DIY_EFI Digest Wednesday, 17 April 1996 Volume 01 : Number 112 In this issue: Piston plug? OOPS of the day. Closed loop operation... Re: Speed Density SFI -possible? Injector spray cone angle, pulse width, timing Re: Ignition questions & the Nat semi Injector driver Re: type of eprom Re: fpga compilers Re: type of eprom Re: Piston plug? polar gap plugs Re: polar gap plugs Re: Ignition questions & the Nat semi Injector driver FW: Re: fpga compilers Re: type of eprom Re[2]: polar gap plugs Re: Closed loop operation... Re: Re[2]: Multi Spark Ignition... Address? Re: Multi Spark Ignition... Surface Gap Plugs Re: Ignition questions & the Nat semi Injector driver See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: einarp@xxx.no (Einar Sjaavik) Date: Tue, 16 Apr 96 11:18:57 CET Subject: Piston plug? >On the topic of spark plugs... has anyone seen the info on the new Saab >plug. Engineers replaced the standard plug with a single isolated >electrode then built up a special piston with a peak in the middle. The >peak acts as the ground, causing a spark to jump across the combustion >chamber. By changing timing they can change the effective plug gap as >well. Sounds like the best plug to date. How do they go about changing the timing _without_ changing the gap? I would imagine 40 degrees of advance would need a pretty hefty voltage to make the spark jump over to the piston. And what happens when the time is up for a plug change? "OK. That'll be four plugs, four pistons, and then a full engine teardown to change them. 'Have your wallet ready?" Was this invented about 16 days ago :-) - -- einarp@xxx.no ( Maserati Biturbo Spyder ) ------------------------------ From: einarp@xxx.no (Einar Sjaavik) Date: Tue, 16 Apr 96 10:55:10 CET Subject: OOPS of the day. >From: Andrew Dalgleish >Date: Fri, 12 Apr 1996 09:43:11 -0400 >Subject: RE: thermocouples and mixture. > >For someone who knows a lot about copyright laws, you don't seem to spell >too well : ) >their, electronic, illegally, material, counterfeit, definitely, category > >of..."? That includes your scanner. You have to get there permission first ^^^^^ Is that correct in Australia? :-) Regards Einar - -- einarp@xxx.no ( Maserati Biturbo Spyder ) ------------------------------ From: "Nietzsche is dead. -God" Date: Tue, 16 Apr 1996 08:25:13 EDT Subject: Closed loop operation... Right now, I'm running an open loop system (Haltech F3 - I know, it's an oldie) and I was wondering if anyone out there would know how easy it would be to convert this system to a closed loop system. The original Haltech has an input for an O2 sensor, buit it is striuctly for data logging purposes... or so I've been told. I was wondering if it is possible to do, and if so, how? If it isn't, then if I were to get a microcontroller (Intel 80196, Motorola 68HC16, etc...) Would I be able to use the maps that have already been created from using the Haltech... Speaking of closed loop operation, I'm having a difficult time uderstanding exactly how it works... is it still a lookup table with a correction factor for the O2 sensor reading, or is it an autonomous system where just the O2 sensor controls the whole thing? Thanks! --Mark Hofmann@xxx.edu http://linux.hartford.edu/~mark ------------------------------ From: orlin steven jared Date: Tue, 16 Apr 1996 08:55:39 -0400 (EDT) Subject: Re: Speed Density SFI -possible? > >Great. I'll have to write to them and see what they offer. What > >do you consider 'decent' vacuum? > > Lets say: idles below 60kpa (12") and will cruise at resonable speeds > below 70kpa (9"). > The main idea is, the more vacuum the better as the system operates > over a wider range and will deal with altitude changes better. That shouldn't be a problem. I'm looking to build a 502BBC with similar performance/displacement as my current ZZ3 350. And it gets 16" at idle. Except with the 502, I'll want a slightly more radical cam, to match up the fuel injection with and hopefully pull around 550-600HP with 10:1 compression and pump gas. My goal is to simply make as much power as possible with pump gas, AND try to get gas milege good enough for some high speed cruising. Now, correct me if I'm wrong, but I would think high vacuum would be more necessary with the SFI setup since you wouldn't have the fuel 'waiting' around in the port for the intake valve to open, as you would with the batch fire. On the other hand, the batch fire would probably work pretty well with a large duration race cam, and pretty low vacuum, right? > >Also, what is usually tuneable with these systems? spark map, injector > >timing, opening time, etc. ? I'm