DIY_EFI Digest Thursday, 7 January 1999 Volume 04 : Number 016 In this issue: Wide range 02 sensor Re: Water Injection Thread Re: Turbo header design Re: Vats Re: Injector Duty Monitor Re: Wide Band Lambda Sensor, where can I locate?Walter? Re: 180 degree headers WAS:Re: Turbo header design RE: Injector Duty Monitor Re: GM P6 PCM Info Re: Turbo header design Re: Turbo header design Re: Turbo header design Re: Water Injection Thread [now U joints] Re: Wide Band Lambda Sensor, where can I locate?Walter? FI system opinion? Re: Injector Duty Monitor Re: Turbo header design Re: Injector Duty Monitor Re: Water Injection Thread [now U joints] 128K vs 256K Proms in one ecm RE: FI system opinion? Re: Injector Duty Monitor Turbo header design Re: Injector Duty Monitor Re: Delco 639 Fw: 128K vs 256K Proms in one ecm Re: FI system opinion? Re: Turbo header design See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: "Geoff Richards" Date: Thu, 24 Dec 1998 08:30:47 +1100 Subject: Wide range 02 sensor List When enquiring about purchase of wide range 02 sensor was told that it was only good for approx 50 hrs yet same sensor in car good for 100 000 k's more or less many more hours than 50 Am I missing something? ps: Any other mailing lists similar interests to this one can be recommended Thanks Geoff ------------------------------ From: Tom Sharpe Date: Thu, 07 Jan 1999 06:43:49 -0600 Subject: Re: Water Injection Thread Raymond C Drouillard wrote: > >Caddy used to use CV drive-shaft joints like that too--quieter and > >smoother, cuzza no accel/decel of the driveshaft as it rotates. There is > a > >little sphere and socket in the center that keeps 'em aligned. Mid '70's > >Chevy full-time 4x4 trucks used a similar joint at the transfer case end > of > >their front drive shaft, too. > > Do you have any idea where I can get such a critter? All early Broncos had them... Tom ------------------------------ From: "Gary Derian" Date: Thu, 7 Jan 1999 07:56:05 -0500 Subject: Re: Turbo header design A reasonably close approximation to true 180 deg. headers can be made with the old tri-Y approach. As Aaron wrote, true 180 would require merging 1-6, 8-5, 4-7, 3-2 which is difficult to make. Merging 1-5, 3-7, 4-6, 2-8 enables cylinder pairs to share an exhaust pipe without interfering and is relatively easy to build. This is common in high output European and Japanese V-8 engines. Ferrari, on the other hand, uses a flat crank to make a true 180 header easy. Formula 1 and CART V-8 engines also use flat cranks. Flat crank V-8's vibrate like 2 4cyl engines. A 90 degree crank V-8 has complete primary and secondary balance with only weights on the crank. Gary Derian - -----Original Message----- From: Aaron Willis To: diy_efi@xxx.edu> Date: Wednesday, January 06, 1999 6:29 PM Subject: Re: Turbo header design > >Clarence, > This is easily done with an inline four having a 1-3-4-2 firing order, >as you just pair cyl's 1-4 and 2-3 together. Commonly done in NA >headers and OEM manifolds too. However, true 180 degree headers on a V8 >typically take up a lot of space. > The only firing order i am familiar with is for a GM engine, which is >1-8-4-3-6-5-7-2. Picture the cyliders as two rows (which they are): > > 1 2 you can see that #1's 180 degree partner is #6, #8's > 3 4 is #5, #4's is #7 and #3's is #2. > 5 6 > 7 8 Obviously these are all on opposite banks, so the >pipes need to travel around the engine some distance to collect in a 180 >degree fashion. I really don't know much about whether the benifits >would outweigh the extra bulk and length of the exhaust system, but I >suspect not. > HOWEVER it must be said that this arrangement does offer a killer >sound in NA form! A gentleman in town has a '53 (?) Studebaker with a >406 Chevy in it, using standard NASCAR 180-degree headers collected into >a single exhaust, and it will raise the hair on the back of your neck. >Almost sounds like an exotic foreign supercar (or a flat-crank V8, come >to think of it) > >HTH > >Aaron > >ICQ # 27386985 ------------------------------ From: Ken Kelly Date: Thu, 