DIY_EFI Digest Wednesday, April 28 1999 Volume 04 : Number 247 In this issue: Re: Fuel injection plugs Direct Injection Surplus Sale on GM Harnesses Can anymone ID fuel injector source Re: Direct Injection Re: Direct Injection Re: Direct Injection Re: Surplus Sale on GM Harnesses Can anymone ID Re: Direct Injection Re: Direct Injection Re: Direct Injection Re: Fuel injection plugs Re: Direct Injection Toyota management mod limitations?? multiple O2 sensors Re: Fuel injection plugs Re: Fuel injection plugs Re: Fuel injection plugs Re: Toyota management mod limitations?? Re: Weber Marelli WD48.08 info... See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Wed, 28 Apr 1999 06:32:35 -0400 From: James Ballenger Subject: Re: Fuel injection plugs Howard Wilkinson wrote: > James: > Really they don't operate at a 70x mixture...... the real purpose > of direct injection on 4 cycle engines is to achieve true charge > stratification so that the total mixture ratio may well be 70x, but > the mixture which is near the plug is at the proper 14x ratio. So the compressed air/fuel ratio pumped into the cylinder is 14.7, but the volume injected can give a 70:1? I am still learning, could you please define "True charge stratification?" > Direct injection actually results in poorer atomizaton, and direct > injection > engines (4 cycle) use dual mode operation with port injection at > higher power settings, and direct injection at low power settings. Orbital claims better atomization than mpi, a mean diameter of less than 8 microns. High power meaning high pressure? > The obvious advantage of the extreme lean total mixtures at lower > power settings is that it allows a full charge or nearly full charge > of air which means higher effective compression ratio, and more > material in the cylinder to create pressure from the combustion > process. It would also mean very good fuel economy and better hc and co emissions too right? Also because of the quick burn of the mixture lower NOx? > Direct injection tends to be detrimental to max power output. They did a test with a ford zetec "modified" engine comparing mpi versus their system. At full load and 12.5:1 they had better torque figures and VE across the range. > Orbital if I'm not mistaken is working primarily with 2 cycle engines, > the idea being that no fuel is blown out the port which increases the > efficiency to about the typical .5 lb / hp/hr of a 4 cycle. The > Mercury Optimax has demonstrated this to work very well. They seem to be better entrenched in the 2 cycle market, but most of their recent efforts seem to be with 4 cycle engines. > Direct injection is the first real significant improvement in gas > engines since very nearly the beginning. Other "improvements" such as > overhead valves, and overhead cam, superchargers, turbos, EFI, etc... > really didn't offer much other than slightly greater power to weight > ratio. Overhead valve engines for example of the same compression > ratios didn't offer much greater efficiency or dependability, Overhead > cam only reduced the parts count slightly and allowed higher RPM, > boosted induction offered no benefit except a slightly better power to > weight ratio, EFI offers a slightly improved fuel management.... In > real life I don't see much improvement between a properly set up carb > and an EFI system on comparable vehicles owned by people I know. The > main advantage of EFI is emissions control and a system where the user > can't easily tinker with it. I'd have to agree with you, except for the turbo. As evidence by buick gn's, a significant can be seen imo. > Direct injection on the other hand offers an increase in > efficiency in vehicles of as much as 30% if the numbers floating about > are to be believed. > I'd love to have something like this to play with someday.... > H.W. Me too, I just wish I could play with it now ;-) btw, my source for all the orbital mumbo jumbo was http://www.orbeng.com.au/pdf/sae98.pdf James Ballenger ------------------------------ Date: Wed, 28 Apr 1999 10:55:48 GMT From: bob@xxx.com (Robert Harris) Subject: Direct Injection Detrimental to power output - tell that to the Spitfire pilots that ate it big time when they met the Direct Fuel Injected Me109's etc. Tell that to the drivers of other makes who ran up against Mercedes Direct Injected 300's in the early fifties. Bosch and Mercedes routinely used Direct Injection thru the mid fifties. Tis an old old idea laddies - and was making POWER long before Orbital was a stain on daddies leg. Try like operational on German aircraft engines in 1934. Some day, when you have nothing to do, you might enlighten yourself about mixtures. Like try inverting fuel air mixtures i.e. holding fuel constant and changing air and plotting air to fuel vs power. You will find that the