DIY_EFI Digest Friday, 21 June 1996 Volume 01 : Number 173 In this issue: Re: Bosch Motronic Questions Re: DIY_EFI Digest V1 #172 Turbo and Efi relations.... Re: Turbo and Efi relations.... Re: Anybody build their own 5th wheel? Re: Bosch Motronic Questions Re: Home-grown 5th wheel project--wheel lacings Re: Bosch Motronic Questions Re: oxygen sensor Re: fuel pickups & filters? Fuel Injection Software Re: oxygen sensor Re: Bosch Motronic Questions See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: "Gregory Chan" Date: Thu, 20 Jun 1996 08:19:44 EDT Subject: Re: Bosch Motronic Questions > > 1) I've been told that it is possible to lessen the spring force on the door > of the Air Meter by moving the spring back a few notches, which may > somewhat lessen the throttle lag issue. I've tried to get to the spring by > removing the bottom plate of the meter, but apparently access to the > spring is from the top. My question.... How do you get the black plastic > top off without destroying it in the process? I'd also be interested in > hearing from anybody who has experience with this modification. > It is a necessity to play with the AFM with cams of large duration. My experience was that my motor would not idle at all until I adjusted the AFM. To get at the spring take a hobby knife and cut around the black plastic. You will see some type of glue around the edge between the metal and the plastic and this is what you should cut. You can then pry the cover off and adjust the spring . One direction is rich and the other leaner. Good luck. gchan@xxx.ca ------------------------------ From: talltom Date: Thu, 20 Jun 1996 08:36:36 -0700 (PDT) Subject: Re: DIY_EFI Digest V1 #172 >------------------------------ the way to get the plastic cover off is with a couple of butter knives. Pry slowly and gently completely around the edges a couple of times at which point it will have loosened in places, and continue until it comes off. You will probably break some small portions by the mating edges but this will be minimal. I have been able to reglue all so far with garage man schmuck. Record the position of everything both before and after you make any moves. Every time I've done this, I ended up back at the same point I started. DON'T SAY WHO TOLD YOU! > >From: Brad Anesi >Date: Wed, 19 Jun 1996 18:06:52 -0600 >Subject: Re: Bosch Motronic Questions -Reply > >Hi Werner- > >>If you loosen the spring about two notches (about 2% point AFR) it >>should help the hesitation if there is any. But if you use a O2 sensor >>normal running will not change. > >Thanks for the reply - so far, you're the only one who has been bold >enough *not* to suggest I should committed to an institution for trying to >touch anything inside that box! I am using an O2 sensor, so I also believe >normal running will be unaffected. My sole objective is to get the "barn >door" to open more quickly, enabling the air/fuel mixture to enter the >combustion chamber a split-second quicker. > >BTW, what do you mean by 2% point AFR? > >Thanks again, > >Brad > >------------------------------ > >------------------------------ Why do you guys insist on reinventing the wheel? Ever heard of a motorcycle? Kawasaki zx11 speedo goes to 175 I believe, is that enough? I'd think that one could tie into the digital motorcycle speedos for reference to a cpu. They drive off the front wheel, in fact I've even seen cars that the speedo cable went the spindle and was driven by a hole it fit into in the dust cover. ` If 175 mph isn't enough I'd start looking for airplane parts. > >From: Darrell Norquay >Date: Wed, 19 Jun 96 19:06 PDT >Subject: Re: Anybody build their own 5th wheel? > >At 02:07 PM 6/17/96 -0400, you wrote: >> >> The second two are going to come from a 5th wheel that I want >>to make from 10 speed bicycle tire. Has anyone had any experience with >>making one of these? >> >> Does anyone have any suggestions or comments on how I can improve >>this design? Any suggestions for an LED/Photo-receptor package that is not >>influenced by stray light? > >I think you would be much better off going to a "photo interrupter" type >system than a reflective sensor. These are sometimes called "slotted >optoswitches" and come in several different flavors. As long as you use >infrared emitter/detector pairs, ambient light should not affect it too >much, other than possibly direct sunlight. A small "hood" should take care >of this. The interrupter style sensor could even be used with the original >equipment sprocket and hub, a much more practical arrangement for what you >have in mind than either magnetic reed switches or reflective optos. > >As some people have stated, detecting a spoke at 120+ MPH would be a real >challenge, and I don't think a magnetic reed switch will activate that fast >either, although a hall effect sensor might work. The bicycle speedo >approach may also work, but they are not really rated for those speeds, and >you may end up missing pulses. When was the last time you saw a bicycle >doing 120 MPH? :] > >regards >dn > >------------------------------ > ------------------------------ From: "David W. Taylor" Date: Thu, 20 Jun 1996 10:08:19 -0700 Subject: Turbo and Efi relations.... A while back I posted a few questions