a real novice :-) > I think it would be great to be able to find a good race setting, and a good high speed cruise setting, and to have the capability to change the settings pretty much on the fly. (from a laptop). Steve ------------------------------ From: orlin steven jared Date: Tue, 16 Apr 1996 09:07:11 -0400 (EDT) Subject: Injector spray cone angle, pulse width, timing Here are a few questions hopefully some of the more experienced can help me out with.. I know some of these topics have been discussed, but I'm not sure if any conclusions or total agreements were reached. I am interested in what the benefits are to a particular injection cone angle, and to how injectors are usually aimed into the port. Are they usually aimed at the back of the intake valve, or as close as possible, or are they just aimed down into the flow stream? Is there any particular benefit to using two injectors, instead of one, at each port? Also, has there been any general consensus or guidlines on the optimum injector pulse width for a given application, or is this still the fun part of tuning? :) I guess I'm just looking for a general starting point or feel for what I should be doing in this area. How does the pulse width and line pressure tie in with the closed loop operation? Is it completely dependent (the pulse width) on the closed loop mixture adjustments, or is it tuneable? If so, I imagine it is tuneable for open loop? Finally, is there any general consensus about when to fire the injector (in a SFI setup) in relation to when the intake valve opens? I imagine this is probably also a trick of the trade. Thanks, Steve ------------------------------ From: Bill Lewis Date: Tue, 16 Apr 1996 09:08:59 -0400 Subject: Re: Ignition questions & the Nat semi Injector driver > Me too. This is only accurate at relatively low current flows where > the wire stays cool, though, because copper has a pretty high > temperature coefficient! There's a reason they use nichrome and other > strange alloys for power resistors... > - -Charles There is a good reason for nichrome, but that's not it. Nichrome is good because it can glow red hot in a normal atmosphere without oxydizing and burning up. Bill ------------------------------ From: gtk110@xxx.edu Date: Tue, 16 Apr 1996 09:34:25 -0400 Subject: Re: type of eprom >>It's from a fiesta Rs turbo '90 >>Do you know the pinout? > > >I've made this offer before and am happy to do it again. > >I will supply a decoder for any EECIV computer complete with a copy of the >ORIGINAL software in a 27256 for $100. You can then do what you want with >27256's and just plug them into the adaptor which plugs into the "service" >port on the back of the computer. > >I will also identify the full and part throttle fuelling and timing maps for >you. I won't identify boost limits, speed limits rev limits etc as they cost >me too much to develop. If you're interested, mail me. > I really do not understand what you're talking about with the decoder and a "27256", but could I use this with my MAS equipped '88 Mustang 5.0 (it's EECIV too)....what benefit would I gain (eg. what does this stuff do) Gannon "Gripping the wheel, his knuckles went white with desire...the wheels of his Mustang exploding on the highway like a slug from a .45... True death... 400 horsepower, maximum performance piercing the night... This is BLACK SUNSHINE!" ------------------------------ From: blane@xxx. Lane) Date: Tue, 16 Apr 1996 14:56:57 GMT Subject: Re: fpga compilers On Wed, 6 Mar 1996 23:18:39 -0600 (CST), you wrote: > >I've seen free versions of MACH and Lattice isp series FPGA compilers, >there's also some other free compilers I saw on a FPGA www site but none >seemed to be for the big FPGAs. I >don't know how the size of these FPGAs compares with big stuff from Altera >or Xilinx. Also I saw an ad for Cypress VHDL compiler for $99. > Cypress and Lattice have special $99 introductory packages. They include their compiler and a couple of the smaller chips, and a serial programmer for them. I don't have one yet, but have been looking at them for a bit now. Check out their web pages for more information. Brian - ------- ------- Embedded Systems Programmer, EET Student, Interactive Fiction author (RSN!) ============== 11 99 3D DB 63 4D 0B 22 15 DC 5A 12 71 DE EE 36 ============ ------------------------------ From: pjwales@xxx.net (Peter Wales) Date: Tue, 16 Apr 1996 11:01:27 -0400 Subject: Re: type of eprom >I really do not understand what you're talking about with the decoder and a >"27256", but could I use this with my MAS equipped '88 Mustang 5.0 (it's >EECIV