power varies far more with the amount of fuel than with the amount of air. Then you will realize that max power is made with the fuel held equal in all cylinders - - the first major benefit. Then - re-read about the Bosch System - which Horror of Horrors was a direct adaption of Bosch Diesel systems and shared most parts. Since they injected the fuel after the intake valve was closed - well into the compression stroke and these old krauts knew all about "atomization" and vaporization etc ad nauseum, they did not screw around with puffs of air or whatever - but passed go, collected their 200 dollars and went to aiming the fuel spray right onto the face of the exhaust valve - instantaneous fuel evaporation in a CLOSED cylinder and heavens to murgitoid, actually cooling the exhaust valve. Silly stupid german engineers didn't read the DIY_EFI archives on how to get optimum fuel atomization or care about it. They got instant vaporization - screw atomization, they cooled the exhaust valve so they could get even higher power outputs and by cooling the HOTTEST spot in the cylinder, they were able to raise the compression ratio at least 2 whole ratios on the same octane fuel. With total vaporization, they were able to get incredible throttle response, power and performance. But silly us didn't realize that all they wanted to do was stratify the charge, get milage by sacrificing performance, and have poorer mixture's than port injection. Great Nazi propaganda apparatus must have covered this up along with those stupid engineers at Bosch who forget to put the port injector on the Messerschmits and Mercedes for high power usage. Further for the record, Bosch developed the timed port fuel injection as a CHEAP almost as good replacement for the Direct Mechanical Injection and then went on to develop the K "CIS" system as a more efficient implementation of Fuel injection than the timed port injection and was only forced backwards because of air pollution constraints - not power not economy - just smog nazies. If you want Direct Injection without waiting for someone to get around to re-inventing the wheel, you can directly adapt an automotive/light truck diesel unit by running a little 100 to 1 synthetic 2 cycle oil with your gasoline. Of course, then you would have to come over to the dark side and use air control instead of fuel control because the high pressure ~1800 PSI side doesn't let you do much. But then why bother - we all know that fuel shot thru a diffuser nozzle at 1800 psi is not going to be well atomized without a puff of air or be as good as piss dribbles into the intake runner timed to whizz into the cylinder when the valve is open. 1963 Ford C-600 Prison Bus Conversion "Home" 1971 Lincoln Continental 460 "Christine" 1972 "Whale" Mustang awaiting transplant 1978 Dodge Long Bed Peeek Up "Bundymobile" Habaneros - not just for breakfast anymore ------------------------------ Date: Wed, 28 Apr 1999 09:01:14 -0400 (EDT) From: root Subject: Surplus Sale on GM Harnesses Can anymone ID If anyone is interested Mendelson & Co. is selling surplus GM harnesses. If anyone can id them the GM numbers are 12069591 12069696 28129040. They're asking $5 each Might be worth the $15 just to see what they are. Probably a useless door or trunk harness but what if its a 747 engine bay or dash harness ? look at http://www.meci.com Their part numbers are 130-0031 130-0032 130-0081 ------------------------------ Date: Wed, 28 Apr 1999 07:32:54 -0700 From: "John T. Luyster" Subject: fuel injector source Hi, I am new to this internet thing and am trying to find a larger injector for a project vehicle I'm working on. I am supercharging a CLK 430 Mercedes and need a 28lbs/hr injector. Bosch R&D in Farmington , IL wasn't too helpful. After doing some research I believe I need this Bosch part number. 0 280 155 839 or 840. This injector is the new EV6 design about the diameter of a marking pen. Really small. If you don't know could you point me in a direction to find them. Thanks John Luyster ------------------------------ Date: Wed, 28 Apr 1999 10:23:35 -0400 (EDT) From: "Clive Apps Techno-Logicals 416 510 0020" Subject: Re: Direct Injection > > Detrimental to power output - tell that to the Spitfire pilots that ate it big > time when they met the Direct Fuel Injected Me109's etc. Tell that to the > drivers of other makes who ran up against Mercedes Direct Injected 300's in > the early fifties. Bosch and Mercedes routinely used Direct Injection thru > the mid fifties. Tis an old old idea laddies - and was making POWER long > before Orbital was a stain on daddies leg. Try like operational on German > aircraft engines in 1934. Robert, this couln't have possibly worked it wasn't simulated on a computer before it was built and it had no electronic controls it's