DIY_EFI Digest Friday, December 10 1999 Volume 04 : Number 688 In this issue: virtual closed loop dwell regulation Re: DIY_EFI Digest V4 #687 /* Re Stoich */ Newbie needs sage advice Re: Newbie needs sage advice Re: DIY_EFI Digest V4 #687 /* Re Stoich */ 1228746 ECM Re: 1228746 ECM Re: Stoich See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Fri, 10 Dec 1999 05:45:37 PST From: "Robert Sandor" Subject: virtual closed loop dwell regulation I am working out an idea to fire sparks of a 4cyl. carburatted engine in right time without use of lookup tables or a knock detecton nor ionization current measurment.The only input to te regulator will be the RPM. The lookup table itself is not enaugh, because the temperature of the air and fuel varies. The knock detection and the ionisation current measurment are expensive methods. I hope a cheap method "virtual closed loop dwell regulation" will work. The main idea is to advance-retard dwell until maximal RPM is measured at fixed throttle position(Is this a fuzzy logic). I want to use separate coil for each cylinder. At very low RPM (like starting the engine) even multiple sparks could be applied. I also want to drive switching transistor without a MC3334 or alike IC. If the battery voltage and the inductivity of the coils are nearly constant, why to use an inteligent ignition driver IC? What do You think is this a good idea? Robert Sandor ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com ------------------------------ Date: Fri, 10 Dec 1999 21:46:43 +0800 From: "Ken Thompson" Subject: Re: DIY_EFI Digest V4 #687 /* Re Stoich */ From: Kevin Jaeger kjaeger@xxx.au We have binned every scrap of this weeks DIY_EFI. The subject that has been debated this week regarding STOICH is well known. Data out of your everyday hot rod type magazine, is not worth a whole lot in the total scheme of things. Who has herd of the practice of using the uni. library? Clare has. We could start a huge bomb fire with the tons of papers that have been written by people with more knowledge on this subject than most will acquire in a life time. Such a bomb fire would certainly unstoich the atmosphere a little more than it is today. Poor choice of words, I know. The Methane from the bullsh_t that I have read this week will most assuredly have the server administrators testing the air fuel ratio, by their servers. That has got to contaminate a few hard drives. I think I missed the meaning of some of Clare's verbals, but I think I heard the message loud and clear. I'm with you Clare. I believe I understand the direction Phil is coming from and the point he is attempting to make. I can think of perhaps another 50,000 related matters, that are yet to be mentioned by anyone. >From now on, how about narrowing down the topic range a little. If I were to pretend that this stuff were new to me and came in on the action early in the week, I would have learnt absolutely nothing by weeks end. This exclusive group is here for the purpose of learning the facts not wasting their time. Others have visited these areas a very long time before the majority of DIY readers had ever heard STOICH mentioned. "Come Let Us Reason Together" using data that is very readily available. Libraries, search engines and people like Clare and others should send in their references and mount arguments based on Science and Reason. People like Phil Irving were the technology maestros in their day, yet many of the assumptions (scientific knowledge of the day), turned out to be a pile of crap. Someone is bound to correct me, but I think that I'd be safe to state that Phil's engines won two F1 championships. The pile of crap I refer to was their understanding of the reasons behind certain phenomena related to cylinder fill while the piston was travelling towards the combustion chamber on the compression stroke. Now if this had been the topic, I would have come armed, but it isn't so I'm not. If the level of industry has not picked up by Monday, I can already tell that will be my favourite button, long before the mail is opened. Have a nice weekend, Kevin. > Date: Thu, 9 Dec 1999 22:02:07 -0500 > From: "Clare Snyder" > Subject: Re: Stoich > > This is a multi-part message in MIME format. > > - ------=_NextPart_000_003E_01BF4291.0905A800 > Content-Type: text/plain; > charset="iso-8859-1" > Content-Transfer-Encoding: quoted-printable > > believe what you want to believe - I asked > > > see: > http://www.chemical-stoichiometry.net/Resource_Titlepage.htm > http://www.chem.ualberta.ca/~plambeck/che/course/p0304x.htm > http://www.compusmart.ab.ca/plambeck/che/p101/p01172.htm > http://www.chem.ualberta.ca/~plambeck/che/p101/p01035.htm > http://www.compusmart.ab.ca/plambeck/che/p101/p01033.htm > http://www.chemical-stoichiometry.net/Tutorial_Titlepage.htm > http://www.chemical-stoichiometry.net/ > http://www.chemical-stoichiometry.net/tutorial.html > http://www.collingwood.org/chemistry/Curriculum%20Docs/ch1111.htm > http://www.chem.ualberta.ca/~plambeck/che/struct/s0201.htm > http://www.chemical-stoichiometry.net/begin_student.htm > http://www.compusmart.ab.ca/plambeck/che/course/vn41505x.htm > http://www.chem.ualberta.ca/~plambeck/che/p102/p0511x.htm > and > http://www.chem.ualberta.ca/courses/plambeck/p102/p02085.htm > > to start with. > Says if anybody is full of BS it's not me. Stoiciometry in many points = > of reference - other than combustion. > An excerpt from the last reference: > > Stoichiometric calculations involving redox reactions always begin with = > the balanced redox reaction. Once the balanced redox reaction has been = > obtained, the mole ratios will give the desired stoichiometric = > information. ............. > > Combustion is a Redox reaction (oxidation/reduction) > I've been told to make sure I've got my facts straight before posting = > "opinions" - the definition I gave may be a gross simplification - but = > the facts are the facts. > > Now, as for stoich being a moving target - A theoretically stoich = > mixture may not behave as stoich under certain conditions - something to = > do with elemental vs radical oxygen - elemental oxygen is not as = > reactive as radical oxygen, so if the O2 can be dissassociated into 2 X = > O, and the Hydrogen and Oxygen of the hydrocarbon fuel dissaciated into = > hydrogen and carbon, the reactions of oxygen + carbon =3D carbon = > dioxide, and hydrogen + oxygen=3Dwater can become stoichiometrically = > correct, Changing the reaction of nitrogen + oxygen=3Dnitous oxides (or = > oxides of nitogen - NOX) in the cyl can and does change the = > stoichiometry of the reaction in the cyl. This is, in effect, what EGR = > does to an engine. By inhibiting the formation of NOX the actual mixture = > ratio of gasoline and air required can be can be changed. Decrease NOX = > production and the mixture required for a stoichiometrically correct = > combustion of the fuel can be richened because more oxygen is available = > for the desired reaction. ------------------------------ Date: Fri, 10 Dec 1999 09:29:08 -0500 From: Rodney_L_Wiggins@xxx.com Subject: Newbie needs sage advice I am fairly new to the list so forgive my relative lack of knowledge. I need your help with a fundamental and somewhat philosophical question: Is it really worth replacing my stock FI system with a quality aftermarket system? The car is an 86 Porsche 944 turbo with early Bosch Motronic converted from vane to hot wire. The computer incorporates a manifold pressure sensor, which I assume references boost level and adjusts timing and fuel accordingly. (I don?t know the range of this sensor however, as I am running far more boost than the factory intended). The computer is crank triggered. In other words, it is my impression that I already have a lot of the features that make the aftermarket EFI systems desirable. So far I?ve just been using the white-lies method to get the stock computer to meet the added fuel requirement of the larger turbo, headwork, cam, nitrous, etc. Other than a minor drivability problem, this method has worked well. However, if there is horsepower to be gained, I am willing to move to the next level. Is there really a fundamental improvement to be had by moving to an aftermarket system? Of course, the downsides are clear, cost, complexity, potential tuning headaches. Does anyone out there regret taking this step? I love gadgets, love having complete control over all parameters, and I love knowing exactly how it all is working. So the EFI systems are very attractive to me. However, will I end up just spending lots of time and money to have a car that drives the same as it does now? I assume the engineers at Bosch and Porsche knew more than I do about EFI when the designed my system. Now that I?ve doubled the stock horsepower have I so completely surpassed their original design specs that I need to ditch what I have? I know the answer may contain a large ?opinion? component. This is fine, I?m hoping to learn from others? experience here. I suspect might have some trouble getting an unbiased answer to this question from an EFI sales rep. Thanks in advance, Rod Wiggins ------------------------------ Date: Fri, 10 Dec 1999 12:06:17 -0500 From: "Bruce Plecan" Subject: Re: Newbie needs sage advice None sage response: To really make a difference at the level your at is gonna take some money. The Felpro SEFI, Wide Band O2, ecm sounds about what you'd like/need. I have 0 personal experience with it, but have heard nothing but good about it. This is from 3-4 people at the gn list who are running it. Any time you run out of calibration room, your out of ecm, IMHO. Pasting/bandaiding things is a waste of $$, and effort. Grumpy | | I am fairly new to the list so forgive my relative lack of knowledge. I need | your help with a fundamental and somewhat philosophical question: Is it | really worth replacing my stock FI system with a quality aftermarket system? | The car is an 86 Porsche 944 turbo with early Bosch Motronic converted from vane | to hot wire. The computer incorporates a manifold pressure sensor, which I | assume references boost level and adjusts timing and fuel accordingly. (I don?t | know the range of this sensor however, as I am running far more boost than the | factory intended). The computer is crank triggered. In other words, it is my | impression that I already have a lot of the features that make the aftermarket | EFI systems desirable. So far I?ve just been using the white-lies method to get | the stock computer to meet the added fuel requirement of the larger turbo, | headwork, cam, nitrous, etc. Other than a minor drivability problem, this method | has worked well. However, if there is horsepower to be gained, I am willing to | move to the next level. Is there really a fundamental improvement to be had by | moving to an aftermarket system? Of course, the downsides are clear, cost, | ------------------------------ Date: Fri, 10 Dec 1999 12:13:04 -0500 From: "Bruce Plecan" Subject: Re: DIY_EFI Digest V4 #687 /* Re Stoich */ I'm finally being able to leave personalities aside, and just read for content, and this is all fascinating to me, often way over my head, but still interesting. Smart folks usually have just a tad more ego than others, and that tends to rear it's ugly head at times, and is a shame. I think in general if all 800 of us (DIY_EFI) hit a restaurant we'd all have coffee, and talk for 2-3 weeks. Just remember life has shades of gray, and even colors, not everything is black, and white. So much for my philosophy, today Grumpy | We have binned every scrap of this weeks DIY_EFI. The | subject that has been debated this week regarding STOICH | is well known. Data out of your everyday hot rod type | magazine, is not worth a whole lot in the total scheme of | things. Who has herd of the practice of using the uni. library? | Clare has. We could start a huge bomb fire with the tons of | papers that have been written by people | with more knowledge on this subject than most will acquire | in a life time. Such a bomb fire would certainly unstoich the | atmosphere a little more than it is today. Poor choice of words, | I know. | The Methane from the bullsh_t that I have read this week will | most assuredly have the server administrators testing the air | fuel ratio, by their servers. That has got to contaminate a few | hard drives. | I think I missed the meaning of some of Clare's verbals, but | I think I heard the message loud and clear. ------------------------------ Date: Fri, 10 Dec 1999 11:57:42 -0600 From: Don.F.Broadus@xxx.com Subject: 1228746 ECM Got a 1228746 ANLU at the yard last night. TBI , 1989 might be an old cop car would the app be 5.0 L or 5.7 L I didn't get the VIN number. Also got a 1227730 FML out of a 2.0 L Cavalier. Why did GM use a 730 on a 4 banger when a 6867 was used on other 2.0L cars ? Thanks Don ------------------------------ Date: Fri, 10 Dec 1999 13:10:19 -0500 From: "Bruce Plecan" Subject: Re: 1228746 ECM - ----- Original Message ----- From: To: Sent: Friday, December 10, 1999 12:57 PM Subject: 1228746 ECM 5.7L, auto LO5 Who knows the infinite wisdom, at Corporate HQ. Grumpy | Got a 1228746 ANLU at the yard last night. TBI , 1989 might be an old cop | car | would the app be 5.0 L or 5.7 L I didn't get the VIN number. | Also got a 1227730 FML out of a 2.0 L Cavalier. Why did GM use a 730 on | a 4 banger when a 6867 was used on other 2.0L cars ? | Thanks Don | ------------------------------ Date: Fri, 10 Dec 1999 10:18:26 -0800 (PST) From: Orin Eman Subject: Re: Stoich [admin] Please turn the html off on posts to the list. It makes a real mess of the digests. Orin. ------------------------------ End of DIY_EFI Digest V4 #688 ***************************** 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".