looking for input on an HHO system

[rollertoaster]

Ok, this is my first post here, so go easy on me. I'm looking to boost the fuel economy of my 06 Honda Element AWD AT. I do what I can to improve my mileage, but my lifestyle contradicts it a bit. I'm an avid mountain biker, which means I usually have gear in my car, and bikes on the rack. I run my tires at about 35psi, and take my rear seats out of the car most of the time.

I drive 33mi each way to work and I drive too fast. I average between 20-22mpg. My mileage was better before the switch to ethanol mix. I turbo'ed the element last winter, and believe it or not it did not negatively affect my mileage. Basically, I've more than doubled my power with the same gas mileage. Now I'd like to improve my mileage and keep my horsepower. I have a piggyback computer on the car and a wideband a/f meter, so I can alter my A/F ratio to whatever I want, retard my timing etc...

I want to build an HHO generator to supplement my fuel usage. I want to system to only inject under part load (no idle or boost). My injectors are large at 650cc, and I can not decrease my duty cycle any further at idle. I don't want to add any during boost because I like my pistons and I don't want any holes in them. What kind of a/f ratio do I need to run with a HHO mixture?

Ok, so lets say at highway speed (70mph) my injector duty cycle is at 7-9% engine speed around 3000rpm. at my fuel pressure, that would equate to approx 180-200cc/min. How much HHO do I need to generate? I'm still reading up on HHO cells and I don't know what type to build yet, but I do not want it to draw more than 20 amps. I will be using a PWM regulator on the generator.

that's all I can think of for now. I'll update this more later as I think of more.

[GasSavers_BEEF]

given what you have said already, driving style could help you more than anything. telling you to slow down and stay out of boost is probably a waste of time.

I notice that you have a piggy back computer on your ECU, does this allow you to monitor your MPG in real time? if not then I would recomend that you get a scangauge. my wife has a honda element (completely different creature from yours I'm sure as it has 160hp) she has achieved 26 MPG on a tank. she doesn't take it easy on it but she doesn't dog it either. she does have an upper grill block.

on her vehicle, I noticed that the upper grill (the one with the honda symbol) doesn't have much behind it. I used a piece of plexi glass to cover it. I took time and cut out the shape of the honda symbol so that it protrudes through it and it looks descent. take a look at the pics in my garage under ellie mae.

I don't know that much about HHO other than the results seem to be inconclusive. you may find more help in the HHO section. there are a few guys on here that seem to be really into it.

[rollertoaster]

thanks, you're right about my driving style. Not, too much is gonna change there. I've tried slowing down etc.... really didn't help. I'm not in boost too much as I spend most of my time on the highway.
no I don't have a mpg gauge, but I can watch my duty cycle so thats a pretty good indication.
affraid I can't block any grills off. Turbos generate a lot of heat and need maximum air flow.

[GasSavers_BEEF]

do me a favor and look at your top grill. only about 1 inch of it is actually cooling the radiator.

regardless of that, check out scangauge.com many of us use it on this site. it will tell you all sorts of things. it will even tell you engine temp and IAT temps as well.

good little tool. as much money as you have in your vehicle, another $170 may be worth the info you get from it.

[rollertoaster]

Originally Posted by BEEF

do me a favor and look at your top grill. only about 1 inch of it is actually cooling the radiator.

regardless of that, check out scangauge.com many of us use it on this site. it will tell you all sorts of things. it will even tell you engine temp and IAT temps as well.

good little tool. as much money as you have in your vehicle, another $170 may be worth the info you get from it.

sorry, I didn't specify earlier. I removed the trim piece around the hood latch, the reason for this is to allow more airflow to the top and back of the engine (where the turbo is), not for the radiator. I was having really bad heatsoak issues, recently I also added a sti hood scoop ( my intercooler is mounted on top of the engine). I might put the divider back in and see if it helps now that it's getting cooler out, but I can't block the grill completely b/c I have driving lights mounted behind it. I'll also try to post some pics of my setup to give everyone an idea of what I'm working with.

I actually have an obd interface for my laptop already, and can read pretty much any parameter that I need to.