DIY_EFI Digest Thursday, March 2 2000 Volume 05 : Number 080 In this issue: Injector boss flush with intake runner? Re: DIY_EFI Digest V5 #79 saab ignition Re: cheap data aq system Re: Multi-processor EFI See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Wed, 1 Mar 2000 08:36:39 -0800 (PST) From: Clay B Subject: Injector boss flush with intake runner? After lots of drilling and grinding, it looks like the Rochester '989 injectors end up about .100" above the inside of the intake runner wall. Is it appropriate to cut the boss flush with the inside of the intake port. Or, is there any benefit to providing a small upstream protrusion to allow the fuel stream to propagate further, before airflow blows it towards the intake valve. Injectors are vertical on a V8, for a 45 degree orientation relative to the port. - - Clay - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Wed, 1 Mar 2000 08:53:18 -0800 From: "John Dammeyer" Subject: Re: DIY_EFI Digest V5 #79 Hi Jack, I just completed and engine controller for 4Cyl Honda Engines. A custom controller was desired because: a) The reduction drive for propellors was in the way of the stock distributor; b) the customer wanted dual ignition for aircraft redundancy; c) the customer needed fuel injection and wanted to use as many Honda parts as possible. A prior version involved a carburator and just dual ignition and used a couple of Hall sensors with two PIC micros on one circuit board. The first Injection version has everything except dual ignition so addresses the controller side of things you mention. Fascinating question though. If absolute position information is available for each cylinder then designing a single PIC or ATMEL processor on a per cylinder basis would be an interesting project and certainly scalable up to V12 engines. It gets more complicated if you wish to use the newer 'waste spark' coils because now you need to work with two cylinders at a time and handle overlapped injector timing. i.e. With a one cylinder engine and a 720 degree cycle you have a total of 4 events to manage; Injector on/off and coil current on/off. A two cyl. engine doubles this along with overlapping injector times depending on engine load and the complexity at that point isn't any more difficult than 4 or 6 or 8 or 12 assuming the processor is fast enough relative to engine speeds. Now let's talk cost. The four cyl. controller I designed drives two coils through a Capacitive Discharge technique and also drives 4 injectors using two VND05 devices. So this could be scaled back to a two cylinder project at the cost of doubling up the Coil and Capacitor storage section which is shared. But... The cost of the processor, EPROM and RAM are insignificant compared to the cost of the interface circuitry, circuit board, the box, the connectors and the CAN network used for debugging. Just throwing two MAP sensors into the engine for two controllers raises the price far to much compared to what you would gain. Even with single quantity pricing, a single C167 or Motorola 16/32 bit processor on one circuit board is still less expensive than bank of 8 individual processor boards. Good idea but not economically viable - especially for a hobby. Cheers, John >------------------------------ > >Date: Tue, 29 Feb 2000 10:43:19 -0500 >From: "Jack E. James" >Subject: Atmel & List Stirring > >Hi Bernd, > [snip] >controllers becomes available, it would seem that there might be an >advantage to >separating cylinders, like two identical 4 cylinder controller's for >a V8. Two ignition sensors (like Pertronix modules switching resistor >loads to provide position logic) and parallel mass air flow or 2- MAF >units for less air flow loss. Or one controller for part throttle >and another for full throttle. Just curious about multiple processors, >having thought about using some of the faster PIC,s for each >cylinder. [snip] >Jack > - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Wed, 1 Mar 2000 16:39:57 -0500 From: "Camden Lindsay" Subject: saab ignition This is a multi-part message in MIME format. - ------=_NextPart_000_000E_01BF839C.C79F35A0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hello, I'm just getting started on a project; an 84 audi with a newer turbo = motor. I am interested in doing my own work/ using a computer/etc. I = was wondering if you had any of the saab systems left, and if not can = you get them? Also, I would be interested in how to interface the saab = ignition setup with any other or a custom setup. =20 Thank You, Sincerely, Camden Lindsay - ------=_NextPart_000_000E_01BF839C.C79F35A0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hello,
I'm just getting started on a project; an 84 audi = with a newer=20 turbo motor.  I am interested in doing my own work/ using a=20 computer/etc.  I was wondering if you had any of the saab systems = left, and=20 if not can you get them?  Also, I would be interested in how to = interface=20 the saab ignition setup with any other or a custom setup.  =
Thank You,
Sincerely,
Camden Lindsay
- ------=_NextPart_000_000E_01BF839C.C79F35A0-- - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Wed, 1 Mar 2000 18:13:41 -0500 From: "Braman Wing" Subject: Re: cheap data aq system Thanks for all the responses - I had no idea there would be so much interest. As I said, I am an ME by profession, and I don't have a lot of electronics knowledge, so any suggestions are appreciated. if someone else wants to take the lead on this, by all means please do so. I can already see a number of ways to improve on this design. I am already planning to use an external regulated power supply. Another likely problem seems to be the protection of the inputs - in the schematic I found there are 100k resistors which are said to protect against 14V transients, but I'd eventually like to have better protection than this. Someone mentioned that the145050 doesn't like higher voltage analog inputs - For now I am simply going to keep the inputs at 0-5V, but if there is a way to get around this, I'd like to incorporate it in the final version. I am going to go ahead and breadboard it and see if I can get it to work at