DIY_EFI Digest Monday, September 13 1999 Volume 04 : Number 521 In this issue: Re: MAF offset Re: DIY_EFI Digest V4 #520 Re: DIY_EFI Digest V4 #518 Re: DIY_EFI Digest V4 #520 See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Sun, 12 Sep 1999 14:43:29 +0000 From: "Alex C. Peper" Subject: Re: MAF offset I cut the MAF line and placed a A/D - micro. - D/A in the line. This is known as intercept method. You can modify the input to what ever output you want. O2 voltage, RPM, and water temp were other inputs, but only one output. I am not sure what would happen if you tapped the O2 line into the MAF. For cold start and safety I used a normally closed bypass relay I might be doing some more work on this in future, if you need a simple offset box for small donation let me know. Alex > Date: Sat, 11 Sep 1999 18:53:55 -0400 > From: bjanesi@xxx.com > Subject: Re: Bosch MAF for VAF swap > > Hi Alex- > > Thanks for the response. Although I have a basic understanding of > electronics, I'm not an electrical design engineer, so this is probably a > bit over my head. Tying the MAF output to the O2 sensor output does > sound interesting though, but what about cold start-up when running open > loop? I guess there would have to be a default setting for open loop. > > I know the Split Second Co. has a control box with 3 different pots; I > believe one sets the base idle, one sets mid-range, and the 3rd sets > voltage at maximum air-flow. Fine tuning is done primarily via > observation of an O2 sensor meter, so it is a manual approach to what it > sounds like you have done automatically with the adaptive feedback. > > Any chance you have a schematic on any of this? Any info would be > appreciated. > > Thanks again, > > Brad (brad.anesi@xxx.com <--- use this address if sending attachments) > Alex C Peper http://www.obd-2.com ------------------------------ Date: Sun, 12 Sep 1999 17:36:24 -0400 (EDT) From: William T Wilson Subject: Re: DIY_EFI Digest V4 #520 On Sun, 12 Sep 1999, DIY_EFI Digest wrote: > > I don't know why they can't. I can; it violates the Second Law of > > Thermodynamics. Entropy has to increase. That engine decreases entropy > > by converting heat energy into rotational energy. The engine has to > > output entropy somewhere. > > You can convert heat energy into rotational energy easily enough... > it's what you car engine does. There is a lot of heat energy to > convert though. Yeah, but the car engine does this by starting with comparatively well ordered heat energy. The air inside the combustion chamber is hot, the air outside is not. After one complete power stroke (all 4 cycles from intake to exhaust) suddenly the air outside the combustion chamber is a little hotter and the air inside has all been pumped out. Some of that energy is converted to rotation, but some of it just contributed to global warming. Entropy has increased and the second law is happy. This engine does the reverse. It takes regular air, magically extracts the heat from it, then turns it into rotational energy and blows out the cold air. Entropy has decreased because you've taken unordered heat energy and converted it not only into rotation but into ordered heat, too. That's against the rules. > I suspect that there isn't enough heat energy in ambient air > to drive it through their system and have any energy left over. There's tons of heat energy in ambient air. You just can't use it for anything other than heating stuff. :} ------------------------------ Date: Sat, 11 Sep 1999 07:40:49 -0600 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: DIY_EFI Digest V4 #518 >Date: Fri, 10 Sep 1999 15:24:29 -0700 >From: "John Dammeyer" >Subject: Vapour Pressure > >Hi All, > >Does anyone have the formulae for Vapor Pressure? If I assume RH is 75% >and can >measure the Air Temperature inside the intake manifold what is the calculation >for vp? > >Thanks, > >John You need some combination of psychrometric charts or GOOD steam tables. A good steam table will include a section giving the equations upon which the values stated in the tables are based. If RH is 75%, the VP will be 75% of the VP (partial pressure of H2O vapor) at saturated conditions for that temp. Greg ------------------------------ Date: Sun, 12 Sep 1999 09:07:41 -0600 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: DIY_EFI Digest V4 #520 >DIY_EFI Digest Sunday, September 12 1999 Volume 04 : Number 520 > > > >In this issue: > > Re: Wired foo > Re: Bosch MAF for VAF swap > Re: Bosch MAF for VAF > >See the end of the digest for information on subscribing to the >DIY_EFI or DIY_EFI-Digest mailing lists. > >---------------------------------------------------------------------- > >Date: Sat, 11 Sep 1999 13:47:32 -0700 (PDT) >From: Orin Eman >Subject: Re: Wired foo > >> On Sat, 11 Sep 1999, DIY_EFI Digest wrote: > >> > Naturally, the experts think it's too good to be true -- although they >> > can't exactly say why. > >> I don't know why they can't. I can; it violates the Second Law of >> Thermodynamics. Entropy has to increase. That engine decreases entropy >> by converting heat energy into rotational energy. The engine has to >> output entropy somewhere. > >You can convert heat energy into rotational energy easily enough... >it's what you car engine does. There is a lot of heat energy to >convert though. > >I suspect that there isn't enough heat energy in ambient air >to drive it through their system and have any energy left over. >In fact, I'd guess you would have to input energy. > >Imagine if it did work - a self-powered refrigerator! > >Orin. > The second law of thermo is the only law of physics that hasn't changed since the time of Newton. Somehow, I doubt that this guy has found a glitsch in what Sir Isaac wrote! If he has--more power to him, he will surely be way wealthier than Bill Gate$!! If not, his investors will be somewhat poorer, and angrier. I'm not gonna hold by breath to see the thing work as claimed! Greg ------------------------------ End of DIY_EFI Digest V4 #521 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. A non-digest (direct mail) version of this list is also available; to subscribe to that instead, replace "diy_efi-digest" in the command above with "diy_efi".