From owner-diy_efi Wed Oct 12 03:27:00 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA16583; Wed, 12 Oct 94 03:27:00 GMT Received: from eigen.ee.ualberta.ca by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA16578; Tue, 11 Oct 94 23:26:54 -0400 Message-Id: <9410120326.AA16578@coulomb.eng.ohio-state.edu> Received: by eigen.ee.ualberta.ca (1.37.109.4/15.6) id AA29034; Tue, 11 Oct 94 21:26:42 -0600 From: Dale Ulan Subject: Re: Injector timing qns. To: DIY_EFI Date: Tue, 11 Oct 94 21:26:41 MDT In-Reply-To: ; from "Jonathan R. Lusky" at Oct 10, 94 10:30 pm Mailer: Elm [revision: 70.85] Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI > It depends on the injectors, your fuel pressure, and how low you go. > On GM speed density systems this is compensated for by fudging the > volumetric efficiency tables.... sorta beat it to fit kinda thing. > Aftermarket speed density systems are similar, except that they generally > look up pulse width directly from (RPM,MAP) instead of pretending to > go through a VE step. Bottom line: compensation is done in the calibration, > the algorithms for speed density assume the injectors are linear. Actually, the GM system includes an injector *offset* which is a function of battery voltage (injector dead-time), which is added to the linear flow time. In addition, there is additional compensation for fuel pump voltage, which affects fuel system pressure, which is a multiplier factor used to scale the desired fuel flow. SAE Paper 810449, 'Mathematical Model of a Throttle Body Fuel Injection System' by Robert Esperti is a particularly good paper on this (although it gets mathematical). If you are into reading papers, 810494 and 810495 are pretty good, as well. Paper 790742, by G Czadzeck and R Reid of Ford, is a very good and readable paper on the Ford CFI 5.0L 1980 cars. It covers most of the 'twiddle factors' required to get the vehicle running properly. Also, paper 800164 on the GM TBI system is nice easy reading. Neither of these last two papers have any amount of hard math in them. The papers I mentioned are early ones because most later papers are virtually unreadable due to wall-to-wall mathematics. Even the 'Mathematical Model...' is semi-readable. The author discusses most of the characteristics of injectors. -Dale From owner-diy_efi Wed Oct 12 18:51:28 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA18863; Wed, 12 Oct 94 18:51:28 GMT Received: from wotan.compaq.com by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA18858; Wed, 12 Oct 94 14:51:26 -0400 Received: from twisto.eng.hou.compaq.com by wotan.compaq.com with smtp (Smail3.1.28.1 #12) id m0qv8bN-000vOaC; Wed, 12 Oct 94 13:40 CDT Received: from bangate.compaq.com by twisto.eng.hou.compaq.com with smtp (Smail3.1.28.1 #10) id m0qv89K-000uLNC; Wed, 12 Oct 94 13:11 CDT Message-Id: Received: by bangate.compaq.com with VINES ; Wed, 12 Oct 94 13:11:38 CDT Date: Wed, 12 Oct 94 11:44:47 CDT From: Steve=Ravet%Prj=Eng%PCPD=Hou@bangate.compaq.com Subject: Schematics for Johns SBC To: diy_efi Cc: Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI John Gwynne -- are the schematics for your board available? It'd be nice if we could get them posted somewhere that everyone could take a look at them, maybe have some discussions, then get something etched. Can you generate postscript files (or any other type of output) from them? If so, they could be placed on the WWW server. --steve From owner-diy_efi Wed Oct 12 21:17:23 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA20082; Wed, 12 Oct 94 21:17:23 GMT Received: from tomcat.al.noaa.gov by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA20077; Wed, 12 Oct 94 17:17:19 -0400 Received: from aztec.al.noaa.gov by tomcat.al.noaa.gov with SMTP id AA12903 (5.65c/IDA-1.4.4 for ); Wed, 12 Oct 1994 15:23:45 -0600 Message-Id: <199410122123.AA12903@tomcat.al.noaa.gov> Date: 12 Oct 1994 15:17:45 -0700 From: "Ciciora Steve" Subject: FW: Schematics for Johns SBC To: DIY_EFI Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI Someone writes: John Gwynne -- are the schematics for your board available? It'd be nice if we could get them posted somewhere that everyone could take a look at them, maybe have some discussions, then get something etched. Can you generate postscript files (or any other type of output) from them? If