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The only real difference is adsorption is molecules binding to the surface of an object, in this case, activated charcoal. Absorption is molecules permeating and/or being completely broken down by an object.
Either one has a limit of ad/ab-sorption where the ad/ab-sorber becomes ineffective.
Sillica gel is an adsorbant that can be 'recharged' with heat in a moisture free area
I do not believe activated charcoal has any method of 'recharge'
In reply to Taiden:
The cannisters are designed to absorb the gas via the tank and during fill up, and then have then desorb the gas to the engine.
That's how they last 150k miles, and current ones (from the last decade or so) only leak <0.5g of gas over a 3 day soak in a hot chamber after being drive to full useful temp.
I have seen some data where in a normal FTP cycle, the cannister will lose over 100g of whatever it is storing.
No idea if it's charcoal or not, but that's what they do.
Just because the cannisters are labled "charcoal" does not mean that's all that is in there.
That's really cool! Thanks for the explanation.
I pulled one from a Paseo or Tercel or the like, since it had that stockish Toyota look and the ports were all the same.
pulled it on the 2 wheeled Bimmer. Word was that it was a liability if you overfilled your tank...can't remember exactly all the details. I've never smelled any fumes or seen any adverse effects. BTW all the BMW bikes like mine sold outside the US didn't have them in the first place
any mention of a charcoal canister gets my Limbaugh listening dad so mad he starts to spit
wow... your dad is a little extreme?
This has actually turned out to be a blessing in disguise. I have found a place for the OEM charcoal canister to fit behind the fender. It has also given me a chance to play with hardlines, as I am running hardlines in the engine bay to make it a very clean install.
The only missing piece to the puzzle is figuring out how I can effectively use the charcoal canister without a vacuum solenoid. I figure the megasquirt guys must have a trick they like to use.
Also, I am curious how you are supposed to put a hose barb end on hardline. Is there a special flare type tool for this?
Taiden wrote:Also, I am curious how you are supposed to put a hose barb end on hardline. Is there a special flare type tool for this?
Depending on the type of double-flaring tool you have, you might be able to do it. Just don't do the last step of finishing the fold into the flare.
In reply to Taiden:
MS should be able to drive a solenoid if you can find a location to put it into your manifold. If, I do undertand that's a very important word in this case.
But another if is IF you can create a very small depression in the intake so that it will draw slowly. To be a benefit at all- you don't need to draw that much out of the cannister.
Another thing to consider- does your MS run with O2 sensor feedback? This is another important consideration, when it comes to real application. While 99% of the time, you'll get a nominal flow out of the system, and probably won't matter much rich or lean- there's the probable chance that you'll get a slug of fuel every so often. Running with exhaust feedback will reduce the effect of this on your car- it wont run overly rich, and the opposite spike wont cause overly lean.
No megasquirt in the car just yet, that's likely a project for next summer. I just meant that those guys must have a simple fix that leaves the entire system functional without using up an output. My thought was to fill a male to male vacuum adapter with jb weld and drill a small hole to act as a restrictor. Then there are two vacuum lines that are directly in front of my throttle plates. (As in, less than 0.1" upstream from the closed plates.) I think that is the best place to run the purge line.
In reply to novaderrik:
Dido
same thing on multiple cars, no problem
cool.. glad you found a spot for it.
