DIY_EFI Digest Monday, 15 July 1996 Volume 01 : Number 198 In this issue: Report on failed mail Info needed on NTK EGO sensor GMP4 ECM '89 HELP?!? oil control Re: RE: EFI Re: GMP4 ECM '89 HELP?!? RE: DIY_EFI Digest V1 #197 Re: oil control Re: GMP4 ECM '89 HELP?!? Re: oil control Re: RE: EFI Re: oil control Re: RE: EFI Re: RE: EFI Re: RE: EFI ignition coil? See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: nmail-daemon@xxx.com Date: Sun, 14 Jul 96 05:44:44 EDT Subject: Report on failed mail Errors were detected when processing your mail message which was entered at 11-JUL-1996 05:35 From: US4RMC::"diy_efi@xxx.edu" To: DIY_EFI-Digest@xxx.edu Subj: DIY_EFI Digest V1 #195 - ---------------- The following error message was returned whilst sending to address SPESHR::M_MCDONALD %MAIL-E-OPENOUT, error opening !AS as output -RMS-E-CRE, ACP file create failed -SYSTEM-F-EXDISKQUOTA, disk quota exceeded This is a soft error, but the retry period has expired. No more attempts to send to this address will be made. - ---------------- The text of your failed mail message follows: DIY_EFI Digest Thursday, 11 July 1996 Volume 01 : Number 195 In this issue: Jim Conforti, are you out there? Re: Jim Conforti, are you out there? Re: GM Mass Airflow Sensor Re: Bosch ECU Schematics Bosch Motronic AFM Spring Tension - Further Comments Re: cypress FPGA tools GM Mass Airflow Sensor - Donde Esta? Re: GM Mass Airflow Sensor Re: Bosch ECU Schematics Re: GM Mass Airflow Sensor - Donde Esta? Looking for info on GM ECMs See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. - ---------------------------------------------------------------------- From: Donald Whisnant Date: Wed, 10 Jul 1996 10:05:54 -0400 Subject: Jim Conforti, are you out there? Jim Conforti... Are you out there on the list? Several other DIY_EFI members said you might could answer some of my questions. I've been trying your email address as posted in the archives, but with no success (it keeps telling me "unknown user")... If you are out there, please email me... Donald Whisnant dewhisna@xxx.com - ------------------------------ From: Land Shark Date: Wed, 10 Jul 1996 09:04:49 -0600 Subject: Re: Jim Conforti, are you out there? At 10:05 AM 7/10/96 -0400, you wrote: >Jim Conforti... Are you out there on the list? Sure am .. address is .. lndshrk@xxx. Note .. that is LNDSHRK .. as in LAND SHARK :) Jim - ------------------------------ From: jimmy staton Date: Wed, 10 Jul 1996 17:02:49 -0500 Subject: Re: GM Mass Airflow Sensor RABBITT_Andrew@xxx.au wrote: > > >>>I'm curious if anybody has a clue as to the upper (frequency > output) limit of the currently used GM mass-airflow sensor.<<< > > does 9600 Hz make any sense? the GM manual I have has the freq listed as 30HZ-150HZ unless that has changed, last 1 I checked was out of an 1982 Firebird and that was right. - ------------------------------ From: michael glidewell Date: Wed, 10 Jul 1996 18:09:19 -0400 Subject: Re: Bosch ECU Schematics At 02:31 PM 6/11/96 +0000, you wrote: >I am looking for Bosch ECU Schematics for the following cars: > >BMW 530i, 1978 >Datsun 280Z, 1975-1978 >Datsun/Nissan 280ZX, 1979-1983 (incl. turbo). > >If anyone has any schematics for the ECUs for these cars, any or all >of them, in any format, please let me know. Also, if anyone knows of >any good source of information on these systems, I'd love to see it. > >Thanks. >_____________________________________________________________________________ >Josh Karnes joshk@xxx.com >Renaissance Man http://www.tanisys.com/~joshk/home.htm >Tanisys Technology http://www.tanisys.com >Austin, Texas '78 BMW 530i | '72 Datsun 240Z | IZCC #308 >_____________________________________________________________________________ > *** opinions expressed herein are MINE, ALL MINE!! *** > Josh: Did you ever find a source for schematics?? I'm looking too. - - ---------------------------------------------- Michael Glidewell Boston, Massachusetts glide@xxx.net KE1CP BMW 528i BMWCCA http://www.shore.net/~glide/ - ------------------------------ From: Brad Anesi Date: Wed, 10 