DIY_EFI Digest Thursday, 22 August 1996 Volume 01 : Number 239 In this issue: Re: My DIY EFI Re: Slide Throttles Re: '97 Corvette engine, DIS Re: My DIY EFI linear EFI Re: My DIY EFI Re: DIY_EFI for OSU!!!!!!!!!!!! FULL EMISSIONS VEHICLES Direct Ignition EFI musings Re: Slide Throttles Re: EFI musings Re: Slide Throttles Re: ZEV / REV Re: My DIY EFI Re: EFI musings Re[2]: Truck parts Dynamometer. re: Re: Slide Throttles Re: linear EFI Re[2]: Zero Emissions Vehicle (was Electric Veh.) re: Direct Ignition Re: EFI musings Re: Slide Throttles Re: Slide Throttles Re: EFI musings Re: Re[2]: Zero Emissions Vehicle (was Electric Veh.) Re: '97 Corvette engine, DIS Re: EFI musings See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: "Bosch, AN, Andrew, Dr" Date: Wed, 21 Aug 1996 12:30:47 UTC-2 Subject: Re: My DIY EFI I even had a dash > mounted pot for changing overall ignition timing. Kinda like being able to > turn the distribuator while driving. So I have the real experience to say > that the simple system using just a few pots will work. Out of curosity, I > even cloned the system in the analog environment. It only used a few op > amps and some resistors. With a little work, I could of made it temperature > stable. I took the simple system a bit further and am even selling it > retail. To the people that have used it, they like it. I have had one on > my own car for over 2 years now. So I must agree, even though the fancy > networks and programing languages can make for interesting extras, They are > not needed to have a functional EFI system. Remember the KISS principle. > Could you give me more info about your system, and the cost of it? Thanks. Andrew Dr A. N. Bosch Physiology Department/ Sports Science Institute University of Cape Town Medical School P. O. Box 115 Newlands 7700 South Africa ------------------------------ From: "Edward C. Hernandez" Date: Wed, 21 Aug 1996 08:24:38 -0400 Subject: Re: Slide Throttles Paul Shackleton wrote: >slide throttles... pros & cons compared with butterfly throttles? One advantage is zero flow loss when a slide throttle is wide open: there is nothing left in the flow path. A con would be constructing one that doesn't leak with the room available in the engine bay; it has to slide SOMEWHERE. I have seen barrel throttles, which is basically 100% shaft with a hole the size of the bore, sort of like certain kinds of hydraulic/pneumatic valves. They don't need that much room and also provide zero flow loss at WOT. You can DIY anything given enough patience, time, money... - -- Ed Hernandez Ford Motor Company ehernan3@xxx.com ------------------------------ From: txhartma@xxx.com (Terry Hartman) Date: Wed, 21 Aug 1996 07:58:26 -0500 Subject: Re: '97 Corvette engine, DIS > > From: dave.williams@xxx.us (Dave Williams) > > - -> Are the rumors true, Direct Ignition on the '97 Corvette 5.7l LT1? > - -> Are there any technical tidbits available? Feed me info ...please! > > I haven't seen anything about why they went to eight coils instead of > four dual coils. I know the Ford 4.6 uses different spark plugs for > each side of a dual coil, but most engines don't bother. Supposedly - this is to help with individual cylinder timing. If one of the two knock sensors picks up detonation, only that cylinder's timing will be affected... > > The LS-1 is a completely new Chevrolet V8 engine with no parts > interchanging with the old small block, or the LT5 for that matter. > 3.9x3.6 bore/stroke, four bolt heads, evenly-spaced ports, gerotor oil > pump driven off the front of the crank, thrust main now on center > bearing, etc. > There ARE some parts that interchange, although they are minor. The hydraulic roller lifters and I believe rod bearings.... later, T. ------------------------------ From: cloud@xxx.edu (tom cloud) Date: Wed, 21 Aug 1996 08:25:13 -0500 Subject: Re: My DIY EFI >> stable. I took the simple system a bit further and am even selling it >> retail. To the people that have used it, they like it. I have had one on >> my own car for over 2 years now. So I must agree, even though the fancy >> networks and programing languages can make for interesting extras, They are >> not needed to have a functional EFI system. Remember the KISS principle. >> >Could you give me more info about your system, and the cost of it? > >Thanks. > >Andrew > > Dr A. N. Bosch >Physiology Department/ Sports Science Institute >University of Cape Town Medical School >P. O. Box 115 >Newlands 7700 >South Africa Ditto Tom Cloud ------------------------------ From: cloud@xxx.edu (tom cloud) Date: Wed, 21 Aug 1996 09:33:57 -0500 Subject: linear EFI >My 2 cents on the simple pot based efi system. > >There is a lot of talk out there, but has any one actually made one of these >systems? I have!!. [ snip ] >David J. Doddek |pantera@xxx.com >Owner SGD Electronics & Development Engr for Caterpillar |h 309 685-7965 >Formula SAE Team Sidewinder 94-95 |w 309 578-2931 >89 T-bird SC, 69 Fairlane w/SGD EFI |fx 217 428-4686 >74 