just not possible to make a FI system effeicient without hanging a few hundred pounds of miscellaneous wiring and computer chips off it BTW very nice flame Clive ------------------------------ Date: Wed, 28 Apr 1999 09:02:10 -0700 From: "Steve" Subject: Re: Direct Injection >Then - re-read about the Bosch System - which Horror of Horrors was a direct >adaption of Bosch Diesel systems and shared most parts. Since they injected >the fuel after the intake valve was closed - well into the compression stroke >and these old krauts knew all about "atomization" and vaporization etc ad >nauseum, they did not screw around with puffs of air or whatever - but passed >go, collected their 200 dollars and went to aiming the fuel spray right onto >the face of the exhaust valve - instantaneous fuel evaporation in a CLOSED >cylinder and heavens to murgitoid, actually cooling the exhaust valve. > I don't know about the aero engines, but according to Karl Ludvigsen's book Mercedes-Benz Quicksilver Century, the 300SL's in the '50's used the following setup: "The final siting of the injection nozzles was able to take advantage of the provisions made for the two different spark plug positions tried in the 300SL engine. The spark plug remained in the cylinder head while the former plug positions in the block, the ones used by the original 300 six, were taken up (although in modified form) by the injection nozzles. There they sprayed from the hot side to the cool side of the chamber, across the face of the valves, during the intake stroke." And later he details information on the straight eight engine's injection. "Selected was a point on the cylinder wall just below the inlet valve, with the centerline of the nozzle angled upwards at 12.5 degrees. It's spray emerged in a 30 degree cone at a pressure of 1200 psi. Flow began 30 degrees after top dead center on the inlet stroke and continued for 160 degrees." Regards, Steve ------------------------------ Date: Wed, 28 Apr 1999 09:26:15 -0400 From: "Gary Derian" Subject: Re: Direct Injection I am aware of Orbital's work. Their system is a great way to make a 2 stroke meet emission requirements. The air assisted injection is necessary to achieve fuel air mixing in a limited time since injection occurs after the exhaust port is closed. Bosch direct injection used a mechanical pump timed to END the injection cycle at 60 deg ATDC on the intake stroke. This gives time for mixing. To inject after the intake valve closes greatly reduces the mixing time and may result in unwanted stratification. Wanted stratification is another matter. The main benefits to direct injection explained here seem to center on the ability to create a stratified charge, a combustible mixture near the spark with excess air elsewhere. This improves part throttle economy. It also reduces HC and CO emissions. NOx are also reduced but not enough to suit current emissions standards. For that, reducing catalysts are needed but they will not reduce NOx in the presence of excess oxygen. With a stochiometric mix, stratified charge becomes moot. I recognize that it is possible to have with a lean mixture in certain operating regimes and still meet NOx. Honda and GM did this but I believe these were considered emission defeat devices and are no longer used. For economy, modern cars have 5 and 6 speed transmissions with very tall cruise gears. These techniques reduce pumping loses without the complex engine controls. So now we have stochiometric fuel mix and economy gearing. So where does direct injection help? I'm not saying we should stop research on this matter, but this list, it seems to me, is primarily concerned with improving the performance of our cars by modifying the factory injection systems. For these purposes, direct injection has no benefit. Gary Derian ------------------------------ Date: Wed, 28 Apr 1999 13:46:45 -0400 From: "Bruce Plecan" Subject: Re: Surplus Sale on GM Harnesses Can anymone ID They are useless. This came up a couple weeks ago, and I got several of each to do the 25 min order. They are lighting bits. Grumpy - ----- Original Message ----- From: root To: Sent: Wednesday, April 28, 1999 9:01 AM Subject: Surplus Sale on GM Harnesses Can anymone ID > If anyone is interested Mendelson & Co. is selling surplus GM harnesses. > If anyone can id them the GM numbers are 12069591 12069696 28129040. > They're asking $5 each > > Might be worth the $15 just to see what they are. > Probably a useless door or trunk harness but what if its a 747 engine > bay or dash harness ? look at http://www.meci.com > Their part numbers are 130-0031 130-0032 130-0081 > > ------------------------------ Date: Wed, 28 Apr 1999 11:08:02 -0700 From: Aaron Willis Subject: Re: Direct Injection At 09:26 AM 4/28/99 -0400, you wrote: >So now we have