so, they could be placed on the WWW server. --steve ------------------------ Didn't John say that he would post a picture and schamatics on the WWW server? Try as I may, I can't seem to figure WWW out. If/when he does, could someone email me the files? Thanks! Dispite John's objections, I'm going to try to layout a pcb and see how much interest there is in manufacturing one. -Steven Ciciora From owner-diy_efi Wed Oct 12 21:56:07 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA20220; Wed, 12 Oct 94 21:56:07 GMT Received: from localhost.eng.ohio-state.edu by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA20215; Wed, 12 Oct 94 17:56:05 -0400 Message-Id: <9410122156.AA20215@coulomb.eng.ohio-state.edu> To: DIY_EFI Cc: jsg Subject: Re: FW: Schematics for Johns SBC In-Reply-To: Your message of "12 Oct 94 15:17:45 PDT." <199410122123.AA12903@tomcat.al.noaa.gov> Date: Wed, 12 Oct 94 17:56:05 -0400 From: John S Gwynne Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI -------- In message <199410122123.AA12903@tomcat.al.noaa.gov> , you write: | Didn't John say that he would post a picture and schamatics on the WWW | server? Try as I may, I can't seem to figure WWW out. If/when he does, coul | d | someone email me the files? Thanks! Dispite John's objections, I'm going to | try to layout a pcb and see how much interest there is in manufacturing one. | -Steven Ciciora Sorry about the delay.... I have had other (but less interesting :) ) work to do... I'll try to find time tonight or tomorrow.... objections???... I have no objection, in-fact I encourage it. I would like a few of them if the price is right. I not optimistic that they will be inexpensive, but I'm not an expert at layout. I've talk to two people about 4-layer versions and it did not sound cheap :(. But these "guys" don't normally consider cost to be as important as I would. John S Gwynne Gwynne.1@osu.edu _______________________________________________________________________________ T h e O h i o - S t a t e U n i v e r s i t y ElectroScience Laboratory, 1320 Kinnear Road, Columbus, Ohio 43212, USA Telephone: (614) 292-7981 * Fax: (614) 292-7292 ------------------------------------------------------------------------------- From owner-diy_efi Wed Oct 12 22:12:23 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA20354; Wed, 12 Oct 94 22:12:23 GMT Received: from fsa.cpsc.ucalgary.ca by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA20349; Wed, 12 Oct 94 18:12:21 -0400 Received: from aa.cpsc.ucalgary.ca (aa.cpsc.ucalgary.ca [136.159.4.5]) by fsa.cpsc.ucalgary.ca (1.6) id ; Wed, 12 Oct 1994 16:12:36 -0600 From: fridman@cpsc.ucalgary.ca (Robert Fridman) Received: by aa.cpsc.ucalgary.ca (1.2; from fridman@localhost) id ; Wed, 12 Oct 1994 16:11:22 -0600 Date: Wed, 12 Oct 1994 16:11:22 -0600 Message-Id: <199410122211.QAA04430@aa.cpsc.ucalgary.ca> To: DIY_EFI Cc: DIY_EFI In-Reply-To: "Ciciora Steve"'s message of 12 Oct 1994 15:17:45 -0700 <199410122123.AA12903@tomcat.al.noaa.gov> Subject: Re: FW: Schematics for Johns SBC Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI > Didn't John say that he would post a picture and schamatics on the WWW > server? Try as I may, I can't seem to figure WWW out. > ... > -Steven Ciciora If you are on a machine connected to the internet, then all you need is a WWW viewer executable which will run on your machine. Then fire up the WWW viewer and specify http://www.cpsc.ucalgary.ca/~fridman/diy_efi as the path. If you don't have a WWW viewer, I might be able to get you one. What machine type are you on? RF. From owner-diy_efi Wed Oct 12 22:32:43 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA20429; Wed, 12 Oct 94 22:32:43 GMT Received: from mercury.uah.ualberta.ca by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA20424; Wed, 12 Oct 94 18:32:39 -0400 Received: from [129.128.109.42] by mercury.uah.ualberta.ca (5.4.2/200.1.1.4) id AA06906; Wed, 12 Oct 1994 16:30:39 -0600 Message-Id: <9410122230.AA06906@mercury.uah.ualberta.ca> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Wed, 12 Oct 1994 16:33:17 -0600 To: DIY_EFI From: agc@mercury.uah.ualberta.ca (Andrei Chichak) Subject: Other Schematics Wanted Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI A while back I was on the DIY workstation list and the whole thing degenerated into a processor war with