Pantera w/Electromotive Tec-II Twin turbos and Nitros | >Hey, If you are going to go fast, go REEEAAL FAST. | > David, I just sent you a "ditto" re your experiences with above- referenced controller you've done and thought I would elaborate. I am the reprobate that brought a simple analog or hybrid analog - digital system into the discussion and have endured some castigation for my backward ways as well as some agreement. To answer your question, yes, I have such a system. It is the Holley aftermarket EFI. Has pots for IDLE, MIDRANGE, POWER, ACCELERATOR PUMP, and CHOKE and that's about it -- with the exception of a switch on the PCB for small or large block engine. It uses only TPS, RPM and engine temp as controller inputs and uses two injectors for ~650 cfm. I would like to do better (thought I'd find a Ford controller, modify the PROM and retrofit it and EFI manifold, injectors and rails to my pre-EFI Bronco). I work with an engineer who designed an EFI for racing jet skis using hybrid analog / digital (his injector pulse was timed by a XTAL clock driving a pre-loaded down counter, etc.) He has also worked closely with a supercharger manufacturer here in Austin, TX on FI systems. He has supported me in thinking that, unless trying to achieve zero emissions, simplicity (i.e. no micro-controller) is the best. I observe that analog, though the building block everything else is built upon, is not being taught our new engineers. I guess I consider myself fortunate to have worked (as a kid) with "thermionic emission devices" otherwise called vacuum tubes, analog semiconductors, and then main frames, minis and micro- computers. Like most, I love the 'neatness' of digital, but I've learned from hard knocks that sometimes a relay is preferable to an SSR (solid state relay) and digital is not necessarily all it's cracked up to be. Analog can be unstable (temp and oscillation), but digital has sampling, aliasing, etc. errors and loss of resolution in conversion to and from digital. (Besides if it's too cold or hot for an analog system, this old boy's staying inside!) The cost of doing a micro- controller system can be overwhelming, unless you have all the stuff at work. One needs a computer, assemblers, dis-assemblers, high speed oscilloscopes, maybe logic analyzers and ICE's, logic probes, and lots and lots of printer paper. (Programmers get rusty zippers and yellow sneakers, I hear -- just gotta compile one more time.) One can do the analog design with a 20 MHz scope, a triple output power supply, and a proto board. Of course, a copy of Electronic Workbench or such to do a computer simulation would be helpful. An advantage of the digital: it can do data logging and can even be taught to 'learn' standard system conditions, thereby sort of self calibrating or adjusting itself -- but this becomes a serious programming effort. Been there, done that! I'm getting old enough where I'd like to use it in this life. The digital system could be wire wrapped. The analog system could be soldered. Else one would need to lay out a PCB and get it etched, drilled and plated. Well, I've rambled long enough. All in all, my engineering self really wants to do this digital, but my 4WD self really wants to just get to the mountains, and I can't help but believe that the simple hybrid or pure analog path is 98% as effective as the pure digital with probably 10% the development time and cost! (Like you, I've done systems both ways -- just have never done EFI and have joined this group to find out more. The main obstacle I perceived is the EGO, which appears to be useful but not exact, which really offends and exasperates my technical side. SO: you seem to have done it!! Please share with us hungry souls what you've done. Thanks, Tom Cloud Electronics Department Austin Community College 11928 Stonehollow Austin, Texas 78758 ------------------------------ From: Robert Van Zant Date: Wed, 21 Aug 1996 10:15:08 -0500 (CDT) Subject: Re: My DIY EFI > >Could you give me more info about your system, and the cost of it? > Ditto Me three. bob rvanzant@xxx.net ------------------------------ From: tom sparks Date: Wed, 21 Aug 1996 10:31:01 -0500 Subject: Re: DIY_EFI for OSU!!!!!!!!!!!! At 03:15 8/19/1996 -0700, you wrote: >Hello, > > I was searching the FSAE pages and I found this address concerning advice on >building your own EFI system. I thought it curious that we have someone here at ohio >state who is knowledgeable about EFI and how to build them and has yet to contact the >home team. We at OSU FSAE are very interested in this subject and would like to >discuss it with you. > My name is Neil Fife and I am motor devopment leader here at Ohio >State. I can be reached at The Center for Automotive Research ph#688-4084 during the >day. My E-mail is fife.5@xxx. > Looking forward to your reply, > Neil F. Fife > > Neil: Check out Circuit Cellar issues 62,63, and 64 for a series of articles for the fuel and ignition systems for an FSAE car from Rensselaer