Senior Member
Sounds good. Man, I really hope we can make some ground here. This is so frustrating.
I really want to get several opinions on how this device would work to control vacuum on my system. Anyone want to have at it?
http://www.grainger.com/Grainger/items/5Z763
Give a man a match, and he’ll be warm for a minute, but set him on fire, and he’ll be warm for the rest of his life.
2000 Pontiac Grand Prix GTP 3.8L SII S/C'd
15%-20% MPG increase at 1.5 Amps
2000 Jeep Grand Cherokee Limited 4.7L V8
No gains.
Matt you're right about that relief valve. It will just let air into the genny to keep the vacuum at the preset level, which effectively creates a vacuum leak whenever the relief valve opens. Combine that with a restriction (ball valve) on the vacuum source and you will have a controlled intermittent vacuum leak. That sounds bad but honestly it probably wouldn't be enough to cause a problem. The only bad thing is, when you floor it and manifold vacuum drops, the vacuum still present in the genny will suck air FROM the intake through the restriction to equalize the pressure, which means on sudden acceleration or heavy load you'll lose HHO delivery for a short time.
As far as the intelligence level of modern PCMs, they are incredibly smart but lack common sense. They do monitor the sensors directly for "out-of-range" issues, as well as comparing the readings to other sensor conditions as a sort of reality check. They will also check for certain sensor changes during certain operating conditions....for instance, the O2 readings should spike lean when the EGR valve is commanded to open. If the PCM doesn't see what it expects, it will set codes. However, the simplest things can go unnoticed. I see Ford products all the time with high/rough idle and stalling problems caused by severe vacuum leaks (they have a known problem with the PCV hoses rotting away due to oil vapor exposure.) These often come in with no check engine light and no fault codes set, even though the engine will die anytime you let off the throttle suddenly. You'd think that would be an obvious sign that something's wrong, but the computer doesn't pick up on it.
Senior Member
I'm thinking about giving it a shot. I was surfing around and I stumbled upon a device called a non-relieving vacuum regulator. From what I read, it doesn't vent to atmospheric pressure to acheive the desired vacuum. The one I saw was an big industrial one though. I want to do some more poking around to see if I can find one that's a little more precision and MUCH less expensive.
One complication leads to another. Gotta love it.
In regard to what you were saying about the vacuum leak, etc. I guess I'll just have to but a brick behind my gas pedal so I can't floor it anymore!I don't think I should be expecting to get good MPG like that anyway.
Give a man a match, and he’ll be warm for a minute, but set him on fire, and he’ll be warm for the rest of his life.
2000 Pontiac Grand Prix GTP 3.8L SII S/C'd
15%-20% MPG increase at 1.5 Amps
2000 Jeep Grand Cherokee Limited 4.7L V8
No gains.
Senior Member
I know that there is a whole measurment system to measure vacuum pressure, but I have no idea how to quantify any of it. How much vacuum will a manifold generate in the unit of vacuum measure?
I was looking at this regulator which provides all it's specs but I have no clue how it compares to what a manifold will do:
Click Here
Here's another one I'd like to hear opinions on:
Click Here
Help?
Give a man a match, and he’ll be warm for a minute, but set him on fire, and he’ll be warm for the rest of his life.
2000 Pontiac Grand Prix GTP 3.8L SII S/C'd
15%-20% MPG increase at 1.5 Amps
2000 Jeep Grand Cherokee Limited 4.7L V8
No gains.
Actually there are a few different measurement standards for vacuum. Inches of mercury ("Hg) is still the most common in the US, inches of water is also used for high-precision measurements. 0"Hg is atmospheric pressure, total vacuum is ~30"Hg. The rest of the world uses pascals or kilopascals (kPa) which is the metric measurement for both pressure and vacuum.
Automakers don't even use the concept of vacuum anymore when it comes to engines....it's all done in abolute pressure. Total vacuum is no pressure, or 0kPa. Atmospheric pressure (no vacuum) is 101kPa absolute (give or take depending on elevation and weather conditions.) This is a bit confusing at first (it seems kinda backwards,) but it's really much simpler once you get your head around the concept that vacuum doesn't exist. It's just a name for a space with less pressure than another space. This is where the name MAP sensor comes in....it stands for Manifold Absolute Pressure.
On those regulators...the first is a bleed-air type regulator which means it just leaks in air to keep the vacuum under control. Not good for automotive purposes. The second one may be more reasonable, but it's a bit bulky looking.
For reference, most engines idle at around 20-22"Hg which is a MAP of ~30kPa. It can spike lower than that on sudden deceleration, my IROC has shown as low as 8kPa while tuning. WOT will typically show MAP readings around 98-100kPa (0-1"Hg.)
Senior Member
So with a rating of -100 to 1.3 kPa, I should be okay? So if I'm shopping around, just try to make sure that it can handle at least 100 (+/-) kpa?
I dunno boys, I'm to the point to where I think I just might have to accept defeat on this @*#$ Jeep. I'm just not seeing anything realistic that will make all this hassle worth a few bucks in MPG.
If there was a solid apparatus that could handle this vacuum issue, maybe, but I have looked and looked and shopped and called and no one can really offer any solutions. The only other solution I can think of is to COMPLETELY start over and build a whole new system that can withstand any vacuum an engine could dish out. IF I ever get to that point it will be far down the road after all I've financially invested into this already. For me it's becoming a matter of loss control. The whole point I've done HHO is to try to SAVE money!
I've learned a lot, that's for sure. If I had an HHO friendly vehicle, it would definitely be worth it. I guess as it is, I'm still reducing emissions to a certain degree, I'm just not saving any MPG, right?
I just read Smith's latest update about how his engine is doing after removing the HHO from this engine. Kinda depressing. I made myself a "deal" when I first started this. In order for it to be worth the time and effort, it had to be A - a way to save money in fuel costs, B - it had to be completely reversable for re-sale purposes, C - had to be safe, D - had to require a reasonable to little maintenance. It doesn't look like in the case of my Jeep I'm meeting that criterion.
My car has the identical system so I have the same problem there. I did, however, see a slight improvement in MPG so I'll keep it in the car. Hopefully my future cars are more HHO friendly.
Give a man a match, and he’ll be warm for a minute, but set him on fire, and he’ll be warm for the rest of his life.
2000 Pontiac Grand Prix GTP 3.8L SII S/C'd
15%-20% MPG increase at 1.5 Amps
2000 Jeep Grand Cherokee Limited 4.7L V8
No gains.
Senior Member
Hoper, how much output are you getting out of your HHO gen??
over in Painless' thread, he made mention that he closed the ball valve completely, let some pressure build up in his gen for a short time, then opened it fully and really noticed his truck run differently but briefly... (in his Painless experiment thread)
what i'm wondering for you and him is if your gens are putting enough HHO into the motor?? i know his is around 1.5 LPM and i'm not sure about yours, but what if you had enough stuff to build 2 of yours, or whatever.. and give these stubborn hogs about 3 LPM ?? just to see if it would respond positive or negative... if we can just get it to do something, then we can alter fuel ratios etc...
what do you think???
mike
Super Moderator
I'm running 2.3 LPM into mine...Originally Posted by daddymikey1975
Senior Member
Oh wow... for some reason i thought you were only at 1.3... that's so bizarre that you're stuffing that much stuff into your truck and it has no idea... what a dumba$$ truck LOL...
still kind of odd that when you closed your ball valve for a minute, then opened it up you definitely noticed your truck respond....
i'll think on that for a day... unless you come up with something else.. i dunno.. wonder what Smith03jetta thinks about this...
mike
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