DIY_EFI Digest Friday, 9 February 1996 Volume 01 : Number 037 In this issue: Re: MAF Sensors and Re:Spell Check Re: True dual exhaust and O2 Sensors Re: True dual exhaust and O2 Sensors Sequential Setup? Air Sensors EFI system DIY_EFI Vendor List - Revised RE: re: Re: Sensor Questions? Re: Sequential Setup? Re: Spellcheckers Re: GM TPI system Electronics suppliers RE: DIY_EFI Vendor List - Revised Re: True dual exhaust and O2 Sensors Re: Sequential Setup? EFI vs. Carb Re: Electronics suppliers RE: DIY_EFI Vendor List - Revised Re: Electronics suppliers Exhaust Gas Analysers ? RE: re: Re: Sensor Questions? Multiprocessor system Re: Exhaust Gas Analysers ? Re: Multiprocessor system See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Mark Boxsell Date: Thu, 8 Feb 96 23:16:13 +1100 (EST) Subject: Re: MAF Sensors and Re:Spell Check At 10:46 AM 7/02/96 EST, you wrote: >Alain Marchildon wrote: > >>OK >>The bickering has went on long enough. >>I will reply be my self. >>And terminate it my self. > >Time to throw my 2 cents in - >As a third generation American of French Canadian decent, give the guy a break! > >Alain, c'est ne pas votre probleme, ca va? :-{)> > >Sometimes *I* write worse in English. Maybe it's in our genes. > > >Getting back to DIY_EFI, does anyone have more information, including the >governing equations on hot-wire mass air flow sensors - I may have to work one >up for my Briggs & Stratton project. Single cylinder engines (especially >leaky flatheads like the B&S) have a horrible (to non-existent) vacuum signal >to work with, and I'm not likely to find a MAF sensor with a 1" throat at my >Ford dealer. Since the system I'm designing needs to be altitude sensitive, a >MAF may be a better approach. The original plan was to use MAP and gather data >on the test stand, but time is getting short and a MAF interfaced to a lookup >table may be a far better choice than a MAP that may be reading noise. > >I'm assuming that the MAF hot wire is fed with a constant current and the >voltage variation due to temperature-dependent change of resistance is the >output that is conditioned further. If anyone has any more info it would be >much appreciated. > > >MAP - Manifold Absolute Pressure >MAF - Mass Air Flow >B&S - Briggs & Stratton, maker of most of the world's lawn mower engines. > > >Cliff Ducharme > / >"A wing and a prayer" _______[*]_______ > b / d > > >My remarks do not reflect the opinions of my employer. > Cliff, use throttle position it will work fine. You will still have to "map" throttle position verses RPM of course. For altitude use a map sensor (eg GM style) (don't connect to the manifold, don't even use a hose on it) and apply a separate correction after you have looked up the value in the "map". Using a Briggs & Stratton is a bit of a worry we use those things for boat anchors in Australia (although I must conceed that their newer engines are much better). Why not a nice Honda or Mitsubishi stationary engine. You are wasting your time with MAF on a single cylinder engine because of the pulsing in the inlet. I have heard a lot of talk (on this list) about MAF sensors but until you have to apply them they sound easy however you have all sorts of problems with pulsing and reverse flow, etc. Why do you think some of the manufacturers have such elaborate ducting and air cleaners (air box) that look like they came off the space shuttle! Don't get me wrong I have nothing against MAF but it's the same old story things are not as easy as they may first appear. This reminds me of a guy who had an early Air Sensors system (this was about 7 years ago)on a Mitsubishi Starion Group A car and wondered why the thing would go bulk rich on gear changes and blow a puff of smoke and carry on when he put his foot down again. The Air Sensors system (which uses MAF) was happily injecting the correct amount of fuel for all the air that was going out the compressor bypass valve!!!! A word for Peter Wales. I been told we don't use the "Queen's english" down under but everyone seems to understand what I'm saying! regards, Mark Boxsell MRB Design Sydney Australia ------------------------------ From: "Brian Warburton, c/o Turbo Systems Ltd" Date: Thu, 08 Feb 1996 14:39:25 Subject: Re: True dual exhaust and O2 Sensors >Hello > >I'm exploring the possibility of changing from single to true dual exhaust on >my late model Ford truck which appears to have the EEIV and MAF sensor >(California). Do I need to install a second O2 sensor? Would this sensor be >connected parallel to the original or does the EEIV have an input for a >second sensor? I think many (most?) late model mustangs had true dual exhaust >and the controllers are similar I would guess. > Although there is a possibility that the module hardware may support dual HEGO's, I would imagine that the second HEGO option will have been turned off in the software to avoid spurious self-test error codes. Unless you're an EEC-iv hacker, you may have a problem re-enabling it ....... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Brian Warburton, "Still searching for the perfect curve....." email: bwarb@xxx.net Advanced Automotive Electronics Ltd, Van-Nuys House, Scotlands Drive, Farnham Common, England. SL2-3ES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ------------------------------ From: "Brian Warburton, c/o Turbo Systems Ltd" Date: Thu, 08 Feb 1996 14:39:25 Subject: Re: True dual exhaust and O2 Sensors >Hello > >I'm exploring the possibility of changing from single to true dual exhaust on >my late model Ford truck which appears to have the EEIV and MAF sensor >(California). Do I need to install a second O2 sensor? Would this sensor be >connected parallel to the original or does the EEIV have an input for a >second sensor? I think many (most?) late model mustangs had true dual exhaust >and the controllers are similar I would guess. > Although there is a possibility that the module hardware may support dual HEGO's, I would imagine that the second HEGO option will have been turned off in the software to avoid spurious self-test error codes. Unless you're an EEC-iv hacker, you may have a problem re-enabling it ....... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Brian Warburton, "Still searching for the perfect curve....." email: bwarb@xxx.net Advanced Automotive Electronics Ltd, Van-Nuys House, Scotlands Drive, Farnham Common, England. SL2-3ES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ------------------------------ From: Philip Barrie Date: Fri, 9 Feb 1996 06:47:01 +1100 (EST) Subject: Sequential Setup? Dear Sirs, I wuold like to know your veiws on the "ideal" set-up for a sequential f/i system. Namely the best "on time" in relation to valve duration and at what point should the injector be timed to start it's operation? Also is there advantages to be had by altering the valve timing for a sequentail system as opposed to synchronous? Any input would be greatly appreciated ! Thanking You, Philip pbarrie@xxx.au ------------------------------ From: "Zublin, Bryan (SD-MS)" Date: Thu, 08 Feb 1996 13:16:00 -0800 (PST) Subject: Air Sensors EFI system >This reminds me of a guy who had an early Air Sensors system (this was about >7 years ago)on a Mitsubishi Starion Group A car and wondered why the thing Does anybody know if the Air Sensors system is still available? I remember hearing about it some years ago. Any address? Bryan Zublin bzublin@xxx.com ------------------------------ From: orin@xxx. Harding) Date: Thu, 08 Feb 1996 16:39:14 -0500 Subject: DIY_EFI Vendor List - Revised Revised #10 systems info. After Market DIY_EFI Systems: (BASE system prices shown. Usually doesn't include sensors) 1. Electromotive, Inc. 14004-J Willard Road Chantilly, VA. 22021 (703) 378-2444 All prices ECU only a. HPV-1 Direct fire, Distributorless Ignition US$439 (4 Cyl) UD$459 (6 Cyl) US$499 (8 Cyl) b. HPV-3B " " " " US$664 (4 Cyl) US$689 (6 Cyl) US$724 (8 Cyl) c. TEC-I Engine Management (Fuel&Ign Mgt.) US$1,500 (6 Cyl) US$1,550 (12 Cyl) d. TEC-II " " " " " US$999 (4 Cyl) US$1,029 (6 Cyl) US$1,069 (8 Cyl) e. Software for the above US$150 - US$550 2. Haltech (Australia) US Distributor Performance Automotive Electronics 2158 W. Northwest Highway, Suite 400 Dallas, TX 75220 (214) 831-9800 All prices ECU only a. IG4 Ignition Control US$480 b. F7B EFI system US$640 c. F7C EFI system US$680 d. F9 EFI system US$680 e. E6 EFI system US$960 2a. EFI (Haltech) Unit 7 130 Taren Point Road Taren Point 2229 Sydney Australia 3. Mr. Gasket 8700 Brookpark Rd. Cleveland, OH 44129 (216) 398-8300 Contact Mark Hamel (X488) 3a. ACCEL - Same address and phone 3b. Digital Fuel Injection (DFI)- Owned by Mr. Gasket 37732 Hills Tech Dr. Farmington Hills, MI 48024 a. 74040A Universal US$740 b. 74022L (Chev 350) US$900 c. Calmap software US$185 4. Emtech (Australia) 5. NOS/EFI Tech. 6. Holley 11955 E. Nine Mile Road Warren, MI 48089-2003 a. Pro-Jection US$600 - 1,000 7. Racetech Engineering Bay G 1007 55th Ave.,NE Calgary, Canada T2E 6W1 a. SDS (Simple Digital Systems) EM-1 8. Advanced Automotive Electronics Ltd. Van Nuys House Scotlands Dr. Farnham