DIY_EFI Digest Thursday, 28 August 1997 Volume 02 : Number 294 In this issue: Re: Microcontrollers used in OEM systems non-EFI crap Re: is their Re: Microcontrollers used in OEM systems RE: Backpressure and torque RE: Back pressure and torque Re: Microcontrollers used in OEM systems Re: Microcontrollers used in OEM systems LED bar graph Re: Backpressure and torque Re: Back pressure and torque Off topic, real brief Re: Backpressure and torque Re: CDI, accelerometer RE: Back pressure and torque interesting kits -- automotive app Tuning Book List RE: interesting kits -- automotive app Re: Back pressure and torque Re: Back pressure and torque Re: LED bar graph RE: Back pressure and torque Re: LED bar graph Renault FI? See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: "Mike Palmer" Date: Thu, 28 Aug 1997 08:24:17 EST5DST Subject: Re: Microcontrollers used in OEM systems > From: Matt Sale > Subject: Re: Microcontrollers used in OEM systems > > Actually, when you spread the cost over several million parts > per year, it makes quite a bit of sense to spend the extra time > effort and money to create a custom derivative. Remember too <*snip*> > isn't free (despite what Mickeysoft thinks). Adding parts to > boards to get functions that can be up-integrated wastes board > space and incurs extra costs for the additional parts. > Your point is well taken. Mind you, the P4 ECM PCB looks like it's got plenty of room for more stuff...it's not dense at all :) > You'd be amazed at how many 68300 family and TI parts we've > commissioned, I know I am. Every electronic box in a car has > a micro, or so it seems. The radio, ABS, air-bag, remote > keyless entry, instrument cluster, HVAC control, and ECM > each gets its own micro, at least in the high-end cars. Each > box has a unique set of requirements, and a price/value. > So the beancounter legend is real!...I thought that was just an old wives tale: "If you can save $0.02, make it so!" But seriously, the HC11 as it comes from Motorola can be had with an 8-channel A/D converter and SCI built in. Why then does the P4 seem to require a separate UART device and separate A/D converters? If cost minimalization was paramount, surely a few cheesy signal conditioners (a few op amps, caps and resistors) would have been cheaper than spreading block functionality (i.e. SCI, A/D etc) around the board in separate chunks of silicon and the effort required to route the PCB and place the parts... ...well, of course it wasn't, otherwise the (what I imagine were) extensive cost analysis studies undertaken be GM/Delco as to the unit cost of, say, a P4 would have fleshed this out. This is quite fascinating and I thank you for taking the time. - - Mike - ------------------------------------------ 1994 Probe GT Leather/PMoonroof/5-speed "You'll laugh, you'll cry, you'll hurl..." - ------------------------------------------ ------------------------------ From: Rich Mauruschat Date: Thu, 28 Aug 1997 13:09:32 +0100 Subject: non-EFI crap >Wed, 27 Aug 1997 23:06:04 -0700, Terry Martin wrote:- >Can someone refer me to an active group concerned with EFI, DYI or not, >and alternate fuels, or better yet modification of existing fuels to >better function with existing EFI systems? >That way I'll get out of your face :-) >Terry Terry, I'm sure everyone would be very grateful if you'd just get out of our face anyway! Thanks for the suggestion. Rich. ------------------------------ From: swagaero Date: Thu, 28 Aug 1997 05:51:42 -0700 Subject: Re: is their Henry J Roden wrote: > > On Wed, 27 Aug 1997 18:47:37 -0700 swagaero writes: > >Anyone on this list working on a sequentional fuel injection?? > > > > > > > > ----|------||------|---- > > --|------[]------|-- > > 0/ \0 > > > > > >Steve Parkman > >www.flash.net/~swagaero > > Thanks for the responses. I am looking to expand what I have done with the batch fired Motorola 68HC11-9 system (GEO STORM) Yes it's the only way GM has a lot more money for research then I do. I am trying to gain the few presious HP that Sequential will give you and still make it run cleaner Get serious no I not putting a cat on my airplane. I want to be able to run a 2, 3, 4, 6 cylinder engine off of one ECM using one program as I have done with my last project. Yes it does work and typically ite HC without a cat are under 10 ppm at idle. My old system is the same one that CB Performance used to get their CARB# for a modified VW. I sold out cheap on that one. What I would like is if some one has a working opinion on how to fake the ecm into seeing the correct amount of cylinders per rev. The problem is putting 1 crank and two cam