too)....what benefit would I gain (eg. what does this stuff do) The Ford system is a weird setup which they have kept very much to themselves. A few companies have cracked it and can reprogram the computer. Hypertech probably were the first in this field and developed the procedure and others (including us) saw what they had done and figured out our own version of it. In a nutshell, the data lines are available at a connector on the rear of the computer. There is also a feed which disables the internal eprom. The problem was to convert the data coming from the Ford unit into something which could be changed and the obvious answer is an Intel type EPROM. As the early Ford units had 32k eproms, the size of the Intel device was obviously going to be a 27256. The challenge was to convert "Ford speak" to "Intel speak" and we used an Actel A1010 gate array to do it. It was just about big enough (which gives you DIY guys an idea of the size of the task you are setting yourselves) and the latest versions have external glue logic as well. A link to the power rail meant that by plugging it in you switched it on and by unplugging it, it went back to the internal eprom automatically. So we ended up with a small board which we can plug into the back of the EECIV computer (and EEC5 if it has the port) and it will allow us to plug in an ordinary EPROM and change the program. We have developed a device which will read the EEC files and have most of them on record so what I am offering is a device which will convert your EEC computer to a plug in chip computer, then you have the job of retiming it and refuelling it to get the best performance. It is only a converter to allow you to do the reprogramming, in itself will do nothing for your car. Peter Wales pjwales@xxx.net President Superchips Inc Chairman Superchips Ltd "Timing is everything" Superchips home page with all the answers http://www.superchips.com ------------------------------ From: orlin steven jared Date: Tue, 16 Apr 1996 11:10:43 -0400 (EDT) Subject: Re: Piston plug? > >On the topic of spark plugs... has anyone seen the info on the new Saab > >plug. Engineers replaced the standard plug with a single isolated > >electrode then built up a special piston with a peak in the middle. The > >peak acts as the ground, causing a spark to jump across the combustion > >chamber. By changing timing they can change the effective plug gap as > >well. Sounds like the best plug to date. > > How do they go about changing the timing _without_ changing the gap? > I would imagine 40 degrees of advance would need a pretty hefty voltage > to make the spark jump over to the piston. > > And what happens when the time is up for a plug change? > "OK. That'll be four plugs, four pistons, and then a full > engine teardown to change them. 'Have your wallet ready?" > > Was this invented about 16 days ago :-) This is a common idea, but it has many flaws, as you pointed out some above. Gap consistency is obviously the big one, since it will be continually varying depending on the timing advance of the engine. Just guessing, but I think this would cause a lot of variation in engine emissions. Especially since you would need a monster ignition system, capable of sending a spark across a very wide gap during lean conditions. Otherwise you would have lots of backfiring. But anyway, this brings up another question. How do you insure that the spark jumps to the piston anyways, instead of the side of the combustion chamber where the plug inserts? I ,also, don't see it happening. Steve ------------------------------ From: Jim Steck <72614.557@xxx.COM> Date: 16 Apr 96 11:16:41 EDT Subject: polar gap plugs >Surface gap plugs are the coldest plugs you can get. On the rating >engines at Autolite they can't even be made to pre-ignite. They >would also foul out pretty quickly after a few cold starts in >a street motor. Not necessarily . . . they were original equipment in Alfa Romeo 4 cylinders when the cars were still imported. Maybe the Autolite plugs were colder than the Lodge used in the Alfa. - -Jim Steck ------------------------------ From: orlin steven jared Date: Tue, 16 Apr 1996 13:29:27 -0400 (EDT) Subject: Re: polar gap plugs > >engines at Autolite they can't even be made to pre-ignite. They > >would also foul out pretty quickly after a few cold starts in > >a street motor. > > Not necessarily . . . they were original equipment in Alfa Romeo 4 cylinders > when the cars were still imported. Maybe the Autolite plugs were colder than > the Lodge used in the Alfa. Possibly, but I'd be interested to know exactly what plugs were OEM for those