stochiometric fuel mix and economy gearing. So where does >direct injection help? I'm not saying we should stop research on this >matter, but this list, it seems to me, is primarily concerned with improving >the performance of our cars by modifying the factory injection systems. For >these purposes, direct injection has no benefit. > >Gary Derian > > > Bearing in mind that I am an engineering STUDENT and not an engineer proper, that I am not yet experienced in EFI or alternatives to it, and (flame suit on) that I am a proponent of the classic/ridiculously outdated Skinner's Union carburetter ( :-)sic), may I humbly offer my two cents to the group? I find the DIY portion of the title more important than the EFI, and greatly enjoy hearing about not only DIY-OEM-EFI theory, but aftermarket EFI, CIS, direct injection, alternative fuels, additional fuels, supercharging, turbocharging, exhaust header design, port, chamber, and cam design, obsolete engines, oddball engines, alternative engines, twin engines, etc etc ad nauseum. There seems to be a vast collection of knowledge and experience on this list, and it is always entertaining and informative to see where the posts go. Yes, they do get fairly far off-topic, but they have so much good information it seems like a far greater benifit than detriment. I know this was unsolicited, but hopefully somebody out there can direct me to another list that has a broader focus if I am missing the point. And yes, Robert, that was a very nice flame. Well done. Aaron Willis ICQ #27386985 AOL IM: hemiyota http://surf.to/garage-te51 Garage TE51 International ------------------------------ Date: Wed, 28 Apr 1999 16:06:50 -0400 (EDT) From: William T Wilson Subject: Re: Direct Injection On Wed, 28 Apr 1999, Clive Apps Techno-Logicals 416 510 0020 wrote: > this couln't have possibly worked > it wasn't simulated on a computer before it was built Wonder how they built the first computer then? ;) > it's just not possible to make a FI system effeicient without hanging > a few hundred pounds of miscellaneous wiring and computer chips off it Unless you are being facetious, I point you to... every diesel engine made before the advent of electronic controls? ------------------------------ Date: Wed, 28 Apr 1999 16:36:08 -0400 From: "Bruce Plecan" Subject: Re: Direct Injection - ----- Original Message ----- From: William T Wilson To: Subject: Re: Direct Injection Was captured from the Aleins in Roswell, Sneezy > > this couln't have possibly worked > > it wasn't simulated on a computer before it was built > Wonder how they built the first computer then? ;) ------------------------------ Date: Fri, 30 Apr 1999 12:19:12 -0700 From: "Howard Wilkinson" Subject: Re: Fuel injection plugs James: I didn't say that very well..... What I meant to say was that due to fuel charge stratification the area in which the spark plug is located where combustion is initiated is at normal ratio, but the surrounding area may be extremely lean. The ideal engine (in terms of efficiency) is like a diesel where power output is controlled by fuel supplied not by air fuel mixture being supplied under a vacuum (throttling) which results in lower max pressure prior combustion. Basic thermodynamic theory shows that for a given amount of thermal energy the pressures will be higher if a full charge of air is available for expansion. We are after all developing power from the pressure, so any way we can achieve more pressure from a given amount of fuel will improve our efficiency. My comments on 4 cycle direct injection were not relating to the Orbital system. It's been awhile since I chased this info down on the web. I believe Mitsubishi or some other Japanese company is at the forefront of direct injection 4 cycle engines and may actually have a car on the market by now. This type of system was the one I described with the two injectors, one being direct, and one port. I believe they are using the same basic Siemens type injector as is used by Orbital, and info on these developments is probably to be found from the Siemens web site. Try the link below... I'm not sure if it's current. http://www.frostbyte.com/siemens/siemens/powertrain/ H.W. Date: Wednesday, April 28, 1999 5:34 AM Subject: Re: Fuel injection plugs >Howard Wilkinson wrote: > >> James: >> Really they don't operate at a 70x mixture...... the real purpose >> of direct injection on 4 cycle engines is to achieve true charge >> stratification so that the total mixture ratio may well be 70x, but >> the mixture which is near the plug is at the proper 14x ratio. > >So the compressed air/fuel ratio pumped into the cylinder is 14.7, but the > >volume injected can give a 70:1? I am still learning, could you please >define "True charge stratification?" > >> Direct injection actually results in