07 Jan 1999 08:45:28 -0500 Subject: Re: Vats Peter, I am confused by your answer. I know that in the B & F-body the key connects to a security module or accessory computer that generates a pulsed signal. Older Vats used 30 Hz and the newer units are 50Hz. This signal is applied to an ECM or PCM pin and is necessary to get proper fuel flow. How is the vette different? Ken Peter Fenske wrote: > > Howday > > A vette is a different animal than a F body.. > > The ccm uses the 30/50 Hz signal and checks it. > If all ok a signal is sent on the data buss to the ecm.. > > Only way to do this is to set the vats bit off in the PCM.. > Good thing for 92 this is in a calpak not too hard to do > > take care:peter ------------------------------ From: "Bruce Plecan" Date: Thu, 7 Jan 1999 09:17:07 -0500 Subject: Re: Injector Duty Monitor If someone is going to build one, please contact me (off list), I'd like a couple, and it would be worth something to me to have them. (The measured on time style) Thanks Bruce ------------------------------ From: bearbvd@xxx.net (Greg Hermann) Date: Thu, 7 Jan 1999 07:17:50 -0700 Subject: Re: Wide Band Lambda Sensor, where can I locate?Walter? >Hi Guys! NGK (USA) is located in Michigan, and the last phone number that >I have for them is 1-810-489-0110. > > >The sensor harness connector utilizes 7 connections. Basically, it is a >6-wire sensor (as made for Horiba and others) plus one other terminal for a >compensation resistance. All accurate info, except that the current version of the harness/sensor uses five wires. The area code MAY have changed to 248. Ted Maatsura is the name of NGK's manager at that office. Regards, Greg ------------------------------ From: Eric Aos Date: Thu, 7 Jan 1999 07:34:10 -0800 Subject: Re: 180 degree headers WAS:Re: Turbo header design >> The only firing order i am familiar with is for a GM engine, which is >>1-8-4-3-6-5-7-2. Picture the cyliders as two rows (which they are): >> >> 1 2 you can see that #1's 180 degree partner is #6, #8's >> 3 4 is #5, #4's is #7 and #3's is #2. >> 5 6 >> 7 8 > >#1 and #6 are 180 degrees apart on the distributor, not the crank. #1 and #4 >are 180 degrees apart on the crank. Aren't they? What cylinders are grouped >together with NASCAR 180 degree headers? > >Jon > > > I think he meant 360 degrees--- :-) Don't forget the 90deg Bank Angle so with #6 following #4 by 90, it works out. ------------------------------ From: Mike Pitts Date: Thu, 7 Jan 1999 10:36:14 -0500 Subject: RE: Injector Duty Monitor Bruce and All, Check this out: http://www.radioshack.com/sw/swb/projects/stamp/pulse.htm never built it myself, but looks like it oughta work. - -----Original Message----- Bruce "CSH" Plecan mumbled something that sounded like: If someone is going to build one, please contact me (off list), I'd like a couple, and it would be worth something to me to have them. (The measured on time style) ------------------------------ From: "Bruce Plecan" Date: Thu, 7 Jan 1999 10:41:33 -0500 Subject: Re: GM P6 PCM Info - -----Original Message----- From: David A. Cooley To: diy_efi@xxx.edu> Date: Wednesday, January 06, 1999 2:02 AM Subject: GM P6 PCM Info Thanks, Bruce >Just uploaded the pinout for the GM P6 PCM to the incoming dir... >File name is: GM_P6_pin.rtf It's in Rich Text Format. > >=========================================================== > David Cooley N5XMT Internet: N5XMT@xxx.net > Packet: N5XMT@xxx. Member #7068 > I am Pentium of Borg...division is futile...you will be approximated. >=========================================================== > ------------------------------ From: Clarence Wood Date: Thu, 07 Jan 1999 10:52:20 -0600 Subject: Re: Turbo header design The tri-Y approach sounds more like the article that I read. In the article, there were collectors for each bank. Damn! I can't find the article! It is here, under a pile of other treasures, somewhere. Anyway, they talked about matching the cylinders on each bank to scavenge, put in short baffles that led into a cone shaped collector that narrowed into the exhaust pipe. Now, I