some wanting the group to use an R4000 others wanting to use Sparcs and one guy with a 68020 schematic in his hand. No consensus was ever achieved and the whole thing died. This group could go the same way once the HC11 gang get into the act or the PPC403 gets released (I sure hope not though). There are a bunch of things that all of these processors have in common that we should be talking about rather than starting processor wars. The interface hardware should be very similar and algorithms are not processor specific. Given that we are going to need to take timing information off of the crank and cam, probably with Hall effect sensors, and are eventually going to need to drive ignition coil packs and injectors: What driver circuitry is required to take a TTL load from a parallel port and drive an ignition coil pack or injector? What signal conditioning circuitry is required to take a Hall effect sensor and apply it to an interrupt line? What signal conditioning circuitry is required to take a Knock sensor and apply it to an interrupt line, and should you mask this interrupt during ignition? I would like to throw together a bit of a breadboard to try this stuff out before I use it to blow $300 worth of wirewrap to bits. I suspect that schematics for these circuits are available in some long lost periodical but searching through my stacks came up with nada. The computer geek magazines like to debate processors and generate faster fractals and the auto mags won't talk about electronic circuits unless you can pick them up as a black box. Thanks in advance, Andrei '62 Morris Traveller w/ 1350CC Cooper 'S engine '83 VW GTI 230,000 Km. and it keeps on going... -- Andrei Chichak | Information Systems agc@mercury.uah.ualberta.ca | University of Alberta Hospitals (403) 492 - 4431 (work) | 8440 112 Street Edmonton, Alberta (403) 492 - 3090 (fax) | CANADA T6G 2B7 From owner-diy_efi Thu Oct 13 00:28:18 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA21093; Thu, 13 Oct 94 00:28:18 GMT Received: from shiva.trl.OZ.AU by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA21086; Wed, 12 Oct 94 20:28:00 -0400 Received: by shiva.trl.OZ.AU id AA29909 (5.65c/IDA-1.4.4 for DIY_EFI@coulomb.eng.ohio-state.edu); Thu, 13 Oct 1994 10:27:45 +1000 From: Craig Pugsley Message-Id: <199410130027.AA29909@shiva.trl.OZ.AU> Subject: Re: Injector timing qns. To: DIY_EFI Date: Thu, 13 Oct 1994 10:27:44 +1000 (EST) X-Mailer: ELM [version 2.4 PL20] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 2710 Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI Dale Ulan writes: [...] > SAE Paper 810449, 'Mathematical Model of a Throttle > Body Fuel Injection System' by Robert Esperti is a particularly > good paper on this (although it gets mathematical). If you are > into reading papers, 810494 and 810495 are pretty good, as well. > Paper 790742, by G Czadzeck and R Reid of Ford, is a very good and > readable paper on the Ford CFI 5.0L 1980 cars. It covers most of > the 'twiddle factors' required to get the vehicle running properly. > Also, paper 800164 on the GM TBI system is nice easy reading. Neither > of these last two papers have any amount of hard math in them. Thanks - at last!!! some _solid_ info about how the algorithms work (I'm sick to death of the usual "and-the-rpm-combined-with-the-air-flow-meter -and-temperature-makes-it-go-gee-wizz" stuff found in most books on the subject. While I'm here, two more questions for comment: i/ What features does the HC11 have that makes it the 'processor of choice'? A-D, PWM, timers, watchdog, UART, high speed etc? Or is it more because it's an industry standard CPU? [I have limited experience with Z80 and 8051 processors]. It would seem logical to me to use a microcontroller than just a processor (Because I couldn't be bothered designing extra hardware when it's not needed, and a microcontroller is cheaper anyway) ii/ I want to make a 'gas analyser' with a Heated oxygen sensor. However, the idea is to make it so that the HEGO is in a bit of pipe /copper tube etc that can be put up the exhaust to 'sniff' the gas, and the reading displayed on a meter or just lean/stoic/rich LEDs. Obviously there will be the characteristic 'step' in the output voltage as it goes from lean to rich, but cost is the driving factor here. (IE no UEGO). The question is if a HEGO will work properly in this situation. i.e. all the heat required for operation is generated in the HEGO by it's resistor. Presumably I'll also need a fan or something to suck the gasses past the HEGO-will dilution be a problem? Any other forseeable problems? Exhaust pipe ____________________________ . . . .. . . . .. . . (.