poorer atomizaton, and direct >> injection >> engines (4 cycle) use dual mode operation with port injection at >> higher power settings, and direct injection at low power settings. > >Orbital claims better atomization than mpi, a mean diameter of less than 8 > >microns. High power meaning high pressure? > >> The obvious advantage of the extreme lean total mixtures at lower >> power settings is that it allows a full charge or nearly full charge >> of air which means higher effective compression ratio, and more >> material in the cylinder to create pressure from the combustion >> process. > >It would also mean very good fuel economy and better hc and co emissions >too right? Also because of the quick burn of the mixture lower NOx? > > >> Direct injection tends to be detrimental to max power output. > > They did a test with a ford zetec "modified" engine comparing mpi >versus their system. At full load and 12.5:1 they had better torque >figures and VE across the range. > >> Orbital if I'm not mistaken is working primarily with 2 cycle engines, >> the idea being that no fuel is blown out the port which increases the >> efficiency to about the typical .5 lb / hp/hr of a 4 cycle. The >> Mercury Optimax has demonstrated this to work very well. > > They seem to be better entrenched in the 2 cycle market, but most of >their recent efforts seem to be with 4 cycle engines. > >> Direct injection is the first real significant improvement in gas >> engines since very nearly the beginning. Other "improvements" such as >> overhead valves, and overhead cam, superchargers, turbos, EFI, etc... >> really didn't offer much other than slightly greater power to weight >> ratio. Overhead valve engines for example of the same compression >> ratios didn't offer much greater efficiency or dependability, Overhead >> cam only reduced the parts count slightly and allowed higher RPM, >> boosted induction offered no benefit except a slightly better power to >> weight ratio, EFI offers a slightly improved fuel management.... In >> real life I don't see much improvement between a properly set up carb >> and an EFI system on comparable vehicles owned by people I know. The >> main advantage of EFI is emissions control and a system where the user >> can't easily tinker with it. > > I'd have to agree with you, except for the turbo. As evidence by >buick gn's, a significant can be seen imo. > >> Direct injection on the other hand offers an increase in >> efficiency in vehicles of as much as 30% if the numbers floating about >> are to be believed. >> I'd love to have something like this to play with someday.... >> H.W. > >Me too, I just wish I could play with it now ;-) > >btw, my source for all the orbital mumbo jumbo was >http://www.orbeng.com.au/pdf/sae98.pdf > >James Ballenger > > ------------------------------ Date: Fri, 30 Apr 1999 13:22:50 -0700 From: "Howard Wilkinson" Subject: Re: Direct Injection Robert: I suspect that we are comparing apples to oranges here. The engines you are speaking of are extreme high performance supercharged engines, and I suspect that direct injection was a strategy to help combat detonation / as was the water injection system common on WW2 aircraft. The problem with direct injection which resulted in the use of two injectors (not the Orbital system) was atomization was not as good as with port injection resulting in less max power output. I might add that as these systems of which you speak are mechanical systems it is very likely that very high pressures are used which results if far better atomization..... a well known principle. Nice flame!!..... however we are talking about a whole different set of problems here. In automotive applications a typical engine is only operating at a small percentage of it's full output, and these systems are designed with the intent of getting max efficiency in this range. You can't directly compare an engine designed with this in mind to one designed to race...... it's a different world. If you wish to live in the past, or compare race cars with road cars that's your problem.... None of the engines you speak of even approaches the type of volumetric efficiency achieved by these modern engines at the same percentages of max power output. Efficiencies of as high as .3 lb per BHP/hr are frequently quoted (I'm not saying I believe it). You're welcome to play with your Spitfires and Mercedes race cars.... I for one can't even come close to affording such toys. Furthermore this comment is utter nonsense: >If you want Direct Injection without waiting for someone to get around to >re-inventing the wheel, you can directly adapt an automotive/light truck >diesel unit by running a little 100 to 1 synthetic 2 cycle oil with your >gasoline. No doubt you could operate a diesel fuel injection system on a 100x1 oil mix, but how do you propose to regulate mixture?? This I'm sure could be done in some way.... do you propose to connect a servo of some sort to the fuel control to the injector pump so that as the throttle is opened or closed the correct amount of fuel is supplied? These systems fire each injector every other revolution, and the throttle only supplies more or less fuel to a diesel to regulate power........ this doesn't work on a gas engine as the mixture variation prevents ignition if too lean or too rich. To imply that this is a fairly simple project is to greatly oversimplify things. It is neither simple or practical. I work with these systems every day and am very familiar with them....... don't try to feed me this load of nonsense. H.W. - -----Original Message----- From: Robert Harris To: diy_efi@xxx.edu Date: Wednesday, April 28, 1999 6:47 AM Subject: Direct Injection >Detrimental to power output - tell that to the Spitfire pilots that ate it big >time when they met the Direct Fuel Injected Me109's etc. Tell that to the >drivers of other makes who ran up against Mercedes Direct Injected 300's in >the early fifties. Bosch and Mercedes routinely used Direct Injection thru >the mid fifties. Tis an old old idea laddies - and was making POWER long >before Orbital was a stain on daddies leg. Try like operational on German >aircraft engines in 1934. > >Some day, when you have nothing to do, you might enlighten yourself about >mixtures. Like try inverting fuel air mixtures i.e. holding fuel constant and >changing air and plotting air to fuel vs power. You will find that the power >varies far more with the amount of fuel than with the amount of air. Then you >will realize that max power is made with the fuel held equal in all cylinders >- the first major benefit. > >Then - re-read about the Bosch System - which Horror of Horrors was a direct >adaption of Bosch Diesel systems and shared most parts. Since they injected >the fuel after the intake valve was closed - well into the compression stroke >and these old krauts knew all about "atomization" and vaporization etc ad >nauseum, they did not screw around with puffs of air or whatever - but passed >go, collected their 200 dollars and went to aiming the fuel spray right onto >the face of the exhaust valve - instantaneous fuel evaporation in a CLOSED >cylinder and heavens to murgitoid, actually cooling the exhaust valve. > >Silly stupid german engineers didn't read the DIY_EFI archives on how to get >optimum fuel atomization or care about it. They got instant vaporization - >screw atomization, they cooled the exhaust valve so they could get even higher >power outputs and by cooling the HOTTEST spot in the cylinder, they were able >to raise the compression ratio at least 2 whole ratios on the same octane >fuel. With total vaporization, they were able to get incredible throttle >response, power and performance. > >But silly us didn't realize that all they wanted to do was stratify the >charge, get milage by sacrificing performance, and have poorer mixture's than >port injection. Great Nazi propaganda apparatus must have covered this up >along with those stupid engineers at Bosch who forget to put the port injector >on the Messerschmits and Mercedes for high power usage. > >Further for the record, Bosch developed the timed port fuel injection as a >CHEAP almost as good replacement for the Direct Mechanical Injection and then >went on to develop the K "CIS" system as a more efficient implementation of >Fuel injection than the timed port injection and was only forced backwards >because of air pollution constraints - not power not economy - just smog >nazies. > >If you want Direct Injection without waiting for someone to get around to >re-inventing the wheel, you can directly adapt an automotive/light truck >diesel unit by running a little 100 to 1 synthetic 2 cycle oil with your >gasoline. > >Of course, then you would have to come over to the dark side and use air >control instead of fuel control because the high pressure ~1800 PSI side >doesn't let you do much. But then why bother - we all know that fuel shot >thru a diffuser nozzle at 1800 psi is not going to be well atomized without a >puff of air or be as good as piss dribbles into the intake runner timed to >whizz into the cylinder when the valve is open. > >1963 Ford C-600 Prison Bus Conversion "Home" >1971 Lincoln Continental 460 "Christine" >1972 "Whale" Mustang awaiting transplant >1978 Dodge Long Bed Peeek Up "Bundymobile" > >Habaneros - not just for breakfast anymore > ------------------------------ Date: Wed, 28 Apr 1999 22:53:15 +0100 From: "Chris Wilson" Subject: Toyota management mod limitations?? I have a 94 Japanese spec (imported to UK) Supra twin turbo,but my question also applies to MR2 turbos.Bear in mind,in the case of