about MAP sensors and forced induction. Welll after some more research I'm back with another question... One of the companies I contacted in comparing roots and turbo superchargers sugested a system he said they use,,, They add a circuit that clamps the map output at 1 inch of mercury whenever the boost is in positive pressure, they then increase the fuel pressure proportionately to boost with some basic analog circuit. How does this sound?? It seems too simple but the company does seem to produce some good stuff..... - -- David Taylor dwtaylor@xxx. My opinions are mine ,, and nobody elses. ------------------------------ From: Frank Parker Date: Thu, 20 Jun 1996 14:44:47 -0600 (EDT) Subject: Re: Turbo and Efi relations.... > Subject: Turbo and Efi relations.... > > > One of the companies I contacted in comparing roots and turbo > superchargers sugested a system he said they use,,, > > They add a circuit that clamps the map output at 1 inch of mercury > whenever the boost is in positive pressure, they then increase > the fuel pressure proportionately to boost with some basic > analog circuit. > > How does this sound?? > > It seems too simple but the company does seem to produce some > good stuff..... That is what Carroll Supercharging does. Good but $$$. frank ------------------------------ From: SnoMo1@xxx.com Date: Thu, 20 Jun 1996 15:58:47 -0400 Subject: Re: Anybody build their own 5th wheel? Has anyone thought of picking up a DigiKey catalog? There seems to be a good selection of OMRON "slot" type optical sensors available. These units will handle frequencies to 1000hz, have built-in amplifiers, and are relatively inexpensive ($15.00 USD). They should be very immune to external light sources. It seems these "slot" type devices would work well with some type of disc attacted to the wheel hub. Just my $.02 worth. By the way, if your need a DigiKey catalog, call 1-800-344-4539. Mark SnoMo1@xxx.com ------------------------------ From: WERNER_HAUSSMANN@xxx.com Date: Thu, 20 Jun 1996 18:21:46 -0400 Subject: Re: Bosch Motronic Questions To get the plastic cover removed from the Air Meter, take and X-acto knife and remove the selastic, silicone caulking type material as much as you can. Then run the knife between the plastic and metal as best as you can. No need to cut the plastic. Now pull on one corner slowly to give time for the selastic to loosen and tear inside. You might try to get it started at the connector. Anyway if you pull slowly to loosen one area you can work around the rest of the meter. The cover is held on by the selastic and will come free by pulling it off. You'll see how the spring can be adjusted after you open it. Mark it before you move it!!!!! If you loosen the spring about two notches (about 2% point AFR) it should help the hesitation if there is any. But if you use a O2 sensor normal running will not change. Can't help on the EPROM. Werner ______________________________ Reply Separator ________________________________ _ Subject: Bosch Motronic Questions Author: Non-HP-owner-diy-efi (owner-diy_efi@xxx.edu) at HP-ColSprings,uugw2 Date: 6/19/96 11:46 AM Two questions for the collective... 1) I've been told that it is possible to lessen the spring force on the door of the Air Meter by moving the spring back a few notches, which may somewhat lessen the throttle lag issue. I've tried to get to the spring by removing the bottom plate of the meter, but apparently access to the spring is from the top. My question.... How do you get the black plastic top off without destroying it in the process? I'd also be interested in hearing from anybody who has experience with this modification. 2) What blank E/PROM chip do I need to order for the ECU? (I've got access to a chip programmer and wanted to make back-up copies of my current chips). Also, any suggestions on sources? Thanks, Brad (banesi@xxx.com) '86 Porsche 911 Coupe '91 Alfa Romeo 164 ------------------------------ From: WERNER_HAUSSMANN@xxx.com Date: Thu, 20 Jun 1996 18:21:12 -0400 Subject: Re: Home-grown 5th wheel project--wheel lacings Another approach is to buy one of the wheels used by EFI systems for sensing crank position. Elecromotive sells such wheels and the sensors for them. Werner ______________________________ Reply Separator ________________________________ _ Subject: Re: Home-grown 5th wheel project--wheel lacings Author: Non-HP-owner-diy-efi (owner-diy_efi@xxx.edu) at HP-ColSprings,mimegw2 Date: 6/19/96 12:18 PM As your sensor gets closer to the hub though the spoke spacings get less regular--that is, the spokes are not spaced exactly 10 degrees apart, half of the intervals will be more than 10 degrees and half will be less. If this won't cause any problems, great, but if it does you may have to lace up the wheels in a radial pattern. This requires shorter spokes and a bit of skill to get right. The 2X, 3X, and 4X patterns are used to transmit torque better and to bear more load. Those are not great concerns here so I'd give radials a go. Besides, a radial pattern just looks slightly more exotic. Better yet, why not use a rear wheel hub with threads for the freewheel already built in. Then you can fabricate a circular plate to mount your magnets that will screw onto to those