Common Slough SL2-3ES England Phone: 01753-642019 Contact Brian Warburton email: bwarb@xxx.net a. Ignition Management System UK#395 b. Clubmans EFI system UK#495 c. Engine Management System (Ign & EFI) UK#755 d. Programming software - free with purchase 9. Plus 1 Micro, Inc. PO Box 1781 Lawrenceville, GA 30246-1781 a. InterACQ 10. Advanced Engine Management (Australia) 22 Melrich Rd. Bayswater, Victoria Australia Phone: (+613) 9761 3161 fax: (+613) 9761 3162 email steve@xxx.au Prices include basic wiring loom & sensors with no PC required. Supports rotary, 4, 6, & 8 cylinder engines. a. Wolf2D EFI with built in user I/O US$660 b. Wold3D EFI+IGN with detachable user I/O US$1030 Manufacturer #1 #2 #3 Model TEC II E6 74040A PC I/O yes yes yes Prog. offline yes yes no Inj. drivers 2 8 4 Additional drivers yes($) Seq. Inj. yes($) no yes($) Fuel Map yes yes yes # fuel maps by RPM 8 16 Prog. points/RPM 8 8 Total prog. points 64 256 Warm-up Map yes yes yes Idle control yes(GM ICM) no yes(GM ICM) Data logging yes($) yes yes Speed density yes yes yes Mass Air Flow yes($) no no EGO - Closed loop yes yes yes Gen. purpose output yes yes Ignition control yes yes yes Ign. amp. needed no yes yes Ign. map points 64 yes Detonation sensor yes no yes Manufacturer #6 #7 Model Projection SDS PC I/O no no Prog. offline no Inj. drivers Additional drivers Seq. Inj. Fuel Map # fuel maps by RPM Prog. points/RPM Total prog. points Warm-up Map Idle control Data logging Speed density Mass Air Flow EGO - Closed loop Gen. purpose output Ignition control Ign. amp. needed Ign. map points Detonation sensor Manufacturer #8 #8 #8 Model Ign. Mgt. Clubmans Eng. Mgt. Sys. PC I/O yes yes yes Prog. offline Inj. drivers n/a 1 4 Additional drivers n/a yes (+#) yes (+#) Seq. Inj. n/a no yes Fuel Map n/a yes yes # fuel maps by RPM n/a 16 16 Prog. points/RPM n/a 24 24 Total prog. points n/a 384 384 Warm-up Map n/a Idle control n/a yes (?) Data logging yes yes yes Speed density n/a yes yes Mass Air Flow n/a EGO - Closed loop n/a no yes Gen. purpose output Ignition control yes yes yes Ign. amp. needed no no no Ign. map points 384 384 384 Detonation sensor no no yes Manufacturer #10 #10 Model Wolf2D Wold3D PC I/O no no Both have an LCD/keypad I/O Prog. offline yes yes Inj. drivers 5 5 Current limited Additional drivers 3 3 Seq. Inj. no no 2 bank Fuel Map yes yes # fuel maps by RPM 8 8 Prog. points/RPM 16 16 Total prog. points 128 128 Warm-up Map yes yes Idle control no no Data logging no no Speed density yes yes Mass Air Flow yes yes EGO - Closed loop no no can display EGO bargraph Gen. purpose output no no Ignition control no yes Ign. amp. needed n/a yes Ign. map points n/a ? Detonation sensor no no Orin Harding - Greensboro, NC ('74 MGB-GT - '79 MGB Roadster with Electromotive TEC II) ------------------------------ From: ehernan3@xxx.com (Edward Hernandez (R)) Date: Thu, 8 Feb 1996 16:53:50 +0500 Subject: RE: re: Re: Sensor Questions? "Hitachi later developed a MAF that measures a portion of the entire air flow ("bypass type"). The advantages include less dirt build up and damage immunity from intake backfiring. A disadvantage is that the reverse air flow is not measured, so if there is a lot of pulsation at the meter, it will cause errors (?)." Not necessarily. The hot-wire principle does not account for which direction air is flowing, so if if air goes in, then some flows back out, it will measure both flows. This is a far larger error than measuring only what went in. "Quick question: what exactly is going to cause this sudden increase in the amount of required air that is going to draw a vacuum?" Let me explain the crux of the problem: if the MAF sensor is located upstream of the throttle body, there will always be a delay during throttle transients. Air is compliant, like a spring. As an extreme but common example, when you go to WOT it takes time for the manifold to fill with air at atmospheric pressure because it was at some level of vacuum just prior to throttle opening. On top of that, the engine is always "draining" the manifold. By the time the MAF sensor "sees" this demand for air fill the manifold(and asked the ECU to provide more fuel), the engine has consumed enough air(and sped up) to cause a lean stumble. The closer the MAF sensor is to the throttle plate(s), the faster its response. However, some of you have correctly pointed out the risk of the MAF sensor picking up intake pulsations as you place it close to the inlet valves. "Just remember that a MAF system also has to be calibrated to the engine it is on. The