the Jap spec Supras,and the later MR2's,that air flow signals are speed density,and not,like all US Supras,air flap metered. OK,what I want to do is get away from analogue add on cludges,that go by bizzare names from Greddy and the like.I want to re map the ignition and the fuel sides to accomodate raised boost,and I want to remove the safety mechanism of a fuel cut. Am I right in thinking Toyota don't use a removable eprom on the ECU,but it is mapped in another way? Does this mean that,realistcally,I need to bin the Toyo system,and go for something like Motec,and start afresh? Does anyone do any system that adds on to the Toyo ECU,to allow re mapping? Thanks.I am beginning to regret buying this thing,it appears I haven't done my homework,and it is limited in how much control I have over mapping,compared to say,Subaru or Nissan,which use a changeable and updateable eprom Thanks. ------------------------------ Date: Wed, 28 Apr 1999 18:12:57 -0500 From: Don.F.Broadus@xxx.com Subject: multiple O2 sensors Take a look at the JUNE 1999 issue of Chevy High Performance magazine. On page 83 is a photo of John Lingenfelter's 357 cube race truck engine. There are O2 sensors in each header tube. Only the passenger side is shown but it is likely the driver side header has 4 sensors also. Two Holley 750 dominators feed the engine. Pi Research on board data acquisition collects all of the sensor data. The article does not reference the O2 sensors and they appear to be at least 3 wire types. Has any one seen this set up before ? Don ------------------------------ Date: Wed, 28 Apr 1999 19:14:50 -0700 From: "Walter Sherwin" Subject: Re: Fuel injection plugs >This is what I have in mind. Liquid propane injection with a dual >injector/spark device. > >Charlie Springer Is there a commercially available "dual injector/spark device", such as you describe, that one could purchase over-the-counter? Where would a person look/call/read to find out more about it? Walt. ------------------------------ Date: Wed, 28 Apr 1999 18:35:10 -0600 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: Fuel injection plugs Hi Howard-- Had to finally jump in here-- > I didn't say that very well..... What I meant to say was that due >to fuel charge stratification the area in which the spark plug is >located where combustion is initiated is at normal ratio, but the >surrounding area may be extremely lean. ' This is correct, and now well said. The lean overall mixture in these engines at part throttle allows better economy by reducing PUMPING losses significantly. Basically--throttling is an irreversible process, and all the air that passes through the engine when it is throttled must be pumped from manifold pressure back up to atmospheric pressure in order to get out of the exhaust pipe. > The ideal engine (in terms of efficiency) is like a diesel An Otto cycle is actually MUCH more efficient at full throttle than a diesel, especially if you only consider the "air efficiency"--adding fuel to the mix brings it closer to a diesel, but not down that faR! where >power output is controlled by fuel supplied not by air fuel mixture >being supplied under a vacuum (throttling) which results in lower max >pressure prior combustion. Basic thermodynamic theory shows that for >a given amount of thermal energy the pressures will be higher if a >full charge of air is available for expansion. This is incorrect. Thermal efficiency depends upon the PEAK TEMPERATURE reached during th cycle and upon the effective EXPANSION RATIO which is available during the power stroke of the cycle. For a given compression ratio, you will always get the highest possible peak temperature for the cycle at a stoichiometric a/f ratio. Diesels cannot run at stoich--the fuel can never find all the air!! There are some things which modify this to a degree, such as selective burning of hydrogen (with a higher heat of combustion) rather than carbon at slightly rich a/f ratios, and more complete combustion of the fuel at slightly lean a/f ratios--but these factoids are not that relevant to this discussion. We are after all >developing power from the pressure, What you are really developing power from is the MEAN EFFECTIVE PRESSURE during the cycle. A higher peak means nothing (except higher stress on the engine) if the mean pressure is lower! so any way we can achieve more >pressure from a given amount of fuel will improve our efficiency. As stated above, it is temperature that matters most! Where a diesel gains is in two places: At part throttle--they have no pumping losses. At any throttle--they generally have a higher expansion ratio. Where spark engines gain-- Lower internal friction (the cross-over point where efficiency gains from higher compression/expansion ratio are actually CANCELLED OUT by increases in