Jul 1996 16:28:21 -0600 Subject: Bosch Motronic AFM Spring Tension - Further Comments Herewith the opinion of Don (ex-Alfa, now Fiat R&D): The EFI discussion is difficult: one must first know if the system is analog or digital and to which degree of autoadaptivity is provided. Example: Fiat uses/has used _many_ executions of Bosch Motronic alone, many L-Jet, Monotronic, Weber-Marelli, Rochester, Hitachi.... Maybe this will help: 1. Forget that the closed loop O2 sensor function will correct, in the end, any minor changes upstream. It will, but that does not seem to be the issue. We talk open loop. 2. Spring tension makes a difference only during _transient_ movement and will enrichen until steady state, where it has no effect. There is no effect at WOT as you are already using the longest pulse found in the look-up table (MAP) for that set of parameters. 3. Remember, electrons are faster than air! 4. The base calibration is not always based on vane position: depends on system. 5. Even open-loop, later generations use autoadaptivity, which further permits default corrections for components operating outside their spec. ranges, within the ROM map. 6. Aside from AFM vs inputs to controller, this signal is further corrected by rpm, load, temps, etc., always cross-checking table for correct fuel delivery before the O2 sensor. 7. To see the effects, get a J.C. Whitney A/F checker. 8. In systems with separate ignition controllers, more benefits can be had by changing the spark map. 9. Significant changes cannot be made by DIY, nor without a dyno. 10. Perceptions and stop-watch times do not always concur. 11. There are other ways of increasing fuel delivery such as raising rail pressure, larger nozzles, with larger AFM. But the intake runners and valves have to be sized accordingly. 12. Our experiences with DIY modified EFI systems do not yield measurable differences. Conclusion: for DIY, it seems more cost effective to use carburetors and a modern ignition system, leaving original EFI system intact for use later at resale. - ------------------------------ From: Darrell Norquay Date: Wed, 10 Jul 96 21:40 PDT Subject: Re: cypress FPGA tools At 01:20 PM 7/8/96 CDT, Steve Ravet wrote: >I just got v4.0 of the VHDL compiler. I haven't used it much, but it >appears to be.... A VHDL compiler. :-) It supports all the Cypress >chips, including PALs, CPLDs, and FPGAs. I think you need additional >software to really do your own FPGAs, though (like floorplanning and timing >analysis). But for CPLDs it's a complete package including simulator. Don't you mean Warp2? Warp4 is the full enchilada, timing simulator and all, and it sells for US$5000! I know, 'cause I just took a Cypress VHDL seminar last week, and got a copy of Warp2, along with a CD full of libraries, Warp2 for several platforms including the MAC and Sun, the VHDL text, and a 1 day intensive VHDL course for CDN$99. >The download cable/software wasn't available at the time, although it >should be now. I need to call back and see. The download cable/software >works with all of the Cypress "ISR" chips (in system reprogrammable). The guys at the seminar gave me the impression that they haven't released their ISP devices yet, due out in August, I think. They didn't mention the download cable + software. Warp2 just generates JEDEC files which you need a pricey device programmer to use. >I'd recommend this package to anyone interested, esp. since the price is >reasonable. It was about $116 US with shipping, and it includes a textbook >published by Addison Wesley about VHDL on programmable logic. The download >software and cable is another $100, and only runs on PC type platforms. >The WARP software itself is available for PCs or several workstations. Yeah, I'd second that, especially if ya got a buddy with a programmer like I do. Now I just have to sit down and really get into the VHDL coding, which may take a while... Should save a bagfull of glue logic on my next 'HC11 project. regards dn - ------------------------------ From: Darrell Norquay Date: Wed, 10 Jul 96 21:40 