sensors and go to six cylinder from a 2 cylinder. Think on that one. Steve Parkman ------------------------------ From: Matt Sale Date: Thu, 28 Aug 1997 08:18:00 -0500 (EST) Subject: Re: Microcontrollers used in OEM systems > > Your point is well taken. Mind you, the P4 ECM PCB looks like it's > got plenty of room for more stuff...it's not dense at all :) Depends on what you mean by dense :-) (pun intended). > > > But seriously, the HC11 as it comes from Motorola can be had with an > 8-channel A/D converter and SCI built in. Why then does the P4 seem > to require a separate UART device and separate A/D converters? If > cost minimalization was paramount, surely a few cheesy signal > conditioners (a few op amps, caps and resistors) would have been > cheaper than spreading block functionality (i.e. SCI, A/D etc) around > the board in separate chunks of silicon and the effort required to > route the PCB and place the parts... > I'm a little rusty on which year each ECM was designed, so I'm not even sure the P4 is an HC11. And no, many of the earlier systems don't use high-density PC boards, multi-layer boards are expensive too. Like you surmised, the cost tradeoff analysis is extensive, and because technology changes so rapidly, the best answer changes each year. However, the auto companies (not just GM) don't want to change their boxes every year, so a box designed in 1985, introduced in 1988/9 (with 1985 technology) could still be in production. I'm exagerating a little, but not much :-(. - -- Matthew D. Sale, IC Development Engineer, Delco Electronics Corp. msale@xxx.net/~msale '69 Mustang 351W 5-spd (13.464@xxx. All responses are my own and should not be mistaken for those of Delco Electronics or General Motors. ------------------------------ From: James Boughton Date: Thu, 28 Aug 1997 09:16:39 -0400 Subject: RE: Backpressure and torque For an excellent reference on this subject try "The Scientific Design of Exhaust and Intake Systems." All of my belongings are in boxes from moving so I don't remember the author, but it is worth reading. Jim Boughton boughton@xxx.net - ---------- From: Keven D. Coates[SMTP:keven@xxx.com] Sent: Wednesday, August 27, 1997 7:17 PM To: Bronco Group; Tom Cloud; diy_efi@xxx.edu; EEC-EFIList Subject: Backpressure and torque Tom wrote, >I keep hearing that the lack of exhaust back pressure >might be the cause of my lack of low-end torque (which >I can get back by advancing the timing, BTW) but then >I've read that relieving exhaust back pressure **never** >hurts low-end torque -- only that the engine needs to be >set up for it .... that removing exhaust back pressure >**always** increases torque and hp at **all** rpm's -- >and I've seen dyno curves to support that claim. I can't help but involve myself needlessly in a purely theoretical claim, so here it goes: I would disagree with the "always" and "all" words, with the clarification that what causes backpressure at higher rpms will sometimes mean higher exhaust velocity at lower rpms. When I had the stock '68 manifolds on my mustang (with a big cam, performer manifold, etc.) it had more backpressure for sure, but there is more. It had small exhaust manifold ports, and so had very high exhaust velocity. This caused it to idle much better, and very low rpm torque was slightly better. When I switched to 1 5/8" headers, the idle and very low rpm suffered. Why? Small primary runners, such as a a stock exhaust manifold, will create back pressure at higher rpms, but at lower rpms will create negative pressure waves from the high velocity of the air pulses going into a small runner. So, many stock manifolds will actually reduce backpressure at lower rpms (comparitive to a larger tube system), and therefore cause more torque at those rpms when compared with bigger primary headers. Back pressure can also cause more torque at lower rpms by slowing the fuel/air mixture from crossing right from the intake valve to the exhaust valve during valve overlap. This causes the same affect as closing the exhaust valve earlier. It will increase gas mileage (at that rpm) and torque by filling the cylinder more completely and not wasting as much fuel/air. Ferrari decided that an adjustable backpressure system was preferable over the increased complexity another system in their 355 (the one after the testarossa, whatever number that was). They found that they could increase low rpm torque through adjustable backpressure. Unfortunately the other affect of backpressure, whether it is caused by small primaries or other restriction is killing all higher rpm operation. My engine would barely rev to 5500 rpms with