Water or Water/Methanol Injection DIY

[suprf1y]

Nice drill!

I've built a number of these systems and I never liked the idea of a fixed output. As RPM, load and HP increase, more water is required to do the same job.
So the last few I put together I used an automotive fuel pump and injector, machining a block with a boost referenced pressure regulator installed to return to tank, and a simple 555 timer chip based extra injector controller. It worked really well increasing pressure (injector flow) as boost increases and pulse rate with RPM. Aside from being able to choose the ideal injector sizing, with the injector controller circuit you can also increase and decrease the pulse rate based on the RPM input. Your AEM may even have a usable output for that.

[06YarisRS]

Originally Posted by suprf1y

Nice drill!

I've built a number of these systems and I never liked the idea of a fixed output. As RPM, load and HP increase, more water is required to do the same job.
So the last few I put together I used an automotive fuel pump and injector, machining a block with a boost referenced pressure regulator installed to return to tank, and a simple 555 timer chip based extra injector controller. It worked really well increasing pressure (injector flow) as boost increases and pulse rate with RPM. Aside from being able to choose the ideal injector sizing, with the injector controller circuit you can also increase and decrease the pulse rate based on the RPM input. Your AEM may even have a usable output for that.

Haha, you like the old Sears drill, eh? She's an oldie and doesn't even have reverse. Lol.

Yeah, I looked at the progressive systems and it would be ideal. My thinking here is that all I'm looking for is a little bit of extra protection during the partial boost, partial throttle stages. I have the F/IC set up to kick the pump in at around 3 psi. It will cover 3 - 7 ish psi and then the enrichment will look after the higher end. Once I'm up close to full throttle and in open loop, my afrs are in the mid to low 11s. What you did, I would love, but it's a bit beyond my skill level at this point. When you mention a 'useable output' from the F/IC, do you mean like a variable voltage output that could control the motor speed. I did inquire with AEM as to whether or not their progressive controller - that comes with their kits - would work with any pump. They told me that it would not as the pump is pwm controller.

Do you think my system will work? I am injecting water only through the M3 tip, pre-throttle body. I read that one only injects 1/2 the volume if using straight water as opposed to a 50/50 methanol mix. The M3 nozzle is rated at 1.6 gph @40 psi, or ~ 100 cc/min. I followed the recommendation that water is injected at a rate of 0.5 cc/hp. I have also figured out the rigging to easily plumb either one or two nozzles to spray on my intercooler. I just have to fabricate a couple simple brackets. The location is nice as it will also mist the rad and A/C condensor. I hope this is a good idea. My intention is not to advance timing or gain power in any way - for now. I just want a little extra security for the closed loop boost stages, especially on hot days.

I am proceeding with this setup, but I'd appreciate further thoughts from you if you're so inclined.