PDT Subject: GM Mass Airflow Sensor - Donde Esta? Yo All: I'm frantically (well, not really frantic yet) trying to locate part numbers, years, makes, and models of GM's that used the frequency output MAF sensors. I'm trying to scare one up out of a boneyard, so far no luck. The bigger the list I can come up with, the better my chances of finding one. Some of the models I've tried are: 94-96 Camaro 96 Vortech engines 84-85 Buick Turbo 3.8L V6 Some of these are newer vehicles, they are scarce in the local boneyards, as are the Turbo units. Something mid-80'ish would be nice. Someone just mentioned the 82 Firebird as having this unit, but no luck there either. I assume from recent threads on this list that this is relatively common in GM's, I was under the impression that GM's mostly used analog output MAF's. If you can't supply model info directly, any reference materials which supply the info or aftermarket replacement PN's would also be greatly appreciated. regards dn BTW, I'm not really limited to GM's, anything suitable for a 300-400HP 350 cu in V8 (500-700 CFM flow capability) would work. Small V6's or 4 cyl units probably would not be suitable. - ------------------------------ From: John Dammeyer Date: Wed, 10 Jul 96 23:33 PDT Subject: Re: GM Mass Airflow Sensor At 05:02 PM 10/07/1996 -0500, you wrote: >RABBITT_Andrew@xxx.au wrote: >> >> >>>I'm curious if anybody has a clue as to the upper (frequency >> output) limit of the currently used GM mass-airflow sensor.<<< >> >> does 9600 Hz make any sense? > >the GM manual I have has the freq listed as 30HZ-150HZ unless that has >changed, last 1 I checked was out of an 1982 Firebird and that was >right. I always thought that a Mass Flow Sensor used a hot wire type aneomometer which would just result in a voltage output to be measured by an A/D convertor. What type puts out a frequency? Thanks, John. Pioneers are the ones, face down in the mud, with arrows in their backs. Automation Artisans Inc. Ph. 604-544-4950 6468 Loganberry Place Fax 604-544-4954 Victoria BC CANADA V8Z 7E6 - ------------------------------ From: John Dammeyer Date: Wed, 10 Jul 96 23:33 PDT Subject: Re: Bosch ECU Schematics At 06:09 PM 10/07/1996 -0400, you wrote: >At 02:31 PM 6/11/96 +0000, you wrote: >>I am looking for Bosch ECU Schematics for the following cars: >> >>BMW 530i, 1978 >>Datsun 280Z, 1975-1978 >>Datsun/Nissan 280ZX, 1979-1983 (incl. turbo). >> >>If anyone has any schematics for the ECUs for these cars, any or all >>of them, in any format, please let me know. Also, if anyone knows of >>any good source of information on these systems, I'd love to see it. >> As I understand it the Bosch uses the CAN bus for communications. Your first step in reverse engineering or even monitoring the system would be to determine which two wires make up RT+ and RT-. Then attach a suitable CAN card monitor and eavesdrop. Coupled with logging other real time info such as engine RPM there is a likelyhood that you would be able to determine which messages say what. But.... other than reporting some sort of status or replacing completely a particular module I'm not sure what you'd do with it. John. Pioneers are the ones, face down in the mud, with arrows in their backs. Automation Artisans Inc. Ph. 604-544-4950 6468 Loganberry Place Fax 604-544-4954 Victoria BC CANADA V8Z 7E6 - ------------------------------ From: peter paul fenske Date: Wed, 10 Jul 1996 22:41:03 -0700 Subject: Re: GM Mass Airflow Sensor - Donde Esta? > >regards >dn > >BTW, I'm not really limited to GM's, anything suitable for a 300-400HP 350 >cu in V8 (500-700 CFM flow capability) would work. Small V6's or 4 cyl >units probably would not be suitable. > > >************************************************************************** Hi: Try fords hitachi based MAF. I believe they have a var freq output good to about 300 HP. Stocks are cheap. And aftermarket in 200$ range. Hp good to 400. GL: peter - ------------------------------ From: "Oliver Scholz" Date: Thu, 11 Jul 1996 09:55:06 +0200 Subject: Looking for info on GM ECMs Hello group, I