the '68 manifolds and the single 2" exhaust. After I replaced it with headers and dual 2.5" pipes, it would happily rev to 6500 rpm, with much more high rpm power. The same is true of intake manifolds to an even greater extent. The longer high velocity runners of the stock mustang manifold will almost always will low rpm torque battles with any bigger tube/shorter tube manifolds because of the high velocity ram effect of the intake pulses. But, it is too restrictive at higher rpms to make the horsepower of some of the other intakes. It's all a trade off, as usual. Well, that's it for my theoretical soap box. Hope you all enjoyed it! Best Regards, Keven Coates '68 stang Texas Instruments ------------------------------ From: John Hess Date: Thu, 28 Aug 1997 08:59:12 -0500 Subject: RE: Back pressure and torque > ---------- > From: Keven D. Coates[SMTP:keven@xxx.com] > Sent: Wednesday, August 27, 1997 6:17 PM > To: Bronco Group; Tom Cloud; diy_efi@xxx.edu; > EEC-EFIList > Subject: Backpressure and torque > > Tom wrote, > > >I keep hearing that the lack of exhaust back pressure > >might be the cause of my lack of low-end torque (which > >I can get back by advancing the timing, BTW) but then > >I've read that relieving exhaust back pressure **never** > >hurts low-end torque -- only that the engine needs to be > >set up for it .... that removing exhaust back pressure > >**always** increases torque and hp at **all** rpm's -- > >and I've seen dyno curves to support that claim. > > I can't help but involve myself needlessly in a purely theoretical > claim, so > here it goes: > > I would disagree with the "always" and "all" words, with the > clarification that > what causes backpressure at higher rpms will sometimes mean higher > exhaust > velocity at lower rpms. > Come on, use examples (i.e. a potato stuffed up the tailpipe would DEFINITELY increase back pressure at higher RPMs and would NOT increase exhaust velocity at ANY RPM). > When I had the stock '68 manifolds on my mustang (with a big cam, > performer > manifold, etc.) it had more backpressure for sure, but there is more. > It had > small exhaust manifold ports, and so had very high exhaust velocity. > This > caused it to idle much better, and very low rpm torque was slightly > better. > When I switched to 1 5/8" headers, the idle and very low rpm suffered. > > Why? Small primary runners, such as a a stock exhaust manifold, will > create > back pressure at higher rpms, but at lower rpms will create negative > pressure > waves from the high velocity of the air pulses going into a small > runner. So, > many stock manifolds will actually reduce backpressure at lower rpms > (comparitive to a larger tube system), and therefore cause more torque > at those > rpms when compared with bigger primary headers. > Actually, it has more do with pressure waves traveling at speeds governed by the diameter and length of the header than back pressure; but, we will accept this explanation. > Back pressure can also cause more torque at lower rpms by slowing the > fuel/air > mixture from crossing right from the intake valve to the exhaust valve > during > valve overlap. This causes the same affect as closing the exhaust > valve > earlier. It will increase gas mileage (at that rpm) and torque by > filling the > cylinder more completely and not wasting as much fuel/air. > > Ferrari decided that an adjustable backpressure system was preferable > over the > increased complexity another system in their 355 (the one after the > testarossa, > whatever number that was). They found that they could increase low > rpm torque > through adjustable backpressure. > > Unfortunately the other affect of backpressure, whether it is caused > by small > primaries or other restriction is killing all higher rpm operation. > My engine > would barely rev to 5500 rpms with the '68 manifolds and the single 2" > exhaust. > After I replaced it with headers and dual 2.5" pipes, it would happily > rev to > 6500 rpm, with much more high rpm power. > > The same is true of intake manifolds to an even greater extent. The > longer > high velocity runners of the stock mustang manifold will almost always > will low > rpm torque battles with any bigger tube/shorter tube manifolds because > of the > high velocity ram effect of the intake pulses. But, it is too > restrictive at > higher rpms to make the horsepower of some of the other intakes. > > It's all a trade off, as usual. Well, that's it for my theoretical > soap box. > Hope you all enjoyed it! > > Best Regards, > Keven Coates > '68 stang > Texas Instruments > The whole intent of those of us who caution against