Polytechnic Institute. The articles were written by Ed Lansinger, a computer systems engineer who worked on the Cadillac Northstar powertrain control software. I think you'll find it helpful! Best regards, Thomas Sparks ------------------------------ From: tom sparks Date: Wed, 21 Aug 1996 10:37:56 -0500 Subject: FULL EMISSIONS VEHICLES I've got an idea. Why don't we use the DIY-EFI list to talk about DIY-EFI. WHAT A CONCEPT! Imagine staying on topic! Best regards, Thomas Sparks ------------------------------ From: brewer@xxx.com (John Brewer) Date: Wed, 21 Aug 1996 10:49:16 -0500 Subject: Direct Ignition I saw earlier today where Terry Hartman, in a post, made reference to the new Corvette using eight coils and perhaps direct ignition. My nomenclature is still coming up on the learning curve and I was wondering what direct ignition is? I hope it is not an idea I have been kicking around in my head for a few weeks now- then again if it is, I guess it means it was a good idea even if I was beaten to the punch! John Brewer "Any man who would trade liberty for security deserves neither." - Ben Franklin ------------------------------ From: "Edward C. Hernandez" Date: Wed, 21 Aug 1996 12:06:43 -0400 Subject: EFI musings Although I, too, am a fan of KISS(the phlisopahy, not the group), and a tightwad, I am also a big gadget fan. This means I often end up arguing with myself(engineers argue with anyone, inluding no one) when considering about getting something for my car: how does work, does it actually do what's claimed, is it worth the money, can I build it for less(money, not time and trouble). Therefore, I still drive a 33 year old, 2 ton, carbuereted, distributed, 2 valve, cast iron 2 speed behemoth that is still woefully out of touch with today's technology. But it runs 16.7s @ 84mph in the 1/4, gets almost 15 mpg, and has potential to run much faster with little $, and gets lots of looks. So what? Here's the dangerous question: in light of the recent discussion on analog vs digital EFI, and in the spirit of engineers taking things to the extreme, why not stick to carburetors(ignore spark control for a moment)? Yes, I am aware that this is an EFI list. But some very good points were made about what EFI can do vs what the DIYer needs it to do, and what sparked(pun intended) my question was a description of how both analog and digital systems figure out how much fuel to provide, why they might have to be trimmed/adjusted/calibrated, etc(even after you get it working at one point in time), which eventually led to KISS and analog/trimmming pots vs sophisti-digital, so I take it one step further. Don't get me wrong, I still lust for an EFI on my car, and I am still waiting to hear back from the guy who installed the Edelbrock #3500. But, in one page or less, what do you need and why not carbs? - -- Ed Hernandez Ford Motor Company ehernan3@xxx.com ------------------------------ From: Todd Knighton Date: Wed, 21 Aug 1996 09:32:25 -0700 Subject: Re: Slide Throttles Paul, Another disadvantage to slides is on turbo motors. One surge, or when you slam the throttle closed, they tend to stick closed because of the massive pressure placed on top of them. Whereas the butterflies offset the pressure equally on both sides of the shaft. Barrel throttles give very strange low flow characteristics, but do have very nice flow at wide open. They are hard to seal as well. The Oldsmobile Aerotech that set all the land speed records used it. But they said for emmisssions stuff it wouldn't work because of the leakage. Todd Knighton Protomotive Engineering Edward C. Hernandez wrote: > > Paul Shackleton wrote: > > >slide throttles... pros & cons compared with butterfly throttles? > > One advantage is zero flow loss when a slide throttle is wide open: > there is nothing left in the flow path. A con would be constructing one > that doesn't leak with the room available in the engine bay; it has to > slide SOMEWHERE. I have seen barrel throttles, which is basically 100% > shaft with a hole the size of the bore, sort of like certain kinds of > hydraulic/pneumatic valves. They don't need that much room and also > provide zero flow loss at WOT. You can DIY anything given enough > patience, time, money... > > -- > Ed Hernandez > Ford Motor Company > ehernan3@xxx.com ------------------------------ From: atsakiri@xxx.com Date: Wed, 21 Aug 96 12:32:23 -0400 Subject: Re: EFI musings [big snip] > But, in one page or less, what do you need and why not carbs? Uh oh, documented requirements. Doh! Anthony Tsakiris tsakiris@xxx.com - --------------------------------------------------------------------------- The opinions expressed are my own and not necessarily those of my employer. ------------------------------ From: "Michael T. Kasimirsky" Date: Wed, 21 Aug 1996 14:19:49 -0400 (EDT) Subject: Re: Slide Throttles On Wed, 21 Aug 1996, Todd Knighton wrote: > Paul, > Another disadvantage to slides is on turbo motors. One surge, or when > you slam the throttle