am new to this list, and I hope to gain useful information from it and maybe provide some as well. I am looking for information on GM ECUs used in the Pontiac Fiero. As far as I know there are 3 different ECUs used: * one for the 1985-1988 V6 * one for the 1984-1986 L4 * one for the 1987/1988 L4 with DIS Does anyone have information on the datastream generated by these? I would be particularly interested in the 1987/88 datastream? I am also curious as to the content of the PROM. Does anyone know what is in those and at what locations? Thank you. Best regards, - - -Oliver - ------------------------------ End of DIY_EFI Digest V1 #195 ***************************** 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". % ====== Internet headers and postmarks (see DECWRL::GATEWAY.DOC) ====== % Received: from mail11.digital.com by us4rmc.pko.dec.com (5.65/rmc-22feb94) id AA23339; Thu, 11 Jul 96 05:27:36 -040 % Received: from coulomb.eng.ohio-state.edu by mail11.digital.com (8.7.5/UNX 1.2/1.0/WV) id FAA31354; Thu, 11 Jul 1996 05:23:32 -0400 (EDT % Received: by coulomb.eng.ohio-state.edu (940816.SGI.8.6.9/940406.SGI) for diy_efi-digest-outgoing id JAA10458; Thu, 11 Jul 1996 09:00:12 GM % Received: by coulomb.eng.ohio-state.edu (940816.SGI.8.6.9/940406.SGI) for DIY_EFI-Digest-Send@xxx.edu id JAA10445; Thu, 11 Jul 1996 09:00:08 GM % Date: Thu, 11 Jul 1996 09:00:08 GMT % Message-Id: <199607110900.JAA10445@xxx.edu> % From: DIY_EFI-Digest-Owner@xxx.edu % To: DIY_EFI-Digest@xxx.edu % Subject: DIY_EFI Digest V1 #195 % Sender: owner-diy_efi-digest@xxx.edu % Precedence: bulk % Reply-To: diy_efi@xxx.edu ------------------------------ From: Asko T Heikola Date: Sun, 14 Jul 1996 19:22:33 +0300 (EET DST) Subject: Info needed on NTK EGO sensor Hi there! I have NTK EGO 4-wire sensor from Opel Vectra (I believe it is called Vauxhall Vectra in UK). It's quite new (-96), and has markings and part numbers from GM, Siemens and NTK. The colors of the wires are: Red, black, yellow and white. I have a reason to believe that it is of a heated type, since there is a marking 12V printed on it. The yellow wire is signal and the black wire is signal ground (probably isolated ground -type). It seems to work well with A/F-meter I've built (using LM3914), but I've been having problems with the heating (?) wires. Does anybody know the wiring diagram or place where I would get one? Thanks in advance! Asko Heikola ------------------------------ From: Dave Zug Date: Sun, 14 Jul 1996 16:08:26 -0400 Subject: GMP4 ECM '89 HELP?!? hello, i'm new.. heres the short version of my quest: I have an 89 pontiac grand prix turbo 3.1L. it uses a GMP4 ECM and i have been trying to modify the "usual parameters" as it is called in one of the messages i read in the archives of this mailing list..the spark advance, the injector tables, the turbo boost limit, fans, TCC lockup ... ... ... Anyway, i have READ the prom, and can see tables(though i dont know which is which), i can burn a duplicate chip (its a 27c256, mounted in the mem-cal next to the ELECTRONIC SPARK CONTROL module) but every chip i burn with even one value changed, causes the ecm to go into "limp home" mode i think. i beleice the checksum has something to do with it, but i dont know where the checksum is! i dont know how i'll ever find the 15 pound boost limit setting, or find out which table is what unless i can make subtle changes and burn a chip..the checksum is keeping me from doing that! for info: the grand national 3.8L turbo and the TTA 3.8L turbo use different ECM's with 4k eeproms, my ECM is a different type. what i guess i need is to fing the original programmer and get him to give me all the data he has! yea right. any help would be great thanks! ------------------------------ From: "William A. Sarkozy" Date: Sun, 14 Jul 1996 16:35:27 -0700 Subject: oil control Hey all you turbo gurus...... Anybody have trouble containing oil in the turbos? I have a setup with 2 brand-new turbos that leak oil badly into the hot section causing great billows of blue smoke. Application is SBC with high