= Exhaust gas) .. . . . . . . . . . . . ___________________ . . . . ________________ | <--- Sampling pipe ____________________________ | | | | | | _________ (#=HEGO) | #----------| meter | | | | | (@=fan or other vacuum source |@| |_______| to suck gas past the HEGO) Cheers, Craig. From owner-diy_efi Thu Oct 13 04:32:31 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA21830; Thu, 13 Oct 94 04:32:31 GMT Received: from eigen.ee.ualberta.ca by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA21825; Thu, 13 Oct 94 00:32:28 -0400 Message-Id: <9410130432.AA21825@coulomb.eng.ohio-state.edu> Received: by eigen.ee.ualberta.ca (1.37.109.4/15.6) id AA05485; Wed, 12 Oct 94 22:32:26 -0600 From: Dale Ulan Subject: Re: Injector timing qns. To: DIY_EFI Date: Wed, 12 Oct 94 22:32:25 MDT In-Reply-To: <199410130027.AA29909@shiva.trl.OZ.AU>; from "Craig Pugsley" at Oct 13, 94 10:27 am Mailer: Elm [revision: 70.85] Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI > While I'm here, two more questions for comment: > > i/ What features does the HC11 have that makes it the 'processor of > choice'? A-D, PWM, timers, watchdog, UART, high speed etc? > Or is it more because it's an industry standard CPU? It has just the right peripherals for engine control. It also has the multiply and divide instructions, which are perfect for engine control software. Basically, it is the right processor for the job... and it's available. The 68F333 would be better, but good luck getting any... It has a UART, SPI (sync. serial), an 8-channel timer (3 ins, 5 outs), 8 channels of 8-bit A-D, and an on-board watchdog. As expected, some on-board RAM, some on-board EEPROM, and usually lots of space for external EPROM or Flash. I favor the 68HC11F1 version, since I have always been able to buy that one. -Dale From owner-diy_efi Thu Oct 13 05:15:42 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA22273; Thu, 13 Oct 94 05:15:42 GMT Received: from smtp.utexas.edu by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA22268; Thu, 13 Oct 94 01:15:36 -0400 Received: from mail.utexas.edu (mail.utexas.edu [128.83.126.1]) by smtp.utexas.edu (8.6.7/8.6.6) with ESMTP id AAA29049 for ; Thu, 13 Oct 1994 00:15:21 -0500 From: BigBrother@mail.utexas.edu Received: from [128.83.204.4] (slip-1-4.ots.utexas.edu [128.83.204.4]) by mail.utexas.edu (8.6.7/8.6.6) with SMTP id AAA15085 for ; Thu, 13 Oct 1994 00:14:48 -0500 Message-Id: <199410130514.AAA15085@mail.utexas.edu> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Thu, 13 Oct 1994 00:15:02 -0600 To: DIY_EFI Subject: finding 68F333's....... Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI writes: > and it's available. The 68F333 would be better, but good luck getting > any... Yeah, no kidding. Anybody out there seen any of these for sale. From anywhere? The 68F333 is awesome: 32-bit, 8 channel 10 bit A/D converter, TPU, .5k SRAM, 3.5k RAM, and best of all.... 64k of EEPROM. In one 160 pin package! From owner-diy_efi Thu Oct 13 14:11:21 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA23611; Thu, 13 Oct 94 14:11:21 GMT Received: from eigen.ee.ualberta.ca by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA23606; Thu, 13 Oct 94 10:11:17 -0400 Message-Id: <9410131411.AA23606@coulomb.eng.ohio-state.edu> Received: by eigen.ee.ualberta.ca (1.37.109.4/15.6) id AA07272; Thu, 13 Oct 94 08:11:14 -0600 From: Dale Ulan Subject: Re: finding 68F333's....... To: DIY_EFI Date: Thu, 13 Oct 94 8:11:13 MDT In-Reply-To: <199410130514.AAA15085@mail.utexas.edu>; from "BigBrother@mail.utexas.edu" at Oct 13, 94 12:15 (midnight) Mailer: Elm [revision: 70.85] Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI > > Yeah, no kidding. Anybody out there seen any of these for sale. > > The 68F333 is awesome: > 32-bit, 8 channel 10 bit A/D converter, TPU, .5k SRAM, 3.5k RAM, > and best of all.... 64k of EEPROM. In one 160 pin package! > Apparently, the 68332 is available... basically the same device but you need external memory. -Dale From owner-diy_efi