closed, they tend to stick closed because of the > massive pressure placed on top of them. Whereas the butterflies offset > the pressure equally on both sides of the shaft. Wouldn't engine vacuum also have a similar effect as well? I assume you'd want a push-pull cable system to prevent this. Has anyone here successfully built a slide throttle set-up? How'd you do it? > Barrel throttles give very strange low flow characteristics, but do > have very nice flow at wide open. They are hard to seal as well. The Yeah, but parts are available at the hardware store in the plumbing department.... :-) Michael T. Kasimirsky ----> mtk@xxx.edu Days: Staff Engineer or mk4u@xxx.edu ASTM Test Monitoring Center Phi Gamma Delta, Nights: 1992 Suzuki GSX-R750 Pilot NRA Life Member, AMA Member 1991 Suzuki GSF400 Bandit Mechanic DoD #1848 ------------------------------ From: Kalle Pihlajasaari Date: Wed, 21 Aug 1996 21:16:20 +0200 (sat) Subject: Re: ZEV / REV Hi All, > I used to work at DEMI as a chemist doing ZEV battery development > (zinc air technology). DEMI is no longer around, don't know if anyone > picked up the technology. Our local Council for Scientific and Industrial Research (CSIR) did development work on the Zinc Air batteries and one of the big German electrical companies (AEG I think) bought the technology and went into pilot production last year with proposals for a full scale plant in Germany for Electric Vehicle use. Have heard nothing in the last while though. How about a quick 2 sentence explanation of the technology in Zinc Ait Cells (what is different about them) always wondered what the fuss was about. What I have always wanted to see is a (leathal ?) Hydrogen Oxygen car with a simple 2 stroke motor and simply pressure controlled injectors that let the gas in from balanced O2 and H2 galleries into the cylinder as the last of the steam escapes from the exhaust port and the pressure drops, closing automatically when the piston rises. This would simplify the problem of the injectors that has everybody so concerned. One would get zero emmisions except for water and either H2 or O2 (depending on the mix, adjustable with a lambda sensor possibly) with perhaps early or late ELECTRONIC ignition control to get more or less power and some way or adjusting the gallery pressure or the injector flow rate (difficult with H2 but perhaps possible). Are there any technical sources on the EFI systems used in older MB 450 engines, they have analog brain which is a Bosh unit I think and a friend of mine has asked if I can modify this to generate timed injection for the V8 as at the moment it is a proportional system with only 2 phases for all 8 injectors. Is there any point and do I just take the pulse width for the current revolution and delay the start until the correct injectors turn has come and then hold the injector open when the valve is open for the same time it would have done anyway ? I was told that there were 2 pulses on each set of 4 injectors per rev (or was it one per 2 revs) is this right or is it a random unsynchronised dutycycle that just meters/proportions the fuel? Cheers, great if somewhat noisy and verbose list. - -- Kalle Pihlajasaari kalle@xxx.za Interface Products Box 15775, Doornfontein, 2028, South Africa +27 (11) 402-7750 Fax: +27 (11) 402-7751 ------------------------------ From: Chris Morriss Date: Wed, 21 Aug 1996 19:02:21 +0100 Subject: Re: My DIY EFI In message <9608210045.AA07730@xxx.com>, David Doddek writes >My 2 cents on the simple pot based efi system. > >There is a lot of talk out there, but has any one actually made one of these >systems? I have!!. I first built an 8085 based system in college and used >the idea of controlling the main fuel curve with pots. I even had a dash >mounted pot for changing overall ignition timing. Kinda like being able to >turn the distribuator while driving. So I have the real experience to say >that the simple system using just a few pots will work. Out of curosity, I >even cloned the system in the analog environment. It only used a few op >amps and some resistors. With a little work, I could of made it temperature >stable. I took the simple system a bit further and am even selling it >retail. To the people that have used it, they like it. I have had one on >my own car for over 2 years now. So I must agree, even though the fancy >networks and programing languages can make for interesting extras, They are >not needed to have a functional EFI system. Remember the KISS principle. > Yes I have made a fuel injection controller using analog techniques. It was a simple M.A.P. sensed system giving one injection per revolution with the fuel quantity determined by M.A.P. and water temp. I had a pot to set offset and one to set gain. The offset pot was used to set the idle mixture, and the gain pot to set max torque mixture. I had a differentiator circuit driven from the throttle pot to give a richer mixture on acceleration. It was tried on a 1 litre Hillman Imp engine