DIY_EFI Digest Friday, 6 December 1996 Volume 01 : Number 372 In this issue: EFI for 225 slant 6 needed , Info about upgrades to mopar/chrysler oem EFI sytems Re: Injector Connectors Re: DIYEFI FAQ Re: ALDL to Serial connector: Read this Re: crankshaft/flywheel encoder patterns Re: crankshaft/flywheel encoder patterns re: Flywheel/Encoder patterns Re: Flywheel/Encoder patterns Whoops Re: injector duty cycles Re: Injector Connectors re: Flywheel/Encoder patterns See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Mike.Olsson@xxx.com (Mike Olsson) Date: Thu, 5 Dec 1996 11:59:18 +0100 Subject: EFI for 225 slant 6 I'm new at this mailing list, so I figure I should try it out and see where it gets me. I have a nice 225 slant 6 ( \6 ) currently sporting a 2-port 32/36 DGAV Weber which I bought from Clifford performance a couple of years ago. It works OK which means that I've gotten a little bit more power and torque without sacrificing mileage. I still feel though, that mileage could be better. EFI has obviously made wonders with some American built engines that are as old or older than the \6; so why not? I contacted Mopar Performance a couple of years ago and they have considered upgrading the \6 and made some testings with various systems of which they named Haltech (and one more that I don't recall). Haltech offered a system, but due to the expense I really would like to have some feedback before I go ahead and buy something. Also it could be difficult to find spare parts in a hurry here in Sweden. Now I have this idea of modifying an excisting system that can be found over here used or new. Maybe the Jeep inline 4.0 system would work? Does anyone of you guys out there know of a successful installation of EFI in a \6?? Please give me tips and advice on how to proceed, because I really want to do this, Thanks, Mike Olsson ------------------------------ From: "james r. mincey" Date: Thu, 05 Dec 1996 18:51:16 -0800 Subject: needed , Info about upgrades to mopar/chrysler oem EFI sytems I am considering an engine upgrade in my 1995 dodge ram pickup. currently the truck has a 230hp 360ci engine and I would like to purchase a 380hp 360ci from mopar performance. The new engine was tested for hp using a 750cfm holley carb. I would like to upgrade my existing EFI system to match the operating paremeters and benifits of the holley carb. I plan to replace the oem engine computer with the the high performance version offered by mopar performance. Now some question.. 1.) Is the two barrell oem throttle plate large enough to flow 750cfm or will i have to replace it with a four barrell version ?. If replacement is needed where can I get this part? Will this part work with the engine computer and wiring harnass. 2.) are the Oem fuel injectors adequate or should they be replaced and with what ?. 3.) would increasing the fuel pressure help instead of replacing the injectors. 4.) Information on any recomended reference manuals that help shed some light on this matter. note (planning to use stock ignition and connections.) The techs at mopar performance seem to be reluctant to give out much information so I would be extremely grateful for any received from any one reading this. It would probably be easiest if I could recieve any replies at my mail box (jrm261@xxx. thanks in advance jr mincey ------------------------------ From: Neville Newman Date: Thu, 5 Dec 1996 09:23:48 -0800 (PST) Subject: Re: Injector Connectors i don't want to insult anyone's intelligence, but is it possible that this wide range of connectors came from a selection of GM/Suzuki, GM/Toyota, GM/Daewoo, and GM/proto-American cars? -neville > > Curt in my scrounging I now have 4 different type of injector connectors > > and all of my parts have come from GM vehicles. If the injectors are of > the > > same brand then you'll be pretty close. So far all of the ones using the > > lucas injectors have been the same. > > > > John Faubion > > Don't know what to tell ya John. Everyone I've ever ran across has been > equiped with Delco injectors. The square 2-prong connector with a wire > clip retainer. ------------------------------ From: Stephen Dubovsky Date: Thu, 5 Dec 1996 15:06:46 -0500 Subject: Re: DIYEFI FAQ >(what is a Hall effect sensor?!). Ok, imagine a piece of square (or rectangular) silicon semiconductor placed flat on a table. If it is doped uniformly either n-type or p-type, and a voltage is applied across the wafer on the left and right (connections L & R), the voltage on the edges nearest and farthest away from you will be 0v (connections N & F) (if the connections are made w/ the same x-coordinate so they dont detect the applied voltage gradient). Now if a magnetic field is applied normal to the table (through the chip) there is a neat phenomenon called the hall effect that says there will be some measureable voltage at terminals N&F that is somewhat proportional to the applied voltage at L&R, the geometry of the wafer, the doping concentration, and the magnetic field strength. Since the first three are usually fixed, the output of a hall sensor is proportional to an applied magnetic field. This means you can glue a magnets to a flywheel and detect when they go by. It also allows you to build things like non-contact DC current meters because you can