threads--you can even use off the shelf locking rings to lock it in place. It would be much more secure than trying to get a reliable mount to a 14 gauge spoke. Unless of course you use aero bladed spokes. Or why use magnets at all if you have a stable plate. drill small holes in the plate at regular intervals and use an optical system. Any machine shop that cuts gears should be able to keep the intervals regular. Or, here's another approach: Use an aero disc (flat not lenticular) and mount anything anywhere. You might be able to get a used one for not much money, many cyclists are going to DuPont or Spinergy 3 and 4 spoke style wheels anyway so a nice flat disc could be found on the used market. Best regards, Thomas Sparks At 21:20 6/18/96 -0400, you wrote: >Thanks Bruce, Orin, Dan and Peter for the wonderful input. I'll zip over to the >bicycle shop and get an idea of what the mag pickup looks like. I might be able >to do just as you suggested and mount a small magnet onto every other spoke. >There seem to be approx. 36 spokes on a typical wheel so that would be 18 >positions >which is one every twenty degrees. Based on my initial calculations using >36 spokes >on a 26 inch O.D. tire/rim combo, I would get a 1000 Hz signal at approx. >129 MPH. >Thus, with only 18 spokes, I should get a 500 Hz signal. > >I did a quick check on how much time a .100" thick spoke would break my >light beam >if I was monitoring near the edge of the rim. (20.5" dia.) I found that the >spoke >would obstruct the beam for only 60 microseconds at 129 MPH!! I'd have to >widen that pulse width by either using a 1 shot timer, or by moving the >sensor closer to the >hub. > > The research continues. > > BTW, I like the idea of correlating the data via integration of >the accelerometer data. I'll probably load it all >into MATLAB and crunch it in just that fashion. > >Cheers! > --Dan. > > > > ------------------------------ From: WERNER_HAUSSMANN@xxx.com Date: Thu, 20 Jun 1996 18:22:29 -0400 Subject: Re: Bosch Motronic Questions The Bosch Air Meter is a vane that is hooked to a logorithmic potentiometer. The output is usually in the form of two voltages. One voltage is fixed, the other is from the potentiometer. The ratio of the two voltages gives air flow. The vane changes the air stream cross section area to get air flow. There is also a thermistor to measure temperature. Changing the spring force will change the output voltage by approximately a multiplier for the range of the meter. Changing the screw adjustment of the meter will offset the output by a fixed air volume amount (much affect at idle, little at WOT) You can also change the calibration of the meter by changing the value of the fixed resistor. Some meters (non-bosh) do not have the fixed resistor. Using temperature, air flow x time for volume, and athmospheric pressure (may or may not be measured), the air mass is calculated with an analog computer (L-Jetronic), or digital computer (Motronic). If the air meter is used as an air flow device you cannot use the resistance of the potentiometer, you must use the voltage to get any accuracy. Werner ______________________________ Reply Separator ________________________________ _ Subject: Re: Bosch Motronic Questions Author: Non-HP-owner-diy-efi (owner-diy_efi@xxx.edu) at HP-ColSprings,shargw2 Date: 6/19/96 12:45 PM > 1) I've been told that it is possible to lessen the spring force on the door > of the Air Meter by moving the spring back a few notches, which may > somewhat lessen the throttle lag issue. I've tried to get to the spring by > removing the bottom plate of the meter, but apparently access to the > spring is from the top. My question.... How do you get the black plastic > top off without destroying it in the process? I'd also be interested in > hearing from anybody who has experience with this modification. I thought vane meters worked by correlating the momentum of a stream of air against the rotational position of the vane. Doesn't changing the spring force alter that relationship? Sorry, I can't help on the disassembly question. Anthony Tsakiris - --------------------------------------------------------------------------- The opinions expressed are my own and not necessarily those of my employer. ------------------------------ From: "Zublin, Bryan (SD-MS)" Date: Thu, 20 Jun 1996 16:52:00 -0700 (PDT) Subject: Re: oxygen sensor Thanks Frank, just the sort of information I was after but what do you mean by excursions. I have a fast response LED meter but i'm not sure what you are refering to here. ~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~ Justen Simpson simpson@xxx.au CRC for Freshwater Ecology, Uni of Canberra, Australia ~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~ > ---------- > From: owner-diy_efi-outgoing > To: diy_efi > Cc: diy_efi (postings) > Subject: Re: oxygen sensor > Date: Tuesday, June 18, 1996 10:30PM > > > ---------- > > From: toyota-mods-owner > > To: Craig A Terlau > > Cc: Daucott; mr2-digest; Toyota-mods > > Subject: oxygen sensor > > Date: Tuesday, June 18, 1996 3:35PM > > > > Here's one for the fuel injection experts. I'm presently running in my > > fuel injected turboed 18RG (without the turbo till the head gets > > retensioned) and