using Weber alpha injector housing elbows mounted on a twin 40DCOE manifold. A home made glass-fibre plenum chamber fed the four inlet runners with the airflow control by a single throttle body. It worked remarkably well. When I get the old Clan Crusader back on the road I'm going to do a PCB for the circuit. (The Clan is a little known Imp engined UK GRP sportscar) I've only been on this list for 2 days, so please forgive me if this topic has been covered hundreds of times before. Bye, - -- Chris Morriss ------------------------------ From: "Tony Bryant" Date: Thu, 22 Aug 1996 08:34:38 +1200 Subject: Re: EFI musings > Don't get me wrong, I still lust for an EFI on my car, and I am still > waiting to hear back from the guy who installed the Edelbrock #3500. > But, in one page or less, what do you need and why not carbs? In short, I need max power, easy adjustability, drivability, and to be affordable. Carbs don't flow as well as throttle bodies Carbs (for my application) are worth $1500 as opposed to the $300 for my EFI+Ignition Carbs either don't flow enough at full flow, or are hopeless at idle. Carbs aren't adjustable while driving. Carbs don't provide a ignition, my EFI box does (thereby saving me US$600 for a HPV-1 or similar). Carbs don't provide a data logging system, my EFI box does. Carbs suffer in High-G cornering or acceleration. *********************************************************** * "Insanity is the only sane response to an insane world" * * >> bryantt@xxx.nz << * *********************************************************** ------------------------------ From: wmcgonegal@xxx.ca Date: Wed, 21 Aug 96 17:55:27 EST Subject: Re[2]: Truck parts Dynamometer. >What really is involved in putting together a dynamometer - either >chassis or engine? Building a chassis dynamometer is not a trivial task. I have been involved with designing and building complete chassis dynamometers at our facility. Building the rolls is a large task. They have to be machined on large lathes and balanced. If you go with small diameter rolls they must be carefully balanced as they will be spinning faster then large rolls. Our experience with chassis dynamometers is that they are not suitable for making horsepower measurements (we use them for emissions work). The tires slip on the rolls at higher powers, and there is a lot of energy lost by the tires heating up as they deflect at the roll surface under sustained high load. With either a chassis or engine dynamometer you require a power absorption unit (PAU) if you want to maintain a constant speed. Some have been suggested in previous postings, including the eddy current style PAUs "Telma" and other brakes. One has to remember that all of the power coming out of the engine/vehicle has to be dissipated somehow. To continuously run at a high power output may require a large body of cooling water. One way we get around this with some of our engine and chassis dynamometers is to use regenerative DC motors as PAUs. The DC motors operate as generators to absorb the power and a power controller converts it to AC power which is fed back to the power grid. The cost of such a system is well beyond that of a DIYer. Another style of PAU that is used is the water brake. It consists of a rotor that has vanes on it that rotates in an enclosure. There is another set of vanes on the enclosure which are stationary. Water is in the enclosure, and by varying the level of water in the enclosure, the load can be changed. There is also a heat exchanger built into the enclose which uses water to keep the unit below a set temperature. The entire enclosure can rotate about the input shaft axis and is held in place by a load cell which is used to measure force and calculate torque. For very small engine testing we have set up an alternator to be used as a PAU. The load is changed by altering the alternators field current. The electrical energy that is created is dissipated in a bank of resistors. Again, force is measured with a load cell. We also have set up PAUs that are essentially hydraulic pumps. The oil is circulated by a pump through a heat exchanger and a valve in the circuit which is adjusted to vary the load by restricting the flow. It may be possible to build a hydraulic (oil or water) PAU out of a torque converter from an automatic transmission. Of course you have to keep it cool somehow. I have seen motorcycle dynamometers which consist of a large roll that has a lot of inertia. Knowing the inertia of the roll and by measuring speed and the rate of acceleration, you can calculate power. I think the easiest way for a DIYer to calculate power output from a vehicle is (as mentioned in other postings) to accelerate on a flat stretch of road while recording speed versus time. From this acceleration can be calculated. Power is calculated as Vehicle Mass * Acceleration * Speed. If kg, meters/second squared, and meters/ second are used the result is in Watts. Sorry for the length, I just had to say