measure the magnetic field around a wire when a current passes through it (remember the right hand rule from physics?). In real life they tend to be a little non-linear, but there are meany creative ways to get around this. If your looking to do something like detect magnets, then this doesn't matter anyway. Hope all this helps. If you need more info plz feel free to ask. The best analogy I can think of why this happens (w/o going into fields theory) is to remember that a magnetic field is used to deflect the trajectory of electrons in a TV tube, something very similar is 'bending' the e paths towards one side of the wafer. SMD - -- Stephen Dubovsky dubovsky@xxx.edu 95 Yamaha FZR600 83 Porsche 911SC 84 Jeep Cherokee ------------------------------ From: Daniel Burk Date: Thu, 05 Dec 1996 19:36:49 -0800 Subject: Re: ALDL to Serial connector: Read this I must put out a warning: Many of the ECM's from the early 80's do NOT output TTL levels, but a SES lamp voltage: aka 12 Volts! My Trans Am does. The 8192 data rate seems to have been implemented on a very few 1985 models, and on most of the 1986 models. Most of the 160 baud systems have a 20 to 25 byte data stream, while the 8192 streams will contain as many as 47 bytes. The modes are actuated by the resistance that you place across the pins A & B. If you use a 10K ohm resistor, you get one of the modes. a 3.9K resistor triggers another mode, and 500 ohms or less triggers the "paperclip" mode that blinks the SES lamp. Some ECMs support both the 160 baud and the 8192 baud data stream. ------------------------------ From: Mark Eidson Date: Thu, 5 Dec 1996 17:05:13 -0700 Subject: Re: crankshaft/flywheel encoder patterns At 10:56 AM 12/3/96 -0800, you wrote: >Mark Eidson wrote: >> >> This is the same approach I have come up with but I'm only in the thought >> process. Are you going to sequence your counters so that each cylinder will >> have a programmable injection timing? This will also work for ignition. I >> thought a phase locked loop running at a higher frequency would give more >> accuracy than 1 degree of cam rotation but can't figure out an easy to get >> the dynamic range required. me >> *************************************************************************** >> * Mark Eidson Voice: (602)752-6513 * >> * Staff Design Engineer Fax: (602)752-6000 > >Hi Mark, > >Yes, I plan to sequence them, and I'm using the same approach for >ignition coils. Also, with one edge per crank degree, we can narrow our >resolution to 0.5 degrees of cam rotation not 1 degree, and for my >purposes this is accurate. I know there are systems out there that claim >they are more accurate, but I don't know beyound 1/2 degree if it makes a >difference. > >The reason I decided to go this route was to relieve the processor from >too many interrupts. I plan to set the processor up to be interrupted on >every rising edge of the crank sensor (once every 2 degrees of crank >rot). When there is a rising edge on the CAM, I'll set angle to zero, >and increment by two on every crank interrupt. I then reload the >counters (by writing to a memory location), when their proper angle comes >up. > >I'd like to discuss this more, but I'm out of time right now. Write me >back on what you think. > > Have you thought of using the flywheel or flex plate teeth for the source of timing pulses? This would give more resoultion if accurate pickup can be made. I was thinking of using a single counter and decoders for each injector and spark plug. The cam pulse resets the counter and each set of decoders would be loaded with the start and stop count. This may take more hardware but allows for positioning and duration control. Once loaded the system requires no CPU action under steady state conditions. me *************************************************************************** * Mark Eidson Voice: (602)752-6513 * * Staff Design Engineer Fax: (602)752-6000 * * Manager System Integration and * * Verification E-Mail: mark.eidson@xxx.com * * VLSI Technology, Inc. * * 8375 South River Parkway * * M/S 265 * * Tempe, Arizona 85284 * *************************************************************************** ------------------------------ From: Mazda Ebrahimi Date: Thu, 05 Dec 1996 19:34:39 -0500 Subject: Re: crankshaft/flywheel encoder patterns > Have you thought of using the flywheel or flex plate teeth for the source of > timing pulses? This would give more resoultion if accurate pickup can be > made. I was thinking of using a single counter and decoders for each > injector and spark plug. The cam pulse resets the counter and each set of > decoders would be loaded with the start and stop count. This may take more > hardware but allows for positioning and duration control. Once loaded the > system requires no CPU action under steady state conditions. me That's exactly what I'm going to do. I basically use the crank sensor input for three purposes: 1-To increment my degree count, 2-To trigger my counters for injectors and coils, and 3- to calculate RPM based on period of the pulse. I use the cam sensor to reset the degree count to zero. I'm using separate counters for each device right now. I didn't design the board myself, but I'm pretty sure there is a decoder that I write to, which inturn loads the proper counter. The