i would like to run an O2 sensor, firstly to help tuning > > and secondly as a warning of lean outs at high boost. Apparently single > > wire sensors only last about a week when using leaded fuel as they get > > lead coated at low exhaust temps. Someone suggested that the 3 wire > > sensors (which are heated) may last longer. Has anyone tried this or know > > if it has been sucessfully used in a leaded fuel car. > > > > Cheers, > > > > ~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~ > > Justen Simpson simpson@xxx.au > > CRC for Freshwater Ecology, Uni of Canberra, Australia > > ~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~ > > > Yes, a heated sensor works very well. If you use both a digital vm > to read voltage and a fast responding led readout meter so you > can see excursions sensor makes, you can tell when sensor is getting > poisoned as range of excersions will reduce. Can regenerate sensor > for furthur use by running in unleaded car for few weeks. > Be aware that special sensors are used for a/f meters for reduced > flow and constant 650 deg C temperature. > > Frank Parker > > 93 Civic EX vtec custom turbo > 89 S-10 L98 V-8 with TFS/DFI/SuperRam > > > ------------------------------ From: MaxBoost@xxx.com Date: Thu, 20 Jun 1996 20:54:22 -0400 Subject: Re: fuel pickups & filters? All late model factory Nissan's use a nylon filter/sock on the bottom of their in tank pumps. They also use a filter before the fuel rail. The pickup filter is fairly course and keeps out the big stuff. Max. ------------------------------ From: pfenske@xxx.ca (peter paul fenske) Date: Thu, 20 Jun 1996 18:14:39 -0700 Subject: Fuel Injection Software >Hello Everybody: >Well John decided to be nice to me and finally posted some >fuel injection software I wrote for the HC11. This was >an early version but is enough to get everyone started. >To make this thing run you need an EVB and a few bits of >IO added. I built an io board which plugged into the EVB >and if anybody wants the layout ask me. Parts were >a MC3479 IAC driver, two LM1649 injector drivers, a quad driver >an op amp for the O2 sensor, a high side driver plus some >conditioning for the A-D. I can also provide a schematic. >Please beware of the following CAVAT. This thing will run >a motor albeit you may need some ether for starting in Nome. >However there were many sessions of bangs ect when things went wrong >BE CAREFULL!!!!!!!! >As for the code. At the time I didn't yet look too closely at other >people's code so it is purely my own. I think the documentation >could use some help so email me if you need any. >However it will give everyone an intro to fuel mapping, input >capture of ref timing, and loading the injectors. The IAC is >controled by a pot from one of the AD channels. The software >I developed for this function is quite flakey so if someone >wants help me with this. Unfortunately I used buffalo for >communication so I found operation above 3000 rpm difficult. >Take out the hooks to the monitor for high speed operation. >Good luck everyone. >Peter ------------------------------ From: Frank F Parker Date: Thu, 20 Jun 1996 23:00:01 -0400 (EDT) Subject: Re: oxygen sensor > > Thanks Frank, just the sort of information I was after but what do you > mean by excursions. I have a fast response LED meter but i'm not sure > what you are refering to here. > > ~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~ > Justen Simpson simpson@xxx.au > CRC for Freshwater Ecology, Uni of Canberra, Australia Just to the normal back and forth action of the sensor as it runs in closed loop. It will cycle back and forth from 0.0/0.1 to o.8-0.9 volts with an average voltage @xxx.7 a/f of about 450 mv. Both regular and digital meters will some the average but the the excersions down to 0 and up to 0.9 volts. Some digital meters with bar graphs or a led meter using the LM3914 bar graph chip will show the oscillations. frank parker ------------------------------ From: "Bosch, AN, Andrew, Dr" Date: Fri, 21 Jun 1996 10:14:41 UTC-2 Subject: Re: Bosch Motronic Questions > > 1) I've been told that it is possible to lessen the spring force on the door > of the Air Meter by moving the spring back a few notches, which may > somewhat lessen the throttle lag issue. I've tried to get to the spring by > removing the bottom plate of the meter, but apparently access to the > spring is from the top. My question.... How do you get the black plastic > top off without destroying it in the process? I'd also be interested in > hearing from anybody who has experience with this modification. > I used a razor blade to cut through the glue/sealant that holds the cover down; it was then quite easy to lever off. I eased the tension back by 3 notches; just be careful to hold everything in place when you undo the screw in there, otherwise the whole thing could probably unwind. I think it works great. There is no doubt that throttle response is crisper. Andrew Dr A. N. Bosch Physiology Department/ Sports Science Institute University of Cape Town Medical School P. O. Box 115 Newlands 7700 South Africa ------------------------------ End of DIY_EFI Digest V1 #173 ***************************** 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".