it. Will McGonegal Electrical Engineer Mobile Sources Emissions Division Environment Canada wmcgonegal@xxx.ca ------------------------------ From: SRavet@xxx.com Date: Wed, 21 Aug 96 16:26:35 CDT Subject: re: Re: Slide Throttles Todd Knighton Wrote: | | Paul, | Another disadvantage to slides is on turbo motors. One surge, or when | you slam the throttle closed, they tend to stick closed because of the | massive pressure placed on top of them. Whereas the butterflies offset | the pressure equally on both sides of the shaft. | Barrel throttles give very strange low flow characteristics, but do | have very nice flow at wide open. They are hard to seal as well. The | Oldsmobile Aerotech that set all the land speed records used it. But | they said for emmisssions stuff it wouldn't work because of the leakage. | | Todd Knighton | Protomotive Engineering OK, what is a slide throttle? I thought it was simply a "cover" that slides over a "hole". But that wouldn't tend to stick closed. so what is it? - --steve Steve Ravet sravet@xxx.com Baby you're a genius when it comes to cooking up some chili sauce... ------------------------------ From: cloud@xxx.edu (tom cloud) Date: Wed, 21 Aug 1996 17:17:51 -0500 Subject: Re: linear EFI One thing just struck me -- the analog EFI I have is throttle body (TBI) not port injection. Haven't thought about the complexity of doing TPI with analog controller -- maybe use a flip-flop to switch from one bank of injectors to the other and pulse half at a time. That's what the system on my Ford F-150 does now, except it's digital. ------------------------------ From: wmcgonegal@xxx.ca Date: Wed, 21 Aug 96 18:17:42 EST Subject: Re[2]: Zero Emissions Vehicle (was Electric Veh.) >Someone with a heavily modified engine would merely use more alcohol, >not add to any pollution problem (except maybe water vapour/humidity? There are other chemicals coming out of the tail pipe than just water and CO2 when alcohol is burned. Anytime you burn a fuel in the presence of nitrogen you can create some oxides of nitrogen. There are also other non regulated emissions, which may or may not be more harmful. Even clean burning fuels such as propane may not be so clean when not properly set up. When the automobile manufactures develop a vehicle, they spend millions of dollars on research ensuring that the emissions fall below the regulated targets. When a small company develops a retrofit kit for your gasoline vehicle to run on an alternative fuel do you really think it runs cleaner? What I am trying to say here is that you cannot expect to put an alternative fuel into a gasoline engine and get ultra low emissions. Just as with gasoline, the systems must be set up correctly to get a clean burn. Will McGonegal Electrical Engineer Mobile Sources Emissions Division Environment Canada wmcgonegal@xxx.ca ------------------------------ From: SRavet@xxx.com Date: Wed, 21 Aug 96 16:12:17 CDT Subject: re: Direct Ignition brewer@xxx.com (John Brewer) Wrote: | | I saw earlier today where Terry Hartman, in a post, made reference to the new | Corvette using eight coils and perhaps direct ignition. My nomenclature is | still coming up on the learning curve and I was wondering what direct | ignition is? I hope it is not an idea I have been kicking around in my | head for a few weeks now- then again if it is, I guess it means it was a | good idea even if I was beaten to the punch! | | John Brewer | | | "Any man who would trade liberty for security deserves neither." - Ben | Franklin | | | Direct ignition=no distributor. One small coil per plug, the ECM fires them directly instead of a larger coil that goes thru a distributor to get to the plug. It can also be set up as a wasted spark system, with one coil per 2 plugs. Both plugs fire when the coil is triggered, so care has to be taken to select cylinders such that one needs to be fired, the other is in the exhaust stroke. - --steve Steve Ravet sravet@xxx.com Baby you're a genius when it comes to cooking up some chili sauce... ------------------------------ From: Todd Knighton Date: Wed, 21 Aug 1996 16:59:14 +0000 Subject: Re: EFI musings Simply put: "Carbs DON'T" > Carbs don't flow as well as throttle bodies > Carbs (for my application) are worth $1500 as opposed to the $300 for > my EFI+Ignition > Carbs either don't flow enough at full flow, or are hopeless at idle. > Carbs aren't adjustable while driving. > Carbs don't provide a ignition, my EFI box does (thereby saving me > US$600 for a HPV-1 or similar). > Carbs don't provide a data logging system, my EFI box does. > Carbs suffer in High-G cornering or acceleration. you forgot heat soak and vapor lock. you forgot wet manifold problems and icing of the manifolds etc. etc. etc. Todd Knighton Protomotive Engineering P.S. If they could make the same power as EFI and worked more reliably, all the F1 and GTP cars would run them. ------------------------------ From: Todd Knighton Date: Wed, 21 Aug 1996 16:56:18 +0000 Subject: Re: Slide