MAF give out a voltage (or frequency) depending on how much air is going through it. It does not tell you "currently, there is x Kg/sec flowing through me". MAF sensors need to be calibrated for completely different reasons than do SD systems. MAF sensors need to be calibrated primarily to the airbox they are fitted to in order to learn their transfer function. That transfer function is what converts voltage(or frequency) to kg/hr of air. This has nothing to do with the engine they are fitted to. The airbox determines the flow field in the MAF sensor, which is particulary critical to the transfer function of bypass MAF sensors. "Full field" sensors(like Bosch) are less sensitive, but they do have flow straighteners to help them be a bit more robust at the cost of some flow capacity. It is the acceleration enrichment which must be calibrated to the engine due to throttle transients, and those transients depends greatly on the intake manifold itself, the engine displacement, cam events, and MAF sensor location. This is one parameter that is easily(amd safely) tuned by seat of the pants, and is also why the Mustang magazine car had problems. Someone asked if MAF sensor placement on turbo engine affects thei measurement because the pressure and temperature is different after the compressor. All air must pass through the MAF whether or not its density changes downstream , so placement is a matter of response time, not accuracy. ------------------------------ From: walter@xxx.com (thomas walter x5955) Date: Thu, 8 Feb 96 15:40:47 CST Subject: Re: Sequential Setup? Phillip, There has been some discussion on this list regarding the subject of sequential vs. a 'batch' method of firing the fuel injectors. You may find some material by using the majordomo server to obtain the archeived messages. (send mail to majordomo@xxx.edu with just the word 'help' in the body of the message) At WOT (Wide Open Throttle) a properly sized fuel injector will be on almost 90% of the time, so there is little difference between sequential or batch methods. At idle and partial throttle is where you would expect the largest gains in performanace/economy. I have heard figures ranging from 2% to 10% improvements by properly timing the injection on sequential injections. For sequential injection, most common method, is to time the injector to CLOSE with the closing of the intake valve. Would be an interesting experiment to use an engine dyno and modify the software to test these various parameters to see which method produces the best results. I know of one engineer who was startled by the difference when they optomized the timing of a sequential fuel injection system. I just want to get my running! :-) Cheers, Tom "who needs a proof reader" Walter Austin, TX. ------------------------------ From: "Jim Staff" Date: Thu, 8 Feb 1996 22:06:22 GMT Subject: Re: Spellcheckers In message <199602070049.TAA20525@xxx.net> writes: > > > >It's time for the flaming about spell checking, grammar checking, > >etc. to stop. Do Any of you realize 1 of 3 things... 1. This is a DIY_EFI Mail serve, not an english masters free for all? 2. Do you realize how pointless these flames are because no one gives a rat's behind what you who obviously must be the master of everything has to say. 3. Lastly if anyone really cares it's you little group of english bangers. For real users it just trash that you have to delete. For the server owner it's wasted space. And for people that you're picking on it will show them how anal you are. No offence but ain't it the truth everyone? ------------------------------ From: "Jim Staff" Date: Thu, 8 Feb 1996 22:11:05 GMT Subject: Re: GM TPI system > If you are electronically-inclined, you can make a fuel injector > energizer with a 555 timer and a driver transistor (I made one > from a basic Stamp). If not, you can get the energizer device > from J.C.Whitneys. Do you have a schematic for a 555 timer based EFI? I think it would be a great system to compare against the PC based one I'm working on. Thanks, Jim Staff ------------------------------ From: "Jim Staff" Date: Thu, 8 Feb 1996 22:19:08 GMT Subject: Electronics suppliers What are good places to get electronics stuff? Could you provide me with the names, number, and costs of catalogs plus you personal thoughts on them. I know about digi-key : I've had good experiences with them. But they are a little expensive and don't carry a few things I like (Such as mos-fets and bipolar transistors) Also the have some strange love of national semiconductor. Which