ejin4499 Posted January 3, 2012 Share Posted January 3, 2012 I've been toying with an idea of injecting a certain amount of pure O2 into the intake just before the mafs. would this make the engine run like it has a vacuum leak? Mafs sensor works off the idea that for a certain mass of air there is so much O2 present. right? By messing with the air mixture (CO2 O2 and N2 not air to gas mixture) would that throw the system off or would the O2 sensor see it and start compensating for it? N/m where I get the O2 at this point. Thanks Link to comment Share on other sites More sharing options...
1994SEV6 Posted January 3, 2012 Share Posted January 3, 2012 That's an extremely interesting Idea. I think your idea of the MAF is right. For the most part, air ALWAYS has 22% (or whatever it is) oxygen. This is a constant. If you have X amount of air passing through the MAF, then you have a directly proportional amount of oxygen. The MAF doesn't chemically know the difference between oxygen and nitrogen. If you put pure O2 through the MAF it would think it is 77% nitrogen. 77% of the pure O2 would be wasted. The injectors would not spray enough fuel to create a good fuel air ratio. The ratio would be 3x more biased towards oxygen. This might make a difference but it might not because it's the same. The fuel utilitizes the 22% oxygen and wastes the rest just as if it were nitrogen. Link to comment Share on other sites More sharing options...
frecklecolouredbrain Posted January 3, 2012 Share Posted January 3, 2012 Thats really tricky. How much O2 are we talking about? If its alot, then you MAF is going to assume that mix is 22% O2 and adjust fuel accordingly. However your O2 sensor wil read that you are burning lean. I have an 89 so im not sure if your eccs will adjust fuel based off the O2 sensor( mine doesn't). If it does, then you are back to square one. Also, without a way to adjust the oxygen flow with the throttle you are going to really mess up your fuel map. If its just a tiny bit of O2, inject it at an even flow after the MAF. This way if the O2 sensor can change the fuel ratio, it will do it based on the same mass of air(sans the extra O2). the result wil be slightly more fuel with slightly more oxygen to help it burn....if the eccs doesn't use the O2 sensor for fuel mapping, the mixture should just birn alot better and you'll be running a little lean. this could be very interesting. I look forward to reading about what happens...good luck mano. Link to comment Share on other sites More sharing options...
ejin4499 Posted January 3, 2012 Author Share Posted January 3, 2012 (edited) Assuming that the O2 sensor only has the ability to fine tune the fuel mixture what about putting a variable resistor on the mafs to tell the ecu that more air is being pulled in and then feed in the appropriate amount of O2. Thinking a little more about that once you figured out how much resistance to add you could put in just a regular resistor, as long as you had a constant feed of O2 for as long as the truck was running. For controlling how much O2 was being fed in I was thinking about using the part of the throttle where the cruise control attaches back to a valve that comes after a regulator. Or calibrate the regulator on the O2 tank and mount the variable resistor to the regulator in some elegant and clever way so that as I turn up the O2 it turns up the resistance. All of this assumes that putting a resistor on the maf will tell it that more air is going into the intake. Edit: Also doesn't the ecu try and maintain like 12:1 but stoich is 14:1. If so even just a little O2 might help a well maintained engine run a little better? Edited January 3, 2012 by ejin4499 Link to comment Share on other sites More sharing options...
Precise1 Posted January 4, 2012 Share Posted January 4, 2012 Assuming that the O2 sensor only has the ability to fine tune the fuel mixture what about putting a variable resistor on the mafs to tell the ecu that more air is being pulled in and then feed in the appropriate amount of O2. As simple as the WD21 systems are, I think you'll find they are more dynamic than that. I don't think it matters pre or post MAF because you are talking about a system that runs hundreds of CFM through a 2" opening so it is not going to notice if you introduce a trickle of O2. What will notice (if anything) is the O2 sensor and there isn't much of a way around that without replacing the ECU with a Nistune or whatever the aftermarket ecus are called. People have installed VG33s in WD21s with all the VG30 components and they run well, so the system can adjust for at least 10% displacement change. I doubt you will see a significant performance gain injecting a little O2, but it might help over all gas mileage... B Link to comment Share on other sites More sharing options...
sewebster Posted January 4, 2012 Share Posted January 4, 2012 21% oxygen Link to comment Share on other sites More sharing options...