all in the next week or 2. I'll report my results as I go along. Braman - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 2 Mar 100 09:45:00 +0800 (WST) From: Bernd Felsche Subject: Re: Multi-processor EFI John Dammeyer writes: >>------------------------------ >>From: "Jack E. James" >>Hi Bernd, >[snip] >>controllers becomes available, it would seem that there might be >>an advantage to separating cylinders, like two identical 4 >>cylinder controller's for a V8. Two ignition sensors (like >>Pertronix modules switching resistor loads to provide position >>logic) and parallel mass air flow or 2- MAF units for less air That's actually done in many multi-bank engines. Only recently has there been sufficient "processing power" been available to run a V8 as well on a single CPU - according to the big makers anyway. ;-) >>flow loss. Or one controller for part throttle and another for >>full throttle. Just curious about multiple processors, having >>thought about using some of the faster PIC,s for each cylinder. Running each cylinder on its own is probably not that good an idea IMHO as it's the whole engine you need to control. The necessary interchange of information is probably going to be the limiting factor. >>Jack [interesting bits snipped] >Fascinating question though. If absolute position information is >available for each cylinder then designing a single PIC or ATMEL >processor on a per cylinder basis would be an interesting project >and certainly scalable up to V12 engines. It gets more complicated >if you wish to use the newer 'waste spark' coils because now you >need to work with two cylinders at a time and handle overlapped >injector timing. Depends how you group the cylinders - space them at 360 degrees apart and allow for an injector off-on during each rev. That doubles the minimum close time of the injector which reduces the maximum delivery by a small margin and decreases injection accuracy by a small amount. The VW Digifant starts an injector cycle for each TDC and BDC. (Much like L-Jetronic.) That's every 180 degrees of crank because it runs 4 cylinders and 4 injectors at once. There's no absolute position available. Nor is it useful because all injectors wired in parallel and separate wiring would require another output (which is "available") and a separate harness/connector-pin to group the injectors. >i.e. With a one cylinder engine and a 720 degree cycle you have a >total of 4 events to manage; Injector on/off and coil current >on/off. A two cyl. engine doubles this along with overlapping >injector times depending on engine load and the complexity at that >point isn't any more difficult than 4 or 6 or 8 or 12 assuming the >processor is fast enough relative to engine speeds. You could use a common interrupt (clock) for crank position. Each PIC can be told to watch for a particular clock tick for each event. There is the constraint of feeding counter information quickly to the PICs in time. It's conceivable though, that a "broadcast" to all the PICs could be used to give base information and to have each perform some simple arithmetic to determine appropriate trigger values. Think of it as having a scalable number of counters with multiple output-compare registers (OCRs). With a small number of cylinders and "common" events, that's not necessary, especially if you can reset the OCRs quickly enough. >Now let's talk cost. The four cyl. controller I designed drives >two coils through a Capacitive Discharge technique and also drives >4 injectors using two VND05 devices. So this could be scaled back >to a two cylinder project at the cost of doubling up the Coil and >Capacitor storage section which is shared. >But... The cost of the processor, EPROM and RAM are insignificant >compared to the cost of the interface circuitry, circuit board, the >box, the connectors and the CAN network used for debugging. Read about internal packaging option below. >Just throwing two MAP sensors into the engine for two controllers >raises the price far to much compared to what you would gain. Even >with single quantity pricing, a single C167 or Motorola 16/32 bit >processor on one circuit board is still less expensive than bank of >8 individual processor boards. If you look at the possibilities presented by high-speed inter-processor busses and cheap packaging options such as SIMM, then a scalable option, at least for the data-acquisition and driver sections becomes attractive. The high-level control strategy is probably better achieved by a "proper" CPU with sufficient address and physical memory space as well as crunch capability, driving the slave processors. I initially brought up the possibility of using multi-processors as a means of expanding capabilities of the specialised chips which, for example, cannot address external memory directly. Atmel 8535 and 8515 (or 4414) working in tandem provide not only a large number of analogue inputs, as well as digital I/O, but also direct addressability of (64kbytes of) external SRAM. There's also the bonus that they can flash each other in-situ, data provided externally via a serial port. >Good idea but not economically viable - especially for a hobby. Like you, I doubt that one-PIC-per-cylinder is economically viable; though it is intellectually stimulating. The question of scalability remains: If you run out of capacity, do you perform a leap in architecture, or do you use tandem processors for the required functions? For the "hobby" situation, the 8-bit (or even PIC) solution is attractive to get started. Running several in tandem may be a good way for you to grow a system whilst building on proven subsystems. Eventually, I guess, you'll "hit the wall" and have to leap to a more complex base architecture. The trick may be to gaze into the crystal ball and see where that wall is located - and see if it matters. - -- Real Name: Bernd Felsche Email: nospam.bernie@xxx.au http://www.perth.dialix.com.au/~bernie - Private HP - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ End of DIY_EFI Digest V5 #80 **************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. 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