engines, to see exactly how cold they are. I don't think they used a standard surface gap, but I could be wrong. Also, the alfa's may have leaner starts not so hard on the plug.. Steve ------------------------------ From: cmorris@xxx.com (Charles) Date: Tue, 16 Apr 1996 15:20:10 -0700 Subject: Re: Ignition questions & the Nat semi Injector driver I originally wrote: >> This is only accurate at relatively low current flows where >> the wire stays cool, though, because copper has a pretty high >> temperature coefficient! You wrote: >There is a good reason for nichrome, but that's not it. >Nichrome is good because it can glow red hot in a normal atmosphere >without oxydizing and burning up. > >Bill > That may be true, but I still disagree with you about using copper. Try it and see! If you make your shunt for 50 mv, 20 amps is one watt; this may be OK if your shunt is physically large enough. On the other hand, if you prefer 200 or 250 mv drop... 4-5 watts... a small mass of copper wire _will_ get warm enough to significantly affect the accuracy. You can see the meter changing as the shunt heats, whereas the reference ammeter in series is not changing. - -Charles ------------------------------ From: john carroll Date: Tue, 16 Apr 96 16:26:51 PDT Subject: FW: Re: fpga compilers I purchased the Lattice intro kit to meet a definite need and was able to turn out a program and sample device that met my customers needs with a couple evenings work. I did have to build a small PC board and buy an expensive ZIF socket in order to develop and check out my work. I think that it is entirely reasonable to develop software on the target device. John carroll jac@xxx.us - -------------------------------------------------- On Tue, 16 Apr 1996 14:56:57 GMT Brian C. Lane wrote: >On Wed, 6 Mar 1996 23:18:39 -0600 (CST), you wrote: > >> >>I've seen free versions of MACH and Lattice isp series FPGA compilers, >>there's also some other free compilers I saw on a FPGA www site but none >>seemed to be for the big FPGAs. I >>don't know how the size of these FPGAs compares with big stuff from Altera >>or Xilinx. Also I saw an ad for Cypress VHDL compiler for $99. >> > > Cypress and Lattice have special $99 introductory packages. They include >their compiler and a couple of the smaller chips, and a serial programmer >for them. I don't have one yet, but have been looking at them for a bit >now. > > Check out their web pages for more information. > > Brian > >------- -------------------- ------- > Embedded Systems Programmer, EET Student, Interactive Fiction author (RSN!) >============== 11 99 3D DB 63 4D 0B 22 15 DC 5A 12 71 DE EE 36 ============ > - ----------------------------------------------- jac@xxx.us john carroll ------------------------------ From: pjwales@xxx.net (Peter Wales) Date: Tue, 16 Apr 1996 21:26:18 -0400 Subject: Re: type of eprom >Thanks for the full explanation. I do have a question, which others >may be interested in. > >The EECIV , of which I have one of, Has a learning mode to compensate >for changes in parts over time and to fine tune the cruise mode A/F. >Does your adapter change any of the modes, or just the base settings. >I've read conflicting reports about this since about 88, when the >adapters first started popping up. Good question! First let me explain the learning mode. If the optimum fuel number for a certain conditions in the particular car is 80H and the program contains the number 78H then the computer corrects the fuelling number by reading the oxygen sensor and increasing the fuel until the engine is at stoichiometric. Then the fuelling number has risen to 80H and the computer records a difference of 08H in its Keep Alive Memory. The next time it gets the same conditions it adds the correction to the main number and gets the correct fuelling number quickly. This allows the engine to tune itself more quickly. If we fit a chip, then the fuelling on part throttle will be unchanged, simply because the oxygen sensor overrides all the changes we make and all we can do is to slow down the engines time to perfect tune, which the memory will soon fix anyway. On full throttle the correction is not used and the system goes open loop. So, fitting a chip will not affect the memory and it may take a little time for the computer to optimise itself by learning about the car, but it should have happened in 20 miles or so. When we develop a chip, we have to clear the memory to ensure we don't program the car with a built in correction factor and we do power runs so fast the system has no time to learn. Hopefully the the memory correction will never