water injection & AFC

[idt512]

how much fuel did you pull out after installing water injection, im getting ready to start tuning /logging tomorrow but id like to get a general idea as to how much richer it will be when spraying the water. Im using an M4 nozzle @ 75psi roughly and im on stock 450cc injectors running a 14B @ 17psi... if all goes well id like to get it to 20psi on 91 octane in the summer heat

 

[GVR4592]

It won't get richer if you're just injecting water. I wouldn't pull any fuel, because as soon as you run out of water you'll be in trouble. If you're fuel system is up to it, just increase the boost level and don't pull any fuel, and keep an eye on knock.

 

[ICE_T]

do you still running the smic??

 

[idt512]

GVR4592 - what do you mean by running out of water? ill be sure to have my container full before i begin my runs. Ive read from other posts that the A/F mixture runs richer when spraying... now im confused


ICE T - im running a Johnny racecar fmic

 

[GVR4592]

I meant just what I said, if you tune for water injection and you run out of water you will be screwed.

So what I would do is tune with the water injection off to the point where you can't get any more boost out of it without knocking. Then turn the water injection on and raise the boost level while watching for knock and IDC. Water will not make the mixture richer, it can allow you to run a leaner mixture without knocking. But without some active controls, that's not a good idea.