DIY_EFI Digest Wednesday, 10 January 1996 Volume 01 : Number 006 In this issue: Adjustable electronic ignition Re: Ford Sierra Cosworth ECU Prom RE: SDS EM-1 Re: Adjustable electronic ignition See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Adam Tate Date: Wed, 10 Jan 1996 09:34:54 +0800 Subject: Adjustable electronic ignition Just a quick question, My Holden Commodore runs a Buick 3.8 litre V6 and uses a crankshaft sensor for the ignition timing. What I want to do is vary the timing, preferably from inside the car. One way to change it, although being non-variable, would be to offset the sensor slightly to obtain a fixed advance or retard in the timing. What I would prefer however, is to intercept the signal before the ECM, and somehow modify it electronically to make it appear that it is advanced slightly. Can I do this with a simple capacitance type delay, or would I need to use a specialised circuit? Also, any ideas what the delay would have to be - milliseconds, nanoseconds ? Ideally I would like to have some sort of dash mounted box with an adjustable dial or something along those lines. All input is most appreciated. Adam Tate. [at@xxx.au] http://www.multiline.com.au/~atate/index.html ------------------------------ From: KMJMS@xxx.com Date: Tue, 9 Jan 1996 23:12:09 -0500 Subject: Re: Ford Sierra Cosworth ECU Prom This is all very interesting. Are your Ford Electronic engine controls the same as FoMoCo of Usa EEC IV system? I would be interested in seeing data about your Ford ECU proms. Kirk Davies ------------------------------ From: dn Date: Tue, 9 Jan 96 21:27:34 MDT Subject: RE: SDS EM-1 > I am interested in the info as to what you find.........thanks! > >Re: > > > >> Racetech Engineering SDS EM-1 I just got the brochure in the mail, unit is as follows: "D" unit includes: adjustable parameters: ECU FUEL - 250 RPM increments - 255 points LCD programmer MAP/TPS - 64 points Injector drivers AIR TEMP - 64 points TPS WTR TEMP - 32 points Temp Sensors STARTING - 32 points Wiring Harness ACCEL - 3 points Fuel Trim Ctrl CL LOOP - 5 points BOOST LIMIT REV LIMIT "E" unit adds Coil/amp IGN TIMING - 100 points Crank Sensor KNOCK CONTROL (OPT) Options: MAP sensor O2 sensor Knock Sensor (E only) PRICES: EM-1D EM-1E W/KNOCK 4 cyl $860 $1150 $1295 6 cyl $880 $1170 $1315 8 cyl $935 N/A - (available mid '96) Rotary $890 N/A All prices in $CDN, mult by .72 for $US The programmer looks nifty, has 2 gauge modes for monitoring, you can toggle back and forth between gauge and setup modes, as well as set all parameters with engine running. The reason I originally said the ignition control unit wasn't available yet is 'cause I was interested in the V8 unit... All in all, it looks interesting, one of the days I'm going to drop by this guy's place and see what it looks like "in the flesh". 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 @ + < __/ "Ain't no substitute for clock speed or compression ratio" ------------------------------------------------------------------------- ------------------------------ From: Craig Pugsley Date: Wed, 10 Jan 1996 16:38:24 +1100 (EST) Subject: Re: Adjustable electronic ignition > > Just a quick question, > My Holden Commodore runs a Buick 3.8 litre > V6 and uses a crankshaft sensor for the ignition timing. What I want to do > is vary the timing, preferably from inside the car. One way to change it, > although being non-variable, would be to offset the sensor slightly to > obtain a fixed advance or retard in the timing. What I would prefer however, > is to intercept the signal before the ECM, and somehow modify it > electronically to make it appear that it is advanced slightly. > > Can I do this with a simple capacitance type delay, or would I need to use a > specialised circuit? Also, any ideas what the delay would have to be - > milliseconds, nanoseconds ? Ideally I would like to have some sort of dash > mounted box with an adjustable dial or something along those lines. > According to the info I have (for a VN 1988 commodore with 3.8 V6 and GM P3 computer), there are 2 hall effect devices near the harmonic balancer that read pulses from 2 seperate rings. The outer ring has 18 pulses of equal spacing and the inner ring has 3 un-equal length slots & the computer counts how many of the 18 pulses occur in the length of the un-equal pulses to determine where the engine is. (It doesn't need to know if the cylinder's TDC is for the compression or for the exhaust stroke as it uses a wasted spark system). What this means is that electronically adjusting the timing would require microprocessor intervention, NOT a simple capacitor etc delay. you MIGHT be able to fool the micro by clocking the 3 pulse set into a FIFO device, and bump up the clock rate momentarily to get advance etc. but if you break your crank don't blame me. You might be able to do it by the fixed mechanical advance idea and letting the knock sensor tune to computer properly. (& this would be a LOT quicker & simpler to try) I am wondering why you want to do this anyway? I think the extra power you might gain would be less than if you used premium unleaded or a good exhaust system. Cheers, Craig. PS any suggestions for a good source of automotive connectors? ------------------------------ End of DIY_EFI Digest V1 #6 *************************** 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".