significantly changing the back pressure in an engine is that one really needs to determine the usage (and the resulting requirements) before one jerks any singular part of the system around. Back pressure changes (on a modern fuel injected engine) can have DRASTIC effects on what your O2 sensor THINKS it is seeing. Indeed, low enough back pressures (on unheated O2 sensors) can prevent the system from ever going closed loop! If one is simply measuring static back pressure, one is obviously missing the point. In an engine, what is sometimes referred to as back pressure at high RPMs can actually be measured as a NEGATIVE pressure at some specific lower RPMs (at the exhaust port). The term is commonly misused solely as a function of RPM. Back pressure will actually exert the same positive pressure at all speeds. The tuning of the port will determine if more pressure is placed on the source of the back pressure, thus minimizing its results. ------------------------------ From: swagaero Date: Wed, 27 Aug 1997 02:17:40 -0700 Subject: Re: Microcontrollers used in OEM systems Matt Sale wrote: > > > > > On this note, anybody ever figured out what some of the registers in > > the HC11 at $1040 and above are used for? How about those regs at, > > say, $1001 or $1006 etc that are mysteriously labelled "reserved" > > in the data sheets. Are these register locations left to the > > discretion of the Delcos and the NDs of the world to do as they > > please or is there a universal functionality associated with them? > > > > > Depends on the hc11 derivative. Each derivative has its own > memory map (A8, F1, K4, E9, ...). "Reserved" generally means > unimplemented. If you try to read one, > you might get $FF, or you might get an address back, depending > on the addressing mode & what was last driven on the internal > data bus. > > And yes, there are application specific hc11 derivatives that > are not available on the general market. > > -- > Matthew D. Sale, IC Development Engineer, Delco Electronics Corp. > msale@xxx.net/~msale > '69 Mustang 351W 5-spd (13.464@xxx. > > All responses are my own and should not be mistaken > for those of Delco Electronics or General Motors. 99% of the reserved addresses are not connected to anything I know I have chased a lot of them I wish Motorola would be so kind as to let us hackers have a road map?? ------------------------------ From: swagaero Date: Wed, 27 Aug 1997 02:22:31 -0700 Subject: Re: Microcontrollers used in OEM systems Matt Sale wrote: > > > > > Your point is well taken. Mind you, the P4 ECM PCB looks like it's > > got plenty of room for more stuff...it's not dense at all :) > > Depends on what you mean by dense :-) (pun intended). > > > > > > But seriously, the HC11 as it comes from Motorola can be had with an > > 8-channel A/D converter and SCI built in. Why then does the P4 seem > > to require a separate UART device and separate A/D converters? If > > cost minimalization was paramount, surely a few cheesy signal > > conditioners (a few op amps, caps and resistors) would have been > > cheaper than spreading block functionality (i.e. SCI, A/D etc) around > > the board in separate chunks of silicon and the effort required to > > route the PCB and place the parts... > > > I'm a little rusty on which year each ECM was designed, so I'm > not even sure the P4 is an HC11. And no, many of the earlier > systems don't use high-density PC boards, multi-layer > boards are expensive too. Like you surmised, the cost tradeoff > analysis is extensive, and because technology changes so rapidly, > the best answer changes each year. However, the auto companies > (not just GM) don't want to change their boxes every year, so > a box designed in 1985, introduced in 1988/9 (with 1985 technology) > could still be in production. I'm exagerating a little, but not > much :-(. > > -- > Matthew D. Sale, IC Development Engineer, Delco Electronics Corp. > msale@xxx.net/~msale > '69 Mustang 351W 5-spd (13.464@xxx. > > All responses are my own and should not be mistaken > for those of Delco Electronics or General Motors. If you will take another look at what GM has been doing with Motorola you will find EEprom built into the 68hc whaterver version along with a new rom mask just about every year since 1990 now if they would only update the northstar. Steve Parkman flash.net/~swagaero ------------------------------ From: Tom Cloud Date: Thu, 28 Aug 1997 09:30:45 -0500 Subject: LED bar graph anyone know a part no. for an LED bar graph that takes 0 to 1 volt or such as an input ??? I know they're out there, have used them long, long ago .... but now can't find