volume oil pump which delivers about 90 PSI cold. Oil supply lines are #4AN and drains are #6AN back to top of oil pan just below the block. I'm having trouble believing that BOTH units could have been assembled improperly. Is the oil seal a mechanical unit or does it have some sort of "packing gland" that can be replaced? Could I have damaged it by excessive pressure, or could I just turn down the pressure and hopefully solve the problem? I've never read anywhere that too much oil (pressure) is bad for these things. Thanks in advance for any help you might provide..... Bill ------------------------------ From: "Woodd, Michael" Date: Mon, 15 Jul 1996 08:41:00 +1200 Subject: Re: RE: EFI >>2. Spring tension makes a difference only during _transient_ movement and >>will enrichen until steady state, where it has no effect. There is no >>effect at WOT as you are already using the longest pulse found in the >>look-up table (MAP) for that set of parameters. > > Umm .. Motronic does NOT look up PULSE WIDTHS .. > > It MEASURES air .. calculates LOAD from AIR and RPM and a constant (based > upon injector size) then corrects for operation conditions (maps) > to yeild injector PW .. Sorry, but I have to ask (forgive my ignorance, I am not a car tuner, nor an engine expert of any kind, and what I know about MAP (manifold air pressure?) fuel injection systems could be written in 40 point on the back of a thumb tack) - I hope to get a comprehensive answer from someone with wisdom in such things, please expound at length to me in person if you like (and no, I am not taking the piss out of anyone except myself): 1. How exactly would the controller calculate "load" from "air" and "rpm" and "a constant"? i.e. what would the equation be? (please treat me as completely ignorant, though I am not quite) (I assume "load" refers to the air volume passing into the engine) 2. How would you work out what this constant is? 3. Also, I am confused as to why the calculation of load would depend on a constant upon injector size, or do you mean that injector size would be used to determine injector pulse width further down the line? 4. Could the author please reply to me in person as this is my first post and I want to know it got there. Mike Woodd (wooddm@xxx.nz) ------------------------------ From: "Grigoris Dimitriadis" Date: Mon, 15 Jul 1996 00:53:35 +0300 (EET) Subject: Re: GMP4 ECM '89 HELP?!? What is your email ??? ------------------------------ From: "Woodd, Michael" Date: Mon, 15 Jul 1996 08:57:00 +1200 Subject: RE: DIY_EFI Digest V1 #197 >From: ws6transam@xxx.net (Daniel R Burk) >Date: Fri, 12 Jul 1996 22:18:37 -0400 (EDT) >Subject: Re: Build your own 5th wheel update > >Well, I have my 5th wheel working on my bench at the lab. Here's the system >as it stands: >The 5th wheel consists of a 26 inch bicycle rim mounted on a cast-off >mountain bike fork. The wheel has been modified with aluminum tape with a >that I've read in the lab. I'm shooting for 91 MPH with the Trans Am. > > -- Dan. Dan, good luck - I hope that your bicycle wheel is well balanced though, 91MPH is a bit out of the normal operational envelope for a bicycle... Mike Woodd (wooddm@xxx.nz) ------------------------------ From: peter paul fenske Date: Sun, 14 Jul 1996 15:24:10 -0700 Subject: Re: oil control >Application is SBC with high volume oil pump which delivers about 90 PSI >cold. Oil supply lines are #4AN and drains are #6AN back to top of oil pan >just below the block. I'm having trouble believing that BOTH units could >have been assembled improperly. Is the oil seal a mechanical unit or does >it have some sort of "packing gland" that can be replaced? Could I have >damaged it by excessive pressure, or could I just turn down the pressure and >hopefully solve the problem? I've never read anywhere that too much oil >(pressure) is bad for these things. > >Thanks in advance for any help you might provide..... > > > Bill > >Hi Bill >Don't have too much to help you. However I think while a buick would >appreciate 90PSI this is too much for a chev. 10 PSI per 1000 RPM >is