Throttles > Wouldn't engine vacuum also have a similar effect as well? Yeah, but the turbos have not only vacuum but boost as well and end up with a 6/1 pressure ratio over the thing on surge. engine vacuum is paltry enough, especially on big cammed motors that typically use slide to not affect it. > > Barrel throttles give very strange low flow characteristics, but do > > have very nice flow at wide open. They are hard to seal as well. The > > Yeah, but parts are available at the hardware store in the plumbing > department.... :-) Somehow I can't see using PVC on an engine. And someone previously yelled at me for mentioning "Radio Shack", huh! This one takes the cake! > Todd Knighton Protomotive Engineering ------------------------------ From: Todd Knighton Date: Wed, 21 Aug 1996 17:07:05 +0000 Subject: Re: Slide Throttles SRavet@xxx.com wrote: > OK, what is a slide throttle? I thought it was simply a "cover" that > slides over a "hole". But that wouldn't tend to stick closed. so what is > it? > It is just a plate over a hole, but try this. Put a ruler on the ground and move it around, easy right. now have someone stand on it, a little more difficult. Same idea, because of the great pressure differential caused by turbo motors and supercharged motors on surge, the plates have an enormous amount of pressure placed on them. They tend to deflect and stick in the tracks because the tracks are precision machined for a good seal and no rattle in the vertical direction. Apply a bit of curvature in a linear track, uhnt wallah, we have schticking. Todd Knighton Protomotive Engineering ------------------------------ From: jengel@xxx.NET Date: Wed, 21 Aug 1996 19:22:58 +600 Subject: Re: EFI musings EFI doesn't require the pressure drop across a venturi that a carb does. If it is set up for power (as apposed to emissions, cost or whatever) the reduced pressure drop (generally 1 - 3" Hg) gives better VE. Other that power, EFI is more adjustable i.e. mountains; the "warmup" time is shorter and the drivability is generally better (remember turning on the A/C in a car with a small engine? Nowadays it still moves like a slug, but the idle quality and drivability are better). Not to mention turbo applications. . . je > Date: Wed, 21 Aug 1996 12:06:43 -0400 > Don't get me wrong, I still lust for an EFI on my car, and I am still > waiting to hear back from the guy who installed the Edelbrock #3500. > But, in one page or less, what do you need and why not carbs? > > -- > Ed Hernandez > Ford Motor Company > ehernan3@xxx.com > ------------------------------ From: Matthew Lamari Date: Wed, 21 Aug 1996 20:11:48 -0500 Subject: Re: Re[2]: Zero Emissions Vehicle (was Electric Veh.) At 06:17 PM 8/21/96 EST, you wrote: > >>Someone with a heavily modified engine would merely use more alcohol, >>not add to any pollution problem (except maybe water vapour/humidity? > >There are other chemicals coming out of the tail pipe than just water >and CO2 when alcohol is burned. Anytime you burn a fuel in the >presence of nitrogen you can create some oxides of nitrogen. There >are also other non regulated emissions, which may or may not be more >harmful. > >Even clean burning fuels such as propane may not be so clean when not >properly set up. When the automobile manufactures develop a vehicle, >they spend millions of dollars on research ensuring that the emissions >fall below the regulated targets. When a small company develops a >retrofit kit for your gasoline vehicle to run on an alternative fuel >do you really think it runs cleaner? What I am trying to say here is >that you cannot expect to put an alternative fuel into a gasoline >engine and get ultra low emissions. Just as with gasoline, the >systems must be set up correctly to get a clean burn. > >Will McGonegal >Electrical Engineer >Mobile Sources Emissions Division >Environment Canada >wmcgonegal@xxx.ca > Won't argue with your credentials. . . . I didn't mean running alcohols in the very engines we have now. Just meant that something burning alcohol could retain the same style of engine (reciprocating piston, valves) to keep costs down, perhaps reusing standard parts from (previous?) model. I mean, that's what car companies do now, to keep costs down each subsequent year model is planned and they reuse so many parts, or at least get them from a common source with others (e.g. fuel pumps) as well as having different car models share parts. Customizing the computer for the fuel, as well as valvetrain, rings and compression, mightn't cost so much if an existing block, crank, transmission can be used in the first models. Cooler burning may allow cheaper solutions to other parts of the vehicle's design to compensate. I've seen from some curve graphs (for petroleum) that by changing the mix between extremes you go between nasty nitrogen emissions to nasty CO emissions. At stoich is a reasonable compromise of each. Perhaps with certain alcohols staying further away from the Nitrogen side mightn't be