one. This is not a plain bar graph assembly -- it would be an integrated circuit voltage/level indicator. thanks, Tom Cloud Why don't sheep shrink when they get wet ? ------------------------------ From: "Michael D. Porter" Date: Thu, 28 Aug 1997 08:31:45 -0700 Subject: Re: Backpressure and torque James Boughton wrote: > > For an excellent reference on this subject try "The > Scientific Design of Exhaust and Intake Systems." > All of my belongings are in boxes from moving so > I don't remember the author, but it is worth reading. > The authors are Philip Smith and John Morrison. I have the last (third) 1972 edition, but as far as I know, the book is still being reprinted and is available from Robert Bentley, Inc. Cheers. - -- My other Triumph runs, but.... ------------------------------ From: swagaero Date: Wed, 27 Aug 1997 03:05:14 -0700 Subject: Re: Back pressure and torque John Hess wrote: > > > ---------- > > From: Keven D. Coates[SMTP:keven@xxx.com] > > Sent: Wednesday, August 27, 1997 6:17 PM > > To: Bronco Group; Tom Cloud; diy_efi@xxx.edu; > > EEC-EFIList > > Subject: Backpressure and torque > > > > Tom wrote, > > a modern fuel injected engine) can have DRASTIC effects on what your O2 > sensor THINKS it is seeing. Indeed, low enough back pressures (on > unheated O2 sensors) can prevent the system from ever going closed loop! I think you need to go back to the books on this one an O2 sensor is not looking at pressure but a voltage generated by tempeture which varies by the oxy content in the exhaust my exhaust system is only 6" past the o2 sensor and it does a ful voltage scan within 18 sec after startup. That also includes using 100 low lead av fuel. Steve Parkman ------------------------------ From: Chief Date: Thu, 28 Aug 1997 11:18:08 -0400 Subject: Off topic, real brief I'm interested in materials science issues in racing engines or components. Does anybody know any source of information or where I might start to find out current problems, research issues, etc. Engine teardown after races would be very interesting and applicable also. Thanks and please reply offline. We now return to your regularly scheduled DIY-EFI discussion. Ed Hilker aka "Chief" 84'SS - 700R4 ------------------------------ From: garfield@xxx.com (Garfield) Date: Thu, 28 Aug 1997 15:32:11 GMT Subject: Re: Backpressure and torque On Thu, 28 Aug 1997 09:16:39 -0400, James Boughton wrote: >For an excellent reference on this subject try "The >Scientific Design of Exhaust and Intake Systems." >All of my belongings are in boxes from moving so >I don't remember the author, but it is worth reading. > >Jim Boughton Thank you soooo much, Jim, for posting this info. References in this area are scarce as hen's teeth. Could it be: Scientific Design of Exhaust & Intake Systems by John C. Morrison, Philip Hubert Smith 3rd Edition=20 Paperback, 274 pages Published by Robert Bentley, 1972 ISBN: 0837603099 I looked it up on www.amazon.com , a GREAT place to order books over the net, if anyone wasn't aware of them. List: $22.95 ~ Our Price: $18.36=20 Availability: Usually ships within 2-3 days. Also, they have a "review" piece appended to this book's entry, which may point to some other good resources as well. Anyone care to comment on the other stuff this "reviewer" mentions below?: "This book is one of only a few in this field, and for that reason, it is worth reading. it is however showing signs of age, and doesn't provide a lot of hands-on info for those who want to modify their own engines. As a starting point, I would recommend AG Bell's books or Dalton's "Practical gas flow" if your interests are in this area." [end of quote] Garfield Also, if anyone can recommend a good read on Cam design, I'd sure appreciate it. ------------------------------ From: Doug Yip Date: Thu, 28 Aug 1997 08:36:27 -0700 Subject: Re: CDI, accelerometer Stuart Baly wrote: > > A couple of things of interest to Aus. list members: > > Sept.97 Electronics Australia has a small project based on the Analog > Devices ADXL05? accelerometer. I remember a thread about these a > while ago. The evaluation kit is A$97 for two units, two circuit > boards to mount them on, and datasheets. > > Sept. 97 Silicon Chip magazine has a multiple spark discharge CDI > unit as a project. The kit is about A$100 from Dick Smith. > > Stuart. > ======================================================== > Stuart Baly (s.baly@xxx.au) > Technical Officer > Cape Grim Baseline Air Pollution Station > '71 Datsun 510, '81 Yamaha RD350LC, '89 Kawasaki GPz900R > ======================================================== I'm not sure that Silicon Chip magazine