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Water Injection


mikeyd

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 Curious if anyone has a water - water/alcohol injection setup. Have always seen them available bet never saw one in action. Water only or 50/50 alcohol mix? Very pricey for the setup.

I know nitrous guys are big with them, any advantage over timing retard? Can you keep more timing and spray the water for more power?

Pictures are very welcome!

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Funny - i've never heard of their popularity with NOS guys. Turbo yes - known for its intercooling effect on the air temp but in a NOS motor by the time the temps are excessive the water would have been well gone. Rolls Royce used it to good effect with the supercharged Merlin engine - but that had intercooling and 130 octane fuel - all the tricks, water was the top up extra! Personally I believe it's a bit of a band-aid as it a) takes up volume that could be fuel and b) it doesn't burn so is taking up space........but that's just me I guess LOL!

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 …...bit of a band-aid  indeed and takes up some realestate !  here is a simple kit I set-up several years ago on a drawthrough gsxr…...high pressure pump , nozzle and 1 way valve , adjustable hobbs switch and relay , water/meth tank underseat and pump under battery box ( which was relocated to the swingarm ) ……. worked great for what it's worth  but still toasted some pistons just the same  .  

1307_turbo_build_004.jpg

turbo_1307_pics_005.jpg

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Water injection reduces intake air temp and increases knock resistance. So on boosted engine you will get more air in at the same boost and you can use more boost and ignition timing. So yes, you can make more power safely with it, on boosted engine.

Naturally there are downsides as well. The stuff takes space and weights something too. But if you compare to an intercooler it's probably easier to find place for a tank and pump. Then you need to take care that you don't run out of the water. And one factor that many seem to overlook is adjusting the amount of water correctly. If you inject too much you may get lower intake temp but still less power. And naturally too little doesn't give good effect.

I have seen all kind mixtures to be used. Water with methanol or ethanol, ratios anything between 0-100%. Plain water doesn't affect on fueling so you don't need to rejet or tune for it. Alcohol is fuel so more you inject it richer the engine gets. Apparently 50/50 mixture with methanol is prety optimal for maximum cooling and knock resistance. Personally I use 20% ethanol mixture since I don't want tooo much change for fueling and don't want to mess with poisonous methanol.

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Actually if you read the back to back tests of straight water v's %'s of water / alcohol, straight water wins out allowing more boost with less retard required. You'd think adding the alcohol would add power but I guess its evaporation point is so much lower that it adds a degree of cooling then just becomes a gas offering no further benefit?  What I'd like to try is a water / alcohol mist system over the front of an intercooler - that should really drag heat out of the system, but needs to be moving! - virtually pointless on a dyno without 100+mph air fans LOL!

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Just now, Gixer1460 said:

Actually if you read the back to back tests of straight water v's %'s of water / alcohol, straight water wins out allowing more boost with less retard required. You'd think adding the alcohol would add power but I guess its evaporation point is so much lower that it adds a degree of cooling then just becomes a gas offering no further benefit?  What I'd like to try is a water / alcohol mist system over the front of an intercooler - that should really drag heat out of the system, but needs to be moving! - virtually pointless on a dyno without 100+mph air fans LOL!

The Car boys mist Nos over the intercooler but its banned at drag race-meets for obvious reasons 9_9

 

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16 minutes ago, Gixer1460 said:

That's about as lame an excuse as a child could have dreamed up! Force them to fit a diaper then - no more problem!

Yes I agree but I don't write the rules ..."I understand its in the bike regs as well for SSB"

And that is what the guy with the mental 7 sec Evo did at Avon Park ...:v

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  • 4 weeks later...

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