Thu Oct 13 14:48:12 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA23821; Thu, 13 Oct 94 14:48:12 GMT Received: from grolsch-2.cs.ubc.ca by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA23816; Thu, 13 Oct 94 10:48:08 -0400 Received: (from ean@localhost) by grolsch.cs.ubc.ca (8.6.9/8.6.9) id HAA15402 for DIY_EFI@coulomb.eng.ohio-state.edu; Thu, 13 Oct 1994 07:48:06 -0700 X400-Received: by /PRMD=ca/ADMD=telecom.canada/C=ca/; Relayed; Thu, 13 Oct 1994 7:48:03 UTC-0700 Date: Thu, 13 Oct 1994 7:48:03 UTC-0700 X400-Originator: rodb@cs.ubc.ca X400-Recipients: non-disclosure:; X400-Content-Type: P2-1984 (2) X400-Mts-Identifier: [/PRMD=ca/ADMD=telecom.canada/C=ca/;941013074803] Content-Identifier: 1805 From: Rod Barman To: DIY_EFI In-Reply-To: <9410131411.AA23606@coulomb.eng.ohio-state.edu> Message-Id: <"1805*rodb@cs.ubc.ca"@MHS> Subject: Re: finding 68F333's....... Mime-Version: 1.0 (Generated by Ean X.400 to MIME gateway) Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI According to a Moto engineer who should know on the hc11 list, Moto is having problems with the EEPROM retention on `F333 and the HC16 variant. I would suggest using a '332 (available, I bought 15 of the early mask version cheap for CA$27each), an SPI ADC, and flash memory. I'm working on a couple different '332 projects here at work. I think it would be great to design a '332 based FI (oops, powertrain controller) board. Anybody care to spec it out? 8 injector drivers (2 X MC33293) 4 coil drivers (?) Octal Serial Switch (MC33298) ..... --rod. -- Rod Barman, IRIS NCE @ Laboratory for Computational Intelligence, University of British Columbia rodb@cs.ubc.ca From owner-diy_efi Fri Oct 14 01:58:03 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA00374; Fri, 14 Oct 94 01:58:03 GMT Received: from shiva.trl.OZ.AU by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA00340; Thu, 13 Oct 94 21:57:27 -0400 Received: by shiva.trl.OZ.AU id AA28956 (5.65c/IDA-1.4.4 for DIY_EFI@coulomb.eng.ohio-state.edu); Fri, 14 Oct 1994 11:57:20 +1000 From: Craig Pugsley Message-Id: <199410140157.AA28956@shiva.trl.OZ.AU> Subject: Re: Injector timing qns. To: DIY_EFI Date: Fri, 14 Oct 1994 11:57:19 +1000 (EST) X-Mailer: ELM [version 2.4 PL20] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 2291 Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI Hi there, A few days ago I asked this: >I've got a few questions regarding injector timing: > >i/ Does the timing of the injector relative to the timing of > the intake opening matter much?. IE if you've got the same > injector on time, but change the 'phase angle' relative to the > cam, will the power output vary much? > > Rewording, will power output change much between full sequential > and simultaneous injection, if you assume (as with L-Jetronic) > that the fuel can "Hang around" in the intake while the valve > is shut, or for optimum power should the fuel injector only be > turned on while air is flowing into the engine I did a bit of digging (actually, I was trying to find those SAE papers Dale was speaking of - with no luck). I found an SAE-like organisation's year book on automotive electronics. There was an article from the mid 80's (I lost the bit of paper that I wrote the exact reference on). Anyway, in a paper by J.H. Francis from Lucas, U.K. titled 'Electronic engine management for high speed competition engines' It is written about the Lucas '468' as used on a V6 rally car. It's got a few graphs which look like this: Peak torque (Nm) at 6000 RPM 338.0 | | 334.5 | ** | * ** 331.0 |**** ** *** | ****** ** 327.5 | ** | 324.0 | |_________________________ Injector valve closing angle. BDC |TDC | BDC |<------->| intake valve open. IE what they are saying is that they got max torque with the injector firing finishing about 2/3 of the way through the intake cycle. Conclusion: Timing IS critical for maximum performance. (Even though it's only 2-3% difference) There is also another graph showing fuel consumption. Above 6000 rpm, sequential and grouped injection use the same amount of fuel. Below 6000 rpm, the sequential uses about 3/4 of the fuel that grouped injection uses (According to the graph). Can someone please tell me what they think of my HEGO probe idea posted the other day? I might try it and let you know anyway. Cheers, Craig. pugsley@trl.oz.au