is available in North America. Can you scan the article and send me a copy (or provide information on how to contact Dick Smith)? Best Regards, - -- Doug Yip Digicon Engineering Incorporated http://mindlink.net/digicon ------------------------------ From: John Hess Date: Thu, 28 Aug 1997 11:12:03 -0500 Subject: RE: Back pressure and torque I DID go to the books. Back pressure (and flow) effects the exhaust temperature. The exhaust temperature of a free flowing exhaust can have an effect on the O2 sensor, since most depend on the exhaust to heat them up into their operating range. I have consistently had troubles with cars with header systems not going into closed loop, simply because the O2 sensor didn't get hot enough. That is why I now install electrically heated O2 sensors on cars with headers. > ---------- > From: swagaero[SMTP:wb7omm@xxx.net] > Sent: Wednesday, August 27, 1997 5:05 AM > To: diy_efi@xxx.edu > Subject: Re: Back pressure and torque > > John Hess wrote: > > > > > ---------- > > > From: Keven D. Coates[SMTP:keven@xxx.com] > > > Sent: Wednesday, August 27, 1997 6:17 PM > > > To: Bronco Group; Tom Cloud; diy_efi@xxx.edu; > > > EEC-EFIList > > > Subject: Backpressure and torque > > > > > > Tom wrote, > > > > > a modern fuel injected engine) can have DRASTIC effects on what your > O2 > > sensor THINKS it is seeing. Indeed, low enough back pressures (on > > unheated O2 sensors) can prevent the system from ever going closed > loop! > > I think you need to go back to the books on this one an O2 sensor is > not > looking at pressure but a voltage generated by tempeture which varies > by > the oxy content in the exhaust my exhaust system is only 6" past the > o2 > sensor and it does a ful voltage scan within 18 sec after startup. > That > also includes using 100 low lead av fuel. > > > Steve Parkman > ------------------------------ From: Tom Cloud Date: Thu, 28 Aug 1997 11:14:41 -0500 Subject: interesting kits -- automotive app check out http://www.ramseyelectronics.com/prod07.htm they have some clever electronic kits .... among them: "personal speed radar" kit that lets you clock the speed of objects -- has a hand-held "gun" ($100) and the one I'm interested in: "microwave motion detector" so I can pitch those danged IR motion sensors that control some of my outside lights ($20) Tom Cloud Why don't sheep shrink when they get wet ? ------------------------------ From: garfield@xxx.com (Garfield) Date: Thu, 28 Aug 1997 16:23:38 GMT Subject: Tuning Book List =46ollowing up on Jim's lead, here are the books that the "amazon reviewer" was apparently refering to: **** Scientific Design of Exhaust & Intake Systems by John C. Morrison, Philip Hubert Smith 3rd Edition=20 Paperback, 274 pages Published by Robert Bentley Publication date: June 1972 ISBN: 0837603099=20 **** Practical Gas Flow : Techniques for Low-Budget Performance Tuning by John Dalton Paperback Published by Motorbooks International Publication date: December 1996 ISBN: 1899870083=20 List: $21.95 ~ Our Price: $21.95 Availability: This item is currently on back order. **** Two-Stroke Performance Tuning in Theory and Practice=20 by A. Graham Bell Hardcover Published by Haynes Pubns Publication date: June 1983 ISBN: 0854293299=20 List: $24.95 ~ Our Price: $24.95 Availability: usually ships within 2-3 days. **** Four-Stroke Performance Tuning in Theory and Practice by A. Graham Bell 1 Edition=20 Hardcover, 254 pages Published by Haynes Pubns Publication date: 1, 1988 ISBN: 0854292756=20 List: $32.95 ~ Our Price: $32.95 Availability: This item is currently on back order.=20 **** Modern Engine Tuning by A. Bell Hardcover, 256 pages Published by Haynes Pubns Publication date: September 1, 1997 ISBN: 0854299785=20 List: $34.95 ~ Our Price: $24.47=20 Not Yet Available: You may still order this book. **** Tuning : New Generation Engines for Power and Economy by A. Graham Bell Published by Haynes Pubns Publication date: September 1989 ISBN: 0854296093=20 Availability: This title is out of print. Enjoy, Garfield ------------------------------ From: Tom Cloud Date: Thu, 28 Aug 1997 12:08:43 -0500 Subject: RE: interesting kits -- automotive app I received the following response about Ramsey Electronics (who has the kits I posted) -- so BEWARE !! (I've never traded with them) >I would consider the below as a 'bag of parts' (and not very good parts at >that). I needed a motor speed controller and bought their kit, thinking I would >save some time. Their circuit, using two 555s and an IRF510 mosfet, would not, >and could not power the motor at 100% (full on). The parts didn't fit the >board, and the