static compression can.

 

and in the process it significantly raises the detonation point of the fuel, no? That's what I understood it as; water helps atomize the fuel, burn it more evenly, and cool down the cylinder temperature, allowing much higher compression ratios with much better reliability.

If this is true, then with a water injection system, would something like 12:1 be achievable on 91 octane fuel in a daily driver? thanks

 

Water injection is best used on a need basis [such as under high load, extreme timing advance, or during boost], to use such a system on a high compression engine isn't very feasible because of the frequency that you'd have to replenish ANY size water tank you use. Sure, a 5 gallon tank in your trunk would do the job, but you'd offset the power/reliability gain with added weight.

 

Yeah thats what i was hearing...cooling, and compression aspects gaining potential. I was pretty sure about the fact that it was usually used on boosted cars. My friend has a MR2 with a T20 turbo and was thinking about purchasing a system... and yeah they are relatively low in price for the gains you get... thanks again everybody.

 

On my brother's Eclipse he's got two nozzles, one pre intercooler and one pre throttle body. The first nozzle comes on at 5 pounds of boost, the second at 10 pounds. We've seen temp drops over 100 degrees at his throttle body. (Granted, his temps are pretty hot due to how hard we're running a relatively small turbo) This has allowed him to run his turbo at its efficiency limits while retaining full timing advance all the way out to 25 pounds of boost on pump gas.

He went from gobs of knock and losing over 10 degrees of timing to a flat knock datalog.