counters then count down based on the crank pulse. Best Regards, Mazda Currently, I'm using a 180 tooth wheel fixed to the harmonic balancer. ------------------------------ From: RABBITT_Andrew@xxx.au Date: Fri, 6 Dec 1996 09:30:12 est Subject: re: Flywheel/Encoder patterns >Currently, I'm using a 180 tooth wheel fixed to the harmonic >balancer. a word of warning here, these things are designed to wobble about, therefore if your encoder is rigidly fixed to the crankshaft you'll be OK, but if it's just attached to the damper mass, your timings will be screwed up depending on the phase relationship between the damper mass and the crankshaft. Andrew Rabbitt ------------------------------ From: Mazda Ebrahimi Date: Thu, 05 Dec 1996 21:24:58 -0500 Subject: Re: Flywheel/Encoder patterns RABBITT_Andrew@xxx.au wrote: > > >Currently, I'm using a 180 tooth wheel fixed to the harmonic > >balancer. > > a word of warning here, these things are designed to wobble about, > therefore if your encoder is rigidly fixed to the crankshaft you'll be > OK, but if it's just attached to the damper mass, your timings will be > screwed up depending on the phase relationship between the damper mass > and the crankshaft. > > Andrew Rabbitt Thanks Andrew. I'll look into it as soon as I get to work tomorrow. By the way, can you explain your thinking on the 60 tooth wheel. I know Electromotive uses both the 60 tooth design and the 120 tooth design. Best Regards, Mazda ------------------------------ From: Todd King Date: Thu, 05 Dec 96 19:44:00 PST Subject: Whoops <<< Thanx for the recap on the last month's DIY_EFI list. I didn't need the hard drive space, anyway :] regards dn dnorquay@xxx.com >>> Sorry guys- I was offsite at a travelers workstation and must have severely SNAFU'd my reply process to the DIY_EFI list. Please accept my apologies for bouncing the whole list back in the reply. Todd Todd_King@xxx.com ------------------------------ From: Todd King Date: Thu, 05 Dec 96 20:21:00 PST Subject: Re: injector duty cycles <<< From: Mazda Ebrahimi Date: Wed, 04 Dec 1996 20:22:56 -0500 Subject: Re: injector duty cycles ... > I find that at WOT my injectors go greater than 99% duty cycle for most of the > Todd Todd_King@xxx.com Thanks for the info. Is this a stock engine? Are the injectors peak and hold type? >>> <<< From: "William A. Sarkozy" Date: Wed, 04 Dec 1996 21:44:47 -0800 Subject: Re: injector duty cycles ... I gather that at 2000 RPM with WOT you're pumping in the same amount of fuel as you are at 6000 RPM with WOT???? 100% duty cycle with (essentially) the same fuel rail pressure. Seems like we're going to run a little fat down low, boys. Help me out, here. >>> The engine was nearly stock. I am installing ported heads presently so will report on it when it gets back on the road. These results are part of my previous comments about not getting caried away with what's necessary to have a useful EFI setup. The car was low 12's at about 110mph as it was; yes, the O2 voltage drops during a run under these conditions so to end up safe at the end of a run you must start fat at the beginning. I don't think most people really consider the overall injector dynamic range problem very deeply (until they are actually facing it). Consider that this engine is small (3.8L, 231"); the fuel required at idle is small. The engine is also turbocharged/ intercooled; the fuel required at WOT is BIG :-) , while the time to deliver it shrinks with every increase in RPM. The injectors were 34 #/hr, high impedance (sat type?); I have a set of 50 lb'ers waiting for the install time. The inj sizing compromise must be made somewhere, unless one wants to run staged injectors (ie multiple injectors per cylinder)... Glad the info has stirred some thoughts out there. Todd Todd_King@xxx.com ------------------------------ From: "John Faubion" Date: Thu, 5 Dec 1996 22:39:50 -0600 Subject: Re: Injector Connectors > i don't want to insult anyone's intelligence, but is it possible that > this wide range of connectors came from a selection of GM/Suzuki, > GM/Toyota, GM/Daewoo, and GM/proto-American cars? Well call me what you will but I don't consider ANY import under the GM flag as a GM product. As for the source of the connectors 2 types were from Cadilacs, one type was from a Bereta, and the rest are from several makes all using Lucas injectors. John Faubion jfaubion@xxx.net ------------------------------ From: RABBITT_Andrew@xxx.au Date: Fri, 6 Dec 1996 12:32:54 est Subject: re: Flywheel/Encoder patterns >can you explain your thinking on the 60 tooth wheel. I know >Electromotive uses both the 60 tooth design and the 120 tooth design. We're looking at a 60 tooth wheel (over a 36 tooth) to improve our timing accuracy when we use missing tooth reference markers. We use the industry standard practice of measuring time interval between edges and using this time to extrapolate the position over the next interval. Usually clocks with a 250ns to 1us time resolution are used to drive the counters. There are a couple of other issues driving this too, which are specific to our design and not applicable to MPI systems. Andrew Rabbitt ------------------------------ End of DIY_EFI Digest V1 #372 ***************************** 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".