instructions said things like "insert either the 10 uf or 16 uf >cap in position C13". In other words, they sent you what ever they had, and let >ytou know about it. I also made the mistake of buying ther $150 6m transceiver >kit. Same complaints. The ceramic caps were the cheapest quality I've ever >seen, and when put in the PCB (with the spacing too far apart) would crack the >caps. I was aware of the quality when I bought it, though. I had intended on >buying it as a 'bag of parts' and hevily modifing it to suit my needs. Well, I >lost the sch., and they would not send me another one!! "We cant just send you >one without you paying for it, you will have to send $5 for another manual". I >tried to explain that trancevier manuals cost $10, not $5, and when you buy one >(like I did alreay) you don't even get the sch. She didn't understand that I >already had two manuals that I paid for and no sch, and I'd be damned if I was >going to buy a third. > Well, with that off my chest, I'm not recomending that you don't buy the kit >below, just be forwarned. I've ordered kits in the past, and I'm sure I'll >order kits in the future. Oh, and they will sell manuals for $5, with the $5 >refundable if you buy the kit. I've bought a lot of manuals (just to see how >things work) and will probably buy more in the future. > > >> >> check out >> >> http://www.ramseyelectronics.com/prod07.htm >> >> >> they have some clever electronic kits .... among them: >> >> "personal speed radar" kit that lets you clock the >> speed of objects -- has a hand-held "gun" ($100) >> >> and the one I'm interested in: >> "microwave motion detector" so I can pitch those >> danged IR motion sensors that control some of >> my outside lights ($20) Tom Cloud Why don't sheep shrink when they get wet ? ------------------------------ From: "Corey L. Cole" Date: Thu, 28 Aug 1997 10:39:00 -0700 Subject: Re: Back pressure and torque John Hess wrote: > > I DID go to the books. Back pressure (and flow) effects the exhaust > temperature. The exhaust temperature of a free flowing exhaust can have > an effect on the O2 sensor, since most depend on the exhaust to heat > them up into their operating range. I have consistently had troubles > with cars with header systems not going into closed loop, simply because > the O2 sensor didn't get hot enough. That is why I now install > electrically heated O2 sensors on cars with headers. I always thought that the problem with O2 sensors and fabricated manifolds was that the thin wall tubing rejected heat much faster than the cast type. Furthermore, I'd also heard that ceramic coatings and thermal wraps can alleviate or eliminate those problems (plus keep you engine compartment cooler) - -- ============================================================================== Corey L. Cole | I was standing on the side of the road, M/S 19-HH | rain falling on my shoe. E-mail: corey.l.cole@xxx.com | I was heading for the east coast, Phone: 206-662-3596 | Lord knows I've paid some dues. | Tangled up in blue. ============================================================================== Disclaimer: If I'm not speaking FORTRAN, I'm not speaking for Boeing. ------------------------------ From: swagaero Date: Thu, 28 Aug 1997 11:57:45 -0700 Subject: Re: Back pressure and torque Corey L. Cole wrote: > > John Hess wrote: > > > > I DID go to the books. Back pressure (and flow) effects the exhaust > > temperature. The exhaust temperature of a free flowing exhaust can have > > an effect on the O2 sensor, since most depend on the exhaust to heat > > them up into their operating range. I have consistently had troubles > > with cars with header systems not going into closed loop, simply because > > the O2 sensor didn't get hot enough. That is why I now install > > electrically heated O2 sensors on cars with headers. > > I always thought that the problem with O2 sensors and fabricated manifolds > was that the thin wall tubing rejected heat much faster than the cast type. > Furthermore, I'd also heard that ceramic coatings and thermal wraps can > alleviate or eliminate those problems (plus keep you engine compartment > cooler) > I love to see it when everbody starts to think remember it's the amount of heat that makes a o2 sensor work Put the sensor as close to the ports as possible with batch fired use just one cylinder and put it 2 inches off the head wit sequentional put where all the runners come together. Steve Parkman > -- > ============================================================================== > Corey L. Cole | I was standing on the side of the road, > M/S 19-HH | rain falling on my