internal friction happens somewhere in the 11.5 to 13.5 :1 compression ratio range. ) A much more efficient thermodynamic cycle. The ability to use virtually all of the air they breathe in for combustion. The ability to burn their fuel efficiently at much higher engine speeds. Regards, Greg ------------------------------ Date: Wed, 28 Apr 1999 20:43:55 -0400 From: James Ballenger Subject: Re: Fuel injection plugs Howard Wilkinson wrote: > James: > I didn't say that very well..... What I meant to say was that due > to fuel charge stratification the area in which the spark plug is > located where combustion is initiated is at normal ratio, but the > surrounding area may be extremely lean. That makes more sense, thanks for clearing it up. > The ideal engine (in terms of efficiency) is like a diesel where > power output is controlled by fuel supplied not by air fuel mixture > being supplied under a vacuum (throttling) which results in lower max > pressure prior combustion. Basic thermodynamic theory shows that for > a given amount of thermal energy the pressures will be higher if a > full charge of air is available for expansion. We are after all > developing power from the pressure, so any way we can achieve more > pressure from a given amount of fuel will improve our efficiency. Doesn't greater effeciency tend to indicate, at least, a potential for greater max power output? All else being equal, if the system was setup for performance it would do so more easily than an mpi system? > My comments on 4 cycle direct injection were not relating to the > Orbital system. It's been awhile since I chased this info down on the > web. I believe Mitsubishi or some other Japanese company is at the > forefront of direct injection 4 cycle engines and may actually have a > car on the market by now. This type of system was the one I described > with the two injectors, one being direct, and one port. I believe > they are using the same basic Siemens type injector as is used by > Orbital, and info on these developments is probably to be found from > the Siemens web site. Try the link below... I'm not sure if it's > current. > http://www.frostbyte.com/siemens/siemens/powertrain/ It's a dead link. I have seen a few direct injection designs in car mags from chrysler, probably in cooperation with mitsubishi, that are interesting. James Ballenger ------------------------------ Date: Fri, 30 Apr 1999 08:38:51 +0800 From: "WILMAN" Subject: Re: Toyota management mod limitations?? - ---------- > From: Chris Wilson > To: DIY_EFI List > Subject: Toyota management mod limitations?? > Date: Thursday, April 29, 1999 5:53 AM > > I have a 94 Japanese spec (imported to UK) Supra twin turbo,but my question > also applies to MR2 turbos.Bear in mind,in the case of the Jap spec > Supras,and the later MR2's,that air flow signals are speed density,and > not,like all US Supras,air flap metered. > > OK,what I want to do is get away from analogue add on cludges,that go by > bizzare names from Greddy and the like.I want to re map the ignition and the > fuel sides to accomodate raised boost,and I want to remove the safety > mechanism of a fuel cut. > > Am I right in thinking Toyota don't use a removable eprom on the ECU,but it > is mapped in another way? Does this mean that,realistcally,I need to bin the > Toyo system,and go for something like Motec,and start afresh? Does anyone do > any system that adds on to the Toyo ECU,to allow re mapping? > > Thanks.I am beginning to regret buying this thing,it appears I haven't done > my homework,and it is limited in how much control I have over > mapping,compared to say,Subaru or Nissan,which use a changeable and > updateable eprom > > Thanks. > > Try gems@xxx. They do an " Implant" for Toyota ECU's which then allow them to be programmable. ------------------------------ Date: Fri, 30 Apr 1999 08:33:18 +0800 From: "WILMAN" Subject: Re: Weber Marelli WD48.08 info... - ---------- > From: Daniel R. Henriksson > To: diy_efi@xxx.edu > Subject: Weber Marelli WD48.08 info... > Date: Wednesday, April 28, 1999 4:40 PM > > Hi > Is there anyone out there who has any in-depth info on the internals of the Weber Marelli WD48.08 injection system? > It's fitted in the -92 Ford Sierra Cosworth's. > > It's a Motorola 6808 based box. > > I'm looking for calibration table configs and parameter specs. > > I'm also interested in bin files from such boxes, i have the stock bin file if anyone is interested. > > Any info of any kind would be welcomed! > > BR > Daniel Henriksson I have a tuned file from a British tuner for a Ford Escort Cosworth. Could you e-mail me your stock file? Wilman > > ------------------------------ End of DIY_EFI Digest V4 #247 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. 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