ejin4499 Posted January 4, 2012 Author Share Posted January 4, 2012 I don't think it matters pre or post MAF because you are talking about a system that runs hundreds of CFM through a 2" opening B Do you happen to know how much cfm they do flow through that? If I want to be able to make a worthwhile experiment I need to be able to figure out how much O2 would be required to make a difference. I'm thinking I want to try getting up to 25 30 40 and 50% O2 in the intake charge. If I can get it up to 50% O2 that would be like more than doubling how much air gets into the engine without using any kind of turbo or super and staying smog legal. On the other side if I can only push the stock ecm so hard I would like to know how hard. Then one of these guys who doesn't have to deal with CA smog can try and go further. Link to comment Share on other sites More sharing options...
Precise1 Posted January 4, 2012 Share Posted January 4, 2012 200-350 depending... http://www.4secondsflat.com/Carb_CFM_Calculator.html 50% O2 would take some serious tanks for anything other than a moments effect. I'm not a tuner but with these, generally speaking, go turbo or go home... Seriously, intake, cam, headers, exhaust is about as much as you can do in smog areas and that won't even get you to 200hp. A 3.3L with the same might. I plan to try it someday... B Link to comment Share on other sites More sharing options...
ejin4499 Posted January 4, 2012 Author Share Posted January 4, 2012 (edited) 200-350 depending... http://www.4secondsflat.com/Carb_CFM_Calculator.html 50% O2 would take some serious tanks for anything other than a moments effect. I'm not a tuner but with these, generally speaking, go turbo or go home... Seriously, intake, cam, headers, exhaust is about as much as you can do in smog areas and that won't even get you to 200hp. A 3.3L with the same might. I plan to try it someday... B Someone check my math on this. If we are flowing approx 280 cfm at 6000 rpm at 21%O2 that means that we are getting about 58.8 cfm of O2. If I displace some of the atmosphere with O2 say 49 cfm O2 that would give me an intake from atmosphere of about 231 cfm 21%O2 = 48 cfm O2. So to double the amount of O2 coming into the air intake I only need to push about 49 cfm pure O2. Am I right on that? Edit: doing a little more math means that in order to supply this with enough O2 to double the charge I would need about 4 pounds of O2 at STP per minute. So either a reformer or a trailer full of solar panels and tank of water. Dang!!! Thanks B for the calculator. Edited January 4, 2012 by ejin4499 Link to comment Share on other sites More sharing options...
Precise1 Posted January 4, 2012 Share Posted January 4, 2012 You are welcome, and yeah, you figured out what I was saying. If you have any experience with shop tools, hungry ones will use 15+ CFM @90 psi so 50 CFM is a massive draw. B Link to comment Share on other sites More sharing options...
SchizophrenicMC Posted January 5, 2012 Share Posted January 5, 2012 If you're adding an oxidizer, you'll need to add an aftermarket fuel management system, more often than not. This applies to Nitrous Oxide systems, pure O2 systems, and the like. You can generally get away with small amounts of forced induction, or improved cams, on stock computers, but when you get into heftier mods like high-boost, or oxidizer, you'll need to change your engine management system to compensate. That being said, if you're running a fairly small amount of oxidizer, you might try larger fuel injectors on the stock pulse, to accommodate the artificial lean condition you'd be creating. Link to comment Share on other sites More sharing options...
ejin4499 Posted January 5, 2012 Author Share Posted January 5, 2012 I think I'll abandon the project. Part of the reason I was looking at it is I can produce almost pure O2 for free using a solar cell I have. I would need way more cells in order to make enough O2 for this to be a worthwhile project but it was a cool mind experiment. If anyone comes up with another way to do this cheap I'm totaly willing to pick it back up. Link to comment Share on other sites More sharing options...
silverton Posted January 5, 2012 Share Posted January 5, 2012 on a stock ECU controlled injection system, the O2 sensor would compensate by adding more fuel due to it seeing all the extra oxygen in the exhaust gases. you'll end up with a horribly running truck getting single digit MPG's. Link to comment Share on other sites More sharing options...
ejin4499 Posted January 6, 2012 Author Share Posted January 6, 2012 on a stock ECU controlled injection system, the O2 sensor would compensate by adding more fuel due to it seeing all the extra oxygen in the exhaust gases. you'll end up with a horribly running truck getting single digit MPG's. And what do you base your opinion on? More oxygen + more gas = more power until the thing blows up was my line of thinking. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now