shoe. > E-mail: corey.l.cole@xxx.com | I was heading for the east coast, > Phone: 206-662-3596 | Lord knows I've paid some dues. > | Tangled up in blue. > ============================================================================== > Disclaimer: If I'm not speaking FORTRAN, I'm not speaking for Boeing. ------------------------------ From: "Dave J. Andruczyk" Date: Thu, 28 Aug 1997 15:10:25 -0400 (EDT) Subject: Re: LED bar graph > anyone know a part no. for an LED bar graph that takes 0 to > 1 volt or such as an input ??? I know they're out there, have > used them long, long ago .... but now can't find one. This > is not a plain bar graph assembly -- it would be an integrated > circuit voltage/level indicator. > national semiconductor, makes it LM3914 (15, and 16) the x15 and x16 version have a different scale, x14 is linear, x15 is audio x16 is log. the basic linear circuit is sensitive from 0 to 1.2 volts. and they are easily stackable. Look on their website www.natsemi.com, and they may even send yo free samples. ( I even got free databooks from them..) Dave ------------------------------ From: John Hess Date: Thu, 28 Aug 1997 14:46:26 -0500 Subject: RE: Back pressure and torque Place a quick call to John Lingenfelter. > ---------- > From: Corey L. Cole[SMTP:corey.l.cole@xxx.com] > Sent: Thursday, August 28, 1997 12:39 PM > To: diy_efi@xxx.edu > Subject: Re: Back pressure and torque > > John Hess wrote: > > > > I DID go to the books. Back pressure (and flow) effects the exhaust > > temperature. The exhaust temperature of a free flowing exhaust can > have > > an effect on the O2 sensor, since most depend on the exhaust to heat > > them up into their operating range. I have consistently had > troubles > > with cars with header systems not going into closed loop, simply > because > > the O2 sensor didn't get hot enough. That is why I now install > > electrically heated O2 sensors on cars with headers. > > I always thought that the problem with O2 sensors and fabricated > manifolds > was that the thin wall tubing rejected heat much faster than the cast > type. > Furthermore, I'd also heard that ceramic coatings and thermal wraps > can > alleviate or eliminate those problems (plus keep you engine > compartment > cooler) > > -- > ====================================================================== > ======== > Corey L. Cole | I was standing on the side of the > road, > M/S 19-HH | rain falling on my shoe. > E-mail: corey.l.cole@xxx.com | I was heading for the east coast, > Phone: 206-662-3596 | Lord knows I've paid some dues. > | Tangled up in blue. > ====================================================================== > ======== > Disclaimer: If I'm not speaking FORTRAN, I'm not speaking for Boeing. > ------------------------------ From: Matt Sale Date: Thu, 28 Aug 1997 14:48:50 -0500 (EST) Subject: Re: LED bar graph > > > anyone know a part no. for an LED bar graph that takes 0 to > > 1 volt or such as an input ??? I know they're out there, have > > used them long, long ago .... but now can't find one. This > > is not a plain bar graph assembly -- it would be an integrated > > circuit voltage/level indicator. > > > > national semiconductor, makes it LM3914 (15, and 16) the x15 and x16 > version have a different scale, x14 is linear, x15 is audio x16 is log. > Doesn't Digikey still sell a module with the LM3914 + LED's on a little ckt board? - -- Matt ------------------------------ From: Paul Witek Date: Thu, 28 Aug 1997 15:00:22 -0500 (CDT) Subject: Renault FI? Hey gang- So, I'm in the u-pull salvage yard, pulling Bosch bits off of various cars for dirt cheap (Weber throttle body - $10 - woohoo!) when I come across a Renault Medallion. Now, most of the Renaults I've seen either have a TBI system or Bosch L-Jet, but this one had a funky cast cover over the a/f meter that read "Injection Renault". It was definitely a MPI system - anyone know what the specs are on it? Is it a derivative of something else? For the curious, I'm currently in the process of gathering bits to adapt a Bosch L-Jetronic system from a California-spec Renault Alliance 1.4 liter to my 1962 Alfa Romeo Giulietta 1.3 liter. The beauty part is that the nice Weber throttle body drops right into place on the stock intake manifold, a direct replacement for the stock Solex downdraft. Now I just need to figure out how to modify the manifold for the injectors.... Paul Witek zagato@xxx.net Shemp Mo-Din Italian Motorsports http://www.evansville.net/~zagato ------------------------------ End of DIY_EFI Digest V2 #294 ***************************** 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".