is a good company and provides good parts. Archer [Radio shack] : They've got thier good and bad points. They are a tad bit more expensive. And the selection is limited. But after all they are just a few blocks away [1 mile in my case] so you have instant satisfaction. Also they have a knack to have the IC's I need but never the resistors or capacitors I need. They have more diodes than I've ever seen and have never heard of some of the ones they have. If anyone know about a company called ____***ARROW***____ please give me information. They are a good supplier and carry buttloads of stuff. Bye, Jim Staff ------------------------------ From: "Zublin, Bryan (SD-MS)" Date: Thu, 08 Feb 1996 15:52:00 -0800 (PST) Subject: RE: DIY_EFI Vendor List - Revised How about adding vendors that are no longer in business, for historical purposes. For example (quoting neville, neville@xxx.com) regarding the Air Sensors system: "i don't think they are still around. i have a system built by Dennis Watkins, who was their lead engineer. He built it after he left, and it looks/works exactly like an Air Sensors system. i purchased it to use on a 1.3L Fiat, but it seemed like it was still calibrated for a big V8. In order to drive it, i had to just steer and brake while my friend in the passenger seat turned the base mixture adjustment in lieu of the throttle! The harness is only set up for 4 injectors, but i'm sure the box will drive 8. When Dennis decided to move on to something else, i got schematics from him. Fred Miranda looked it over, thinking he might buy it from me, prior to implementing his Electromotove system." Bryan Zublin bzublin@xxx.com - ------------------------------ From: jwharris@xxx. Harris) Date: Thu, 8 Feb 96 18:46 EST Subject: Re: True dual exhaust and O2 Sensors Do I need to install a second O2 sensor? Would this sensor be >>connected parallel to the original or does the EEIV have an input for a >>second sensor? If I were trying to do this I'd do electronically what the single sensor does on the vehicle - average the singals. Use a low input current op anp to sum the inputs and divide the result by two. The circuit needs to have high input impedance (~2 meg.) and the output must be divided by two (gain of .5 with precision resistors) I'm not sure exactly what this would do the O2 diagnostic when its cold. Ours applay a .45 volt bias to the sensor. When it heats up, the impednace of the sensor drops, overriding the bias. You should be able to run the thing from a single supply but use an op amp and circuitry designed to opeate from a single supply with low input voltages. I forget the name of the parameter of interest. - ---------------------------------------------------------------------------- J.W. Harris Delco Electronics Corp. Project Engineer One Corporate Center Powertrain Electronics M.S. CT40C Kokomo, IN 46904-9005 jwharris@xxx.com jwharris@xxx.com Of course, all responses are my own and should not be mistaken for those of Delco Electronics or General Motors. ------------------------------ From: pjwales@xxx.net (Peter Wales) Date: Thu, 08 Feb 1996 21:58:28 -0500 Subject: Re: Sequential Setup? At 03:40 PM 2/8/96 CST, Tom wrote: >At idle and partial throttle is where you would expect the >largest gains in performanace/economy. I have heard figures >ranging from 2% to 10% improvements by properly timing >the injection on sequential injections. We did a lot of tests on the dyno on exactly this and found NO improvement in power. The reason is simple, you need air, and fuel to burn in it, and if you have the right amounts of each you will get the most power. The economy was another matter altogether. By timing the injection so that there is the minimum time for the fuel/air mixture to sit in the inlet you got the most economy. This is because the droplets coalesce and form larger droplets, which take longer to burn. Hence you need more of them to get all of the air used and thus economy suffers. I was given the parallel of the droplets being like onions, you need to burn off each layer until they are all gone, the bigger the droplet the more layers. >For sequential injection, most common method, is to time >the injector to CLOSE with the closing of the intake >valve. Exactly Peter Wales President Superchips Inc Chairman Superchips Ltd "Timing is everything" Superchips home page with all the answers http://www.superchips.com ------------------------------ From: MTaylorfi@xxx.com Date: Thu, 8 Feb 1996 21:08:53 -0500 Subject: EFI vs. Carb Hey there, Car Craft did an EFI vs. carb