be used on that car, but will allow other cars to optimise themselves. As the cars age, they tune themselves to adapt for increased wear and carbon build up. I hope that answers the question Peter Wales pjwales@xxx.net President Superchips Inc Chairman Superchips Ltd "Timing is everything" Superchips home page with all the answers http://www.superchips.com ------------------------------ From: dzorde@xxx.au Date: Wed, 17 Apr 96 10:34:35 Subject: Re[2]: polar gap plugs My 2 cents worth. The plugs used in Alfa boxer motors are standard ring plugs, 1 center electrode and 4 ground electrodes. They are made by Golden Lodge (hope it is spelled correctly), I think the Alfa 33 uses a 25HLY, but don't ask what the temp is like. Dan dzorde@xxx.au ______________________________ Reply Separator _________________________________ Subject: Re: polar gap plugs Author: diy_efi@xxx.edu at INTERNET Date: 4/17/96 8:58 AM > >engines at Autolite they can't even be made to pre-ignite. They > >would also foul out pretty quickly after a few cold starts in > >a street motor. > > Not necessarily . . . they were original equipment in Alfa Romeo 4 cylinders > when the cars were still imported. Maybe the Autolite plugs were colder than > the Lodge used in the Alfa. Possibly, but I'd be interested to know exactly what plugs were OEM for those engines, to see exactly how cold they are. I don't think they used a standard surface gap, but I could be wrong. Also, the alfa's may have leaner starts not so hard on the plug.. Steve ------------------------------ From: TAR Date: Tue, 16 Apr 1996 22:24:14 -0600 (MDT) Subject: Re: Closed loop operation... Mark, I am in the preliminary stages of EFI design using a M68HC11. I am going to get the thing running open loop first and add O2 and knock control once all the maps are correct. As far as I know, closed loop operation on most factory ECU's consists of a look-up table with correction from the O2 sensor. Usually, pulse width correction does not exceed around 10% (somebody correct me if I'm wrong pls! I am still looking into cracked factory source code and SAE references to figure this one out too). I figure the closer you can get your look-up table (ie: the less the O2 sensor has to adjust AFR), the better your engine will run, especially in Limp-Home-Mode or in the event of an O2 sensor failure. any feedback? Todd- On Tue, 16 Apr 1996, Nietzsche is dead. -God (aka Mark Hofmann)wrote: > Speaking of closed loop operation, I'm having a difficult time uderstanding > exactly how it works... is it still a lookup table with a correction factor > for the O2 sensor reading, or is it an autonomous system where just the > O2 sensor controls the whole thing? > --Mark > Hofmann@xxx.edu > http://linux.hartford.edu/~mark ||||||||||||||||||||||||||||||||||||||||||||| Todd Ratke e-mail: tratke@xxx.ca -or- ratke@xxx.ca ||||||||||||||||||||||||||||||||||||||||||||| ------------------------------ From: FparkerL98@xxx.com Date: Wed, 17 Apr 1996 01:25:01 -0400 Subject: Re: Re[2]: Multi Spark Ignition... Address? I ahve been out of town and this is my 1st attempt a email from aol. Send your address to " fparker@xxx.edu " and I will mail to you when I return. frank ------------------------------ From: FparkerL98@xxx.com Date: Wed, 17 Apr 1996 01:27:44 -0400 Subject: Re: Multi Spark Ignition... OK, will do. Out of town now @xxx. I would like to do similar with L98 powered S-10 with DFI fuel and ign control frank ------------------------------ From: ShempMoDin@xxx.com Date: Wed, 17 Apr 1996 01:40:48 -0400 Subject: Surface Gap Plugs I don't know if someone already posted this info or not - if so, forgive me. Regarding surface gap plugs, I know for a fact that Alfa Romeos came from the factory with such plugs, Golden Lodge plugs, manufactured by Lodge. Replacements can be found if you look for them, one supplier is International Auto Parts (1-800-726-0555). They come in two heat ranges, one is designated HL for "normal speed driving", the other is designated 2HL, for "high speed driving". If you're interested, the IAP part numbers are HL and 2HL, respectively, and they sell for $4.75 each regardless of heat range. -Paul Witek ------------------------------ From: arthurok@xxx.com (ARTHUR OKUN ) Date: Tue, 16 Apr 1996 23:19:31 -0700 Subject: Re: Ignition questions & the Nat semi Injector driver i have a cheap digital mutimeter that uses a piece of heavy copper wire as a 10 amp shunt and i think its accurate to 1.5 % ------------------------------ End of DIY_EFI Digest V1 #112 ***************************** 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".