the oft Smokey quoted figure and I believe high oil pressures >would aggravate your leakage problems. When in doubt go to high >volume not high pressure with a SBC. Run a separate filter for >the turbos and consider a Harrison oil cooler since it sounds >like you have quite a shack there. >Well thats about 3 sense. Hope someone can help you more >GL: peter >Ps the challenge series race cars often ran with three quarts of >oil and low pressure max 45 PSI and engines usually ran >the full racing season. > ------------------------------ From: Dave Zug Date: Sun, 14 Jul 1996 19:41:07 -0400 Subject: Re: GMP4 ECM '89 HELP?!? Grigoris Dimitriadis wrote: > > What is your email ???doesn't it come thru with the message? its dzug@xxx.us and i'm downloading xferpro right now to do UUE i assume your on line right now i know where we can go to talk live can you TELNET? ------------------------------ From: "Charlie North @xxx.net> Date: Sun, 14 Jul 1996 20:06:33 -0400 Subject: Re: oil control Howdy William On all the Installations I have done I use -10 return lines. Try putting a pressure gauge on the -6 return at the turbo, if you see more than a few pounds, go to a larger drain line. Charlie- At 04:35 PM 7/14/96 -0700, you wrote: >Hey all you turbo gurus...... > >Anybody have trouble containing oil in the turbos? I have a setup with 2 >brand-new turbos that leak oil badly into the hot section causing great >billows of blue smoke. >Application is SBC with high volume oil pump which delivers about 90 PSI >cold. Oil supply lines are #4AN and drains are #6AN back to top of oil pan >just below the block. I'm having trouble believing that BOTH units could >have been assembled improperly. Is the oil seal a mechanical unit or does >it have some sort of "packing gland" that can be replaced? Could I have >damaged it by excessive pressure, or could I just turn down the pressure and >hopefully solve the problem? I've never read anywhere that too much oil >(pressure) is bad for these things. > >Thanks in advance for any help you might provide..... > > > Bill > > > ------------------------------ From: Land Shark Date: Sun, 14 Jul 1996 19:03:26 -0600 Subject: Re: RE: EFI At 08:41 7/15/96 +1200, you wrote: >1. How exactly would the controller calculate "load" from "air" and "rpm" >and "a constant"? i.e. what would the equation be? (please treat me as >completely ignorant, though I am not quite) > >(I assume "load" refers to the air volume passing into the engine) Ahh .. glad you asked... :) Consider LOAD to be equal to .. AIR INDUCTED per CYCLE of the motor .. The LOAD as Tl (Tee sub ell) is ... Tl=Q/(n*Ki) where Q is that airmass or airmass approx from airFLOW in Kg/Hr.. n is engine speed in RPM Ki is the injector constant that equates Tl to the base injector pulse width needed for that flowrate of injector and that amount of air/cylinder.. >2. How would you work out what this constant is? Mathematically from injector flowrate and AFR of 14.7:1... >3. Also, I am confused as to why the calculation of load would depend on a >constant upon injector size, or do you mean that injector size would be used >to determine injector pulse width further down the line? Because in a BOSCH system LOAD is actually a TIME .. TEE sub ell .. the THEORETICAL injector open time needed on Engine X, with Injector Y .. under those exact conditions of measured airmass/speed to reach Lambda=1 with a theoretical Voll Eff. of 1... Jim ------------------------------ From: Roger Enns Date: Sun, 14 Jul 1996 21:54:34 -0400 (EDT) Subject: Re: oil control Hi William, I would suggest switching to #10 return (5/8") minimum. Any restriction whatsoever will cause leakage through the labyrinth seal behind the turbine. Also ensure that your return to sump is as vertical as possible, and returns above the oil level in the sump at all times. These items are critical as the return oil is whipped into a foam as it passes the bearing, and needs an unobstructed path to flow properly. Good luck, Roger Enns (renns@xxx.com) On Sun, 14 Jul 1996, William A. Sarkozy wrote: > Anybody have