thought i would chime in with my results after months of testing. I am new to these boards and my knowledge spanning 5 completely different home built systems and months of testing might be of help to some prospective HHO builders.
My vehicle is a 1998 Subaru Outback Sport with a 2.2l boxer engine
My Car
my HHO device is comprised of 13 3.5" by 7" plates wired (-)NNNNN(+)NNNNN(-) in nearly a half gallon 7/16" thick glass container with a teaspoon of naoh
HHO Container External View
HHO Internals
My system is wired in 10 guage wire through a 30 amp fuse, a 30 amp relay an ammeter, a stock 15amp (running lights always on) switch. It feeds the engine through a vaccum line on the intake manifold
Dashboard with switch and ammeter
My subaru without the system has never gained more than 25mpg and under normal driving conditions typically gets 24mpg.
With the system it put out 34mpg avg daily driving on 7 straight tests, and a 37mpg highway rating starting at 10 amp draw and increasing to 28 amp draw over the course of a 2 hour road trip on 2 tests. The system gives a substantial increase in throttle response that can be felt immediately.
I have checked my spark plugs and will say that the burn rate of the plugs appears to be ideal
Spark Plugs
I have had a water4gas spiral glass jar system, a stacked 7 plate lowes electrical plate system, a plexiglass 10 plate 5 baffled chamber -N NN NN NN N+ system, a 10 plate -NNNNNNNN+ with 1/8" spacers and now my 13 plate system.
A PWM controller is on order, not for its potential for greater mpg, but for its ability to control maximum amperage draw seeing that the system will increase amp draw as it heats up
I am from the bay area california and on a recent trip up to tahoe i tracked my subaru with 3 passengers geared for snowboarding with 3 boards on the rack and an 80mph romp up from 0 elevation to 6000 ft at 23mpg...thats approximately 600 pounds of extra weight and some wind drag, floored, up hill in windy conditions and I am thrilled!! b/c going up to the snow was the reason for the install
Things to know:
if you're blowing fuses try adding some neutral in close proximity to your anode and cathode, water is a semi conductor, it will conduct through your neutral plates producing hydrogen and at the same time lowering your amperage draw.
Balance your system, more neutral plates may require more electrolyte
scratching up your plates gives more surface area and promotes better flow
wire in a ammeter, kill switch, and pwm, will give you that "factory installed" feel of control and reliability
I am a dyi-er with limited knowledge in chemistry and automotive electrical but was capable of building this system myself, so have a can-do attitude
Hope this helped some people
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