engine. They were about equal in running (hp & torque), but the TPI, I think, had a little more at the top end. Now, try to stick some carbs on a twin turbocharged and intercooled V8 and do a comparison. I rest my case! See ya, Mike ------------------------------ From: dn Date: Thu, 8 Feb 96 20:00:26 MDT Subject: Re: Electronics suppliers > What are good places to get electronics stuff? Could you provide me with > the names, numbers, and costs of catalogs plus your personal thoughts on > them. Read on... > Archer [Radio shack] : They've got thier good and bad points. Mostly bad. In general, stay away unless you need something at 4:30 on a saturday afternoon... > If anyone knows about a company called ____***ARROW***____ please give me > information. They are a good supplier and carry buttloads of stuff. Arrow is a huge supplier, but generally they don't like to talk to you unless you want to buy large quantites. Their policy is not to accept orders of less than $100 PER ITEM. Ie, you have to buy $100 worth of a single part number. Future/Active Electronics is a good supplier, Future is the industrial (read "quantity") arm, and Active have stores where they sell just about everything in small quantities, bagged and priced accordingly. Like Radio Shack, but no consumer goods (stereos, etc.) and with 1000 times the variety. Active is probably your best bet, they should have a store in most larger cities, and have damn near everything you could want in stock. All I know about their US operation is that they have head office in Boston. Newark Electronics is another large supplier, but again, they are geared to industrial customers, but will sell small quantities, prices are a bit steep, but not too bad. Their catalog has everything including the kitchen sink, (over 1500 pages) and is available free @ 1-800-463-9275 Hamilton Hallmark is another supplier who stocks a lot of parts. America II Electronics specialize in microprocessor related stuff. I could go on with more, but you're better off to do a little research on your own. I'm up in Canada, so I don't have American addresses and phone numbers for most of these places, but you can look them up in the Thomas Registry at your local library. Another good source is any electronics hobbyist magazine, such as Popular Electronics which have zillions of ads for mail order and surplus houses in the back. Most of these companies will send you a catalog for free, just ask... regards dn - -- - --------------------------------------------------------------------- Darrell A. Norquay Internet: dn@xxx.ca Datalog Technology Inc. Bang: calgary!debug!dlogtech!darrell Calgary, Alberta, Canada Voice: +1 (403) 243-2220 Fax: +1 (403) 243-2872 @ + < __/ "Absolutum Obsoletum" - If it works, it's obsolete -------------------------------------------------------------------- ------------------------------ From: orin@xxx. Harding) Date: Thu, 08 Feb 1996 22:22:00 -0500 Subject: RE: DIY_EFI Vendor List - Revised > >How about adding vendors that are no longer in business, for historical >purposes. > Bryan.. Sounds like a good project so why don't you keep that list up...I'll keep up the current list and with you keeping the "out of business" list going, we'll have all the bases covered.. Cheers Orin Harding - Greensboro, NC ('74 MGB-GT - '79 MGB Roadster with Electromotive TEC II) ------------------------------ From: tom sparks Date: Thu, 8 Feb 1996 23:51:54 -0600 Subject: Re: Electronics suppliers >I could go on with more, but you're better off to do a little research >on your own. I'm up in Canada, so I don't have American addresses >and phone numbers for most of these places, but you can look them up >in the Thomas Registry at your local library. Another good source... Thomas Registry is online at: http://www.thomasregister.com:8000/finder/gate1.html VERY handy. Best regards, Thomas Sparks ------------------------------ From: Angus Mackinnon Date: Fri, 9 Feb 1996 17:21:48 +1100 (EST) Subject: Exhaust Gas Analysers ? Something slightly off the topic to waste some bandwidth.... I am in the market ( depending on price :-)) for Exhaust gas analyser that is capable of giving readings for CO, O2, HC and NOx. I am after people's opinions in regard to brands, quality and pricing. Names of distributors or manufacturers would also be appreciated. Thanks, Angus angus@xxx.au P.S. As I'm from Australia, English is my second language. Please excuse any grammatical errors. :-). ------------------------------ From: Fred Miranda Date: Thu, 8 Feb 1996 22:23:16 GMT Subject: RE: re: Re: Sensor Questions? >Let me explain the crux of the problem: if the MAF sensor is located >upstream of the throttle body, there will always be a delay during >throttle transients. Air is compliant, like a spring. As an extreme >but common example, when you go to WOT it takes time for the manifold >to fill with air at atmospheric pressure because it was at some level >of vacuum just prior to throttle opening. On top of that, the engine >is always "draining" the manifold. By the time the MAF sensor "sees" >this demand for air fill the manifold(and asked the ECU to provide >more fuel), the engine has consumed enough air(and sped up) to cause a >lean stumble. correct me if I'm wrong. when you go from hi vac to WOT, the only air to enter the cylinders is previously measured air between the throttle and the MAF and air passing through the MAF. So the only error would be in not measuring that volume between T-body and MAF. Unless the distance is large I don't see it as a problem. In my limited experience in tuning with MAF (1 car, switched from speed density to MAF) I found the required acceleration enrichments dropped and the general drivability improved. Fred ------------------------------ From: "Clinton L. Corbin" Date: Thu, 8 Feb 96 23:42:50 PST Subject: Multiprocessor system I have been thinking about a fuel injection system composed of four 68HC11 microprocessors. The first processor would run the ignition system. It would have inputs from crank and cam sensors (no missing tooth in the crank senor for syncronization) and from the map sensor. It would also receive 6 bits of data from the master controller and 4 bits of control information. There would be two seperate (and identical) fuel injection systems. Each would control 4 fuel injectors. For a 12 cylinder engine, one more fuel injection subsystem could be added without change to the master controller. The only change would be in which crank trigger pulse was the "first" pulse for it. All of these subsystems would receive 6 bits of data and 4 bits of control information from the master controller. All of the fuel injection systems would receive the same data, but it would be different (of course) than the data system for the ignition module. These modules would be fed data directly from the various inputs that they need to calculate the correct amount of fuel. The master controller would cordinate everything for the other modules. It would receive data from the cam position sensor (it needs to know how fast the engine is running and if it is running at all), the knock sensor, temperature, oil pressure, and others. It would not be directly controlling either the ignition or the fuel injection. Those modules run on there own. It would be able to tell the ignition system to advance or retard the timing a number of degrees through the data and control information. It would also tell the ignition system if it should run or not. It interfaces with the fuel injection modules in much the same way. It tells then when to run, and it can tell it to richen or lean the mixture by a certain percentage. If the master controller tells it to lean out the mixture outside of the boundaries for the mixture, the fuel injection controlers can set an error flag and keep running rich. Blubbering rich being preferable to "piston melting" lean any day. This system would not use any type of data bus. Do to the small about of data going to the sub modules (and data does not go to the master controller from the sub modules), there is no need for a data bus. Also, each controller runs its own program and deals with learning on its own. One problem with this idea is that to change all of the programs (say to redefine the data), you would have to pull all 4 eeproms. Truthfully, this I can live with. Another advantage is that you could build and test the ignition system before you had to make the rest of the system. This would at least let you know that your timing information from the cam and crank senors was as you predicted. Also, there is no shortages of input capture and output compare ports. One question I do have how should I buffer the various signals that need to go to multiple modules? Would I have to? Would the standard input filtering be enough of a buffer to feed up to 4 inputs simultainiously? I would love to here everyones ideas and opinions on this idea. I do beleive I will be looking into it somemore. And if this idea was brought up in the past and well and throughly shot down, I appologize for bringing it up again. Thanks for you input. Clint