trouble containing oil in the turbos? I have a setup with 2 > brand-new turbos that leak oil badly into the hot section causing great > billows of blue smoke. > Application is SBC with high volume oil pump which delivers about 90 PSI > cold. Oil supply lines are #4AN and drains are #6AN back to top of oil pan > just below the block. I'm having trouble believing that BOTH units could > have been assembled improperly. Is the oil seal a mechanical unit or does > it have some sort of "packing gland" that can be replaced? Could I have > damaged it by excessive pressure, or could I just turn down the pressure and > hopefully solve the problem? I've never read anywhere that too much oil > (pressure) is bad for these things. > > Thanks in advance for any help you might provide..... > > > Bill > > ------------------------------ From: "Woodd, Michael" Date: Mon, 15 Jul 1996 14:59:00 +1200 Subject: Re: RE: EFI > From: Land Shark >>1. How exactly would the controller calculate "load" from "air" and "rpm" >>and "a constant"? i.e. what would the equation be? (please treat me as >>completely ignorant, though I am not quite) >> > > Ahh .. glad you asked... :) Me too ;-) > > Consider LOAD to be equal to .. AIR INDUCTED per CYCLE of the motor .. > The LOAD as Tl (Tee sub ell) is ... > Tl=Q/(n*Ki) where Q is that airmass or airmass approx from airFLOW in Kg/Hr.. > n is engine speed in RPM > Ki is the injector constant that equates Tl to the base injector > pulse width needed for that flowrate of injector and that amount > of air/cylinder.. Soooo, it comes down to airmass, as it always must - What I am really wondering then is how you work out the "airFLOW" in Manifold Air Pressure EFI systems, to then work out the "airMASS"... Mike Woodd (wooddm@xxx.nz) ------------------------------ From: Land Shark Date: Sun, 14 Jul 1996 22:59:46 -0600 Subject: Re: RE: EFI At 14:59 7/15/96 +1200, you wrote: >Soooo, it comes down to airmass, as it always must - What I am really >wondering then is how you work out the "airFLOW" in Manifold Air Pressure >EFI systems, to then work out the "airMASS"... MAP systems work differently .. from MAP and MAT and VE you can determine how much air per cycle is inducted (calculated NOT measured, some bit of error) and do the fuel that way .. the Equation is in Heywood, I think and if not Heywood, then the Automotive Electronics book (new one) Jim ------------------------------ From: Alexander.M.Lichstein@xxx. Lichstein) Date: 15 Jul 96 02:11:56 EDT Subject: Re: RE: EFI Roughly speaking, you must know VE at all engine speeds. Let's assume 100% VE (that is, that every cylinder is able to completely fill itself with air attaining equilibrium with the air outside the valve.) This means that by PV=nRT we can determine that (for example), with 150cc cylinders, and a wide open throttle with perfect manifold design, we will have: P = 1atm V = 150cc R = constant T = measured (293K) then we can get n (moles or # of molecules) which with a bit of plugging will tell us mass. In reality, the VE is not constant (f(RPM)) and is not 100%. In that case, we can adjust our calculation on the left hand side since the air will not necessarily be at the same pressure as that outside the port. If you close the throttle, then the pressure in the manifold will drop accordingly. We plug this new value for pressure at the ports into the above equation (adjusted for VE) and voila... air mass. I haven't done the conversions above and I'm mixing my units, but you get the idea. - - Z ------------------------------ From: walter.kaufmann@xxx.ch (Walter Kaufmann) Date: Mon, 15 Jul 1996 09:23:06 +0200 Subject: ignition coil? question about the new two spark coil: Is the direction of the ignition current changed or not for the spark? (neg voltage for the left zylinder (ignition) pos for the right, the change and neg voltage for the right zylinder and pos for the left (non working)) Thanks Walter ------------------------------ End of DIY_EFI Digest V1 #198 ***************************** 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".