so as bad. I'm just guessing here, you'd probably have the hard data on this sort of thing in your division. Also, when considering alcohol, I'm more interested in it for renewability more than emissions. No matter how much oil's down there, I just hate the idea of the world running on and requiring something so finite. Producing it from sunlight via plant biochemical means just seems faster (faster than waiting 10000 years for the sun to brew us up some more fossil fuels.) I just think that, while getting a practical setup is difficult, it would be equally difficult to overcome the car company's reluctance to do expensive changes, and the incredible clout that the oil companies have in global affairs. Hey, that's business. Remember, even back in the very early 1900s, electric cars were in quite common use. Okay, they stunk; but so did the fuel cars. The industry just went the simplest path of using a readily available cheap fuel instead. Just imagine if all the work went into the electric car instead. Technologically, our electric and electronic knowledge utterly creams that of 90 years ago. Matthew. ------------------------------ From: "George M. Dailey" Date: Wed, 21 Aug 1996 21:09:57 -0500 Subject: Re: '97 Corvette engine, DIS At 07:58 AM 8/21/96 -0500, you wrote: ... >> The LS-1 is a completely new Chevrolet V8 engine with no parts >> interchanging with the old small block, or the LT5 for that matter. >> 3.9x3.6 bore/stroke, four bolt heads, evenly-spaced ports, gerotor oil >> pump driven off the front of the crank, thrust main now on center >> bearing, etc. >> > >There ARE some parts that interchange, although they are minor. The >hydraulic roller lifters and I believe rod bearings.... > >later, > >T. Does any one know enough about its internal workings (control module, EST principal, required sensors) to think it might be adapted to the previous generation of 5.7L SBCs. Without loseing all of your hair or sainity in th process. GMD ------------------------------ From: "George M. Dailey" Date: Wed, 21 Aug 1996 22:01:17 -0500 Subject: Re: EFI musings At 12:06 PM 8/21/96 -0400, you wrote: ..... Therefore, I still drive a 33 year >old, 2 ton, carbuereted, distributed, 2 valve, cast iron 2 speed >behemoth that is still woefully out of touch with today's technology. .... Surprise, surprise! I drive '58 truck. But I've cheated with the TPI & 700-R. I wonder what the other DIY'ers drive every day. Sound off. >So what? Here's the dangerous question: in light of the recent >discussion on analog vs digital EFI, and in the spirit of engineers >taking things to the extreme, why not stick to carburetors(ignore spark >control for a moment)? Simple, If you buy an already engineered system off of an junked car and retrofit to your carbed vehicle, you get that excellent mix if very low price & DIY satisfaction plus 14mpg city (plain HT-350 though). Imagine, carbed to TBI for about $200 total and a few weekends! You OEM guys did a fine job engineering those systems. >Yes, I am aware that this is an EFI list. But some very good points were >made about what EFI can do vs what the DIYer needs it to do, and what >sparked(pun intended) my question was a description of how both analog >and digital systems figure out how much fuel to provide, why they might >have to be trimmed/adjusted/calibrated, etc(even after you get it >working at one point in time), which eventually led to KISS and >analog/trimmming pots vs sophisti-digital, so I take it one step >further. Excellent logic my good man. Most DIY'ers wish to improve their vehicles as a bottom line. If you re-invent the wheel, you will probably kiss the K-I-S-S plan good by. >Don't get me wrong, I still lust for an EFI on my car, and I am still >waiting to hear back from the guy who installed the Edelbrock #3500. >But, in one page or less, what do you need and why not carbs? I wanted fuel economy beter than 8mpg city. Got it I wanted no loss of low & mid range torque. Got power improvements! I did not want to break the bank. From the other DIY EFI quotes, I've got the lowest price. I did not want weather to greatly impact engine performance. It does not. I wanted a system proven to last well over 100k miles without maintenance. Got it. I wanted no problem with vapor lock, as I idle for 1 hour in 120 deg summer heat with AC on full afterburner. None experienced. I wanted great under hood looks. No carb(s) look better than GM's TPEFI I wanted stock parts available at any parts house (not antique store). They got em. That, Ed Hernandez, is why a carb just would not cut the mustard _for _me_. Your vintage steel would be a prime candidate for an OEM conversion at a price and simplicity you would love. KISS KISS KiSS As you OEM guys say "...these thoughts are my own, and not necessarly those of my employer.", not that they care though. GMD ------------------------------ End of DIY_EFI Digest V1 #239 ***************************** 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".