ccorbin@xxx.com ------------------------------ From: arthurok@xxx.com (ARTHUR OKUN ) Date: Thu, 8 Feb 1996 23:49:22 -0800 Subject: Re: Exhaust Gas Analysers ? You wrote: > >Something slightly off the topic to waste some bandwidth.... > >I am in the market ( depending on price :-)) for Exhaust gas analyser >that is capable of giving readings for CO, O2, HC and NOx. > >I am after people's opinions in regard to brands, quality and >pricing. Names of distributors or manufacturers would also be >appreciated. > > >Thanks, > >Angus > >angus@xxx.au > >P.S. As I'm from Australia, English is my second language. >Please excuse any grammatical errors. :-). > you mean american english . ------------------------------ From: arthurok@xxx.com (ARTHUR OKUN ) Date: Fri, 9 Feb 1996 01:05:37 -0800 Subject: Re: Multiprocessor system You wrote: > >I have been thinking about a fuel injection system composed of four 68HC11 >microprocessors. The first processor would run the ignition system. It >would have inputs from crank and cam sensors (no missing tooth in the crank >senor for syncronization) and from the map sensor. It would also receive >6 bits of data from the master controller and 4 bits of control information. > >There would be two seperate (and identical) fuel injection systems. Each >would control 4 fuel injectors. For a 12 cylinder engine, one more fuel >injection subsystem could be added without change to the master controller. >The only change would be in which crank trigger pulse was the "first" pulse >for it. All of these subsystems would receive 6 bits of data and 4 bits of >control information from the master controller. All of the fuel injection >systems would receive the same data, but it would be different (of course) >than the data system for the ignition module. These modules would be >fed data directly from the various inputs that they need to calculate >the correct amount of fuel. > >The master controller would cordinate everything for the other modules. It >would receive data from the cam position sensor (it needs to know how fast >the engine is running and if it is running at all), the knock sensor, >temperature, oil pressure, and others. It would not be directly controlling >either the ignition or the fuel injection. Those modules run on there own. >It would be able to tell the ignition system to advance or retard the timing >a number of degrees through the data and control information. It would also >tell the ignition system if it should run or not. It interfaces with the >fuel injection modules in much the same way. It tells then when to run, and >it can tell it to richen or lean the mixture by a certain percentage. If >the master controller tells it to lean out the mixture outside of the >boundaries for the mixture, the fuel injection controlers can set an error >flag and keep running rich. Blubbering rich being preferable to "piston >melting" lean any day. > >This system would not use any type of data bus. Do to the small about of data >going to the sub modules (and data does not go to the master controller from >the sub modules), there is no need for a data bus. Also, each controller >runs its own program and deals with learning on its own. One problem with >this idea is that to change all of the programs (say to redefine the data), >you would have to pull all 4 eeproms. Truthfully, this I can live with. >Another advantage is that you could build and test the ignition system before >you had to make the rest of the system. This would at least let you know >that your timing information from the cam and crank senors was as you >predicted. Also, there is no shortages of input capture and output compare >ports. > >One question I do have how should I buffer the various signals that need to >go to multiple modules? Would I have to? Would the standard input filtering >be enough of a buffer to feed up to 4 inputs simultainiously? I would love >to here everyones ideas and opinions on this idea. I do beleive I will be >looking into it somemore. And if this idea was brought up in the past and >well and throughly shot down, I appologize for bringing it up again. >Thanks for you input. > >Clint >ccorbin@xxx.com > tie all 4 micros to a 4 port memory and youll have a common data and program pool ; this has been done before especialy in the old days when ups ran at 1 megahertz. question : who uses intel ups in automotive or engine control applications. ------------------------------ End of DIY_EFI Digest V1 #37 **************************** 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".