hate to share my ignorance with you all, but I have ran into a problem understanding what is probably the most basic operation of a V8 engine. Here is what I did to determine what cylinders should be matched: Firing order 1 8 4 3 6 5 7 2 Stroke 1. P C I E P C I E (P=power,C=comp,I=intake,E=exht) 2. E P C I E P C I 3. I E P C I E P C 4. C I E P C I E P Why is cylinder #6 at a power stroke while cylinder #1 is also at a power stroke? I am trying to find out where each of the cylinders are, in their four stroke cycle, when cylinder #1 is at its Power stroke. What am I doing wrong?? Where is cylinder #6, in its stroke cycle, when cylinder #1 is on the power stroke? At 07:56 AM 1/7/99 -0500, you wrote: >A reasonably close approximation to true 180 deg. headers can be made with >the old tri-Y approach. As Aaron wrote, true 180 would require merging 1-6, >8-5, 4-7, 3-2 which is difficult to make. Merging 1-5, 3-7, 4-6, 2-8 >enables cylinder pairs to share an exhaust pipe without interfering and is >relatively easy to build. This is common in high output European and >Japanese V-8 engines. Ferrari, on the other hand, uses a flat crank to make >a true 180 header easy. Formula 1 and CART V-8 engines also use flat >cranks. > >Flat crank V-8's vibrate like 2 4cyl engines. A 90 degree crank V-8 has >complete primary and secondary balance with only weights on the crank. > >Gary Derian > >-----Original Message----- >From: Aaron Willis >To: diy_efi@xxx.edu> >Date: Wednesday, January 06, 1999 6:29 PM >Subject: Re: Turbo header design > > >> >>Clarence, >> This is easily done with an inline four having a 1-3-4-2 firing order, >>as you just pair cyl's 1-4 and 2-3 together. Commonly done in NA >>headers and OEM manifolds too. However, true 180 degree headers on a V8 >>typically take up a lot of space. >> The only firing order i am familiar with is for a GM engine, which is >>1-8-4-3-6-5-7-2. Picture the cyliders as two rows (which they are): >> >> 1 2 you can see that #1's 180 degree partner is #6, #8's >> 3 4 is #5, #4's is #7 and #3's is #2. >> 5 6 >> 7 8 Obviously these are all on opposite banks, so the >>pipes need to travel around the engine some distance to collect in a 180 >>degree fashion. I really don't know much about whether the benifits >>would outweigh the extra bulk and length of the exhaust system, but I >>suspect not. >> HOWEVER it must be said that this arrangement does offer a killer >>sound in NA form! A gentleman in town has a '53 (?) Studebaker with a >>406 Chevy in it, using standard NASCAR 180-degree headers collected into >>a single exhaust, and it will raise the hair on the back of your neck. >>Almost sounds like an exotic foreign supercar (or a flat-crank V8, come >>to think of it) >> >>HTH >> >>Aaron >> >>ICQ # 27386985 > > ------------------------------ From: "Clive Apps Techno-Logicals 416 510 0020" Date: Thu, 7 Jan 1999 12:15:39 -0500 (EST) Subject: Re: Turbo header design > > The tri-Y approach sounds more like the article that I read. In the article, there were collectors for each bank. Damn! I can't find the article! It is here, under a pile of other treasures, somewhere. Anyway, they talked about matching the cylinders on each bank to scavenge, put in short baffles that led into a cone shaped collector that narrowed into the exhaust pipe. > Now, I hate to share my ignorance with you all, but I have ran into a problem understanding what is probably the most basic operation of a V8 engine. Here is what I did to determine what cylinders should be matched: > > Firing order > 1 8 4 3 6 5 7 2 > Stroke > 1. P C I E P C I E (P=power,C=comp,I=intake,E=exht) > 2. E P C I E P C I > 3. I E P C I E P C > 4. C I E P C I E P > > Why is cylinder #6 at a power stroke while cylinder #1 is also at a power stroke? I am trying to find out where each of the cylinders are, in their four stroke cycle, when cylinder #1 is at its Power stroke. What am I doing wrong?? Where is cylinder #6, in its stroke cycle, when cylinder #1 is on the power stroke? you forgot the 90^ offste in the crank Clive ------------------------------ From: andy quaas Date: Thu, 7 Jan 1999 09:23:11 -0800 (PST) Subject: Re: Turbo header design I just saw an atricle in car craft (i think) where they did a header test. On naturally aspirated engines, the tri-y design header created more HP and torque across the operating range (on a very mild 350 SBC). I switched from hooker generic headers to doug thorley tri-Y and the performance boost was noticable. The first thing i noticed was the weird exhaust note! I didnt change pipes or mufflers when i switched, but the exhaust sounds completely different! Just some experience nfo. Andy - ---Clarence Wood wrote: > > The tri-Y approach sounds more like the article that I read. In the article, there were collectors for each bank. Damn! I can't find the article! It is here, under a pile of other treasures, somewhere. Anyway, they talked about matching the cylinders on each bank to scavenge, put in short baffles that led into a cone shaped collector that narrowed into the exhaust pipe. > Now, I hate to share my ignorance with you all, but I have ran into a problem understanding what is probably the most basic operation of a V8 engine. Here is what I did to determine what cylinders should be matched: > > Firing order > 1 8 4 3 6 5 7 2 > Stroke > 1. P C I E P C I E (P=power,C=comp,I=intake,E=exht) > 2. E P C I E P C I > 3. I E P C I E P C > 4. C I E P C I E P > > Why is cylinder #6 at a power stroke while cylinder #1 is also at a power stroke? I am trying to find out where each of the cylinders are, in their four stroke cycle, when cylinder #1 is at its Power stroke. What am I doing wrong?? Where is cylinder #6, in its stroke cycle, when cylinder #1 is on the power stroke? > > At 07:56 AM 1/7/99 -0500, you wrote: > >A reasonably close approximation to true 180 deg. headers can be made with > >the old tri-Y approach. As Aaron wrote, true 180 would require merging 1-6, > >8-5, 4-7, 3-2 which is difficult to make. Merging 1-5, 3-7, 4-6, 2-8 > >enables cylinder pairs to share an exhaust pipe without interfering and is > >relatively easy to build. This is common in high output European and > >Japanese V-8 engines. Ferrari, on the other hand, uses a flat crank to make > >a true 180 header easy. Formula 1 and CART V-8 engines also use flat > >cranks. > > > >Flat crank V-8's vibrate like 2 4cyl engines. A 90 degree crank V-8 has > >complete primary and secondary balance with only weights on the crank. > > > >Gary Derian > > > >-----Original Message----- > >From: Aaron Willis > >To: diy_efi@xxx.edu > >Date: Wednesday, January 06, 1999 6:29 PM > >Subject: Re: Turbo header design > > > > > >> > >>Clarence, > >> This is easily done with an inline four having a 1-3-4-2 firing order, > >>as you just pair cyl's 1-4 and 2-3 together. Commonly done in NA > >>headers and OEM manifolds too. However, true 180 degree headers on a V8 > >>typically take up a lot of space. > >> The only firing order i am familiar with is for a GM engine, which is > >>1-8-4-3-6-5-7-2. Picture the cyliders as two rows (which they are): > >> > >> 1 2 you can see that #1's 180 degree partner is #6, #8's > >> 3 4 is #5, #4's is #7 and #3's is #2. > >> 5 6 > >> 7 8 Obviously these are all on opposite banks, so the > >>pipes need to travel around the engine some distance to collect in a 180 > >>degree fashion. I really don't know much about whether the benifits > >>would outweigh the extra bulk and length of the exhaust system, but I > >>suspect not. > >> HOWEVER it must be said that this arrangement does offer a killer > >>sound in NA form! A gentleman in town has a '53 (?) Studebaker with a > >>406 Chevy in it, using standard NASCAR 180-degree headers collected into > >>a single exhaust, and it will raise the hair on the back of your neck. > >>Almost sounds like an exotic foreign supercar (or a flat-crank V8, come > >>to think of it) > >> > >>HTH > >> > >>Aaron > >> > >>ICQ # 27386985 > > > > > _________________________________________________________ DO YOU YAHOO!? Get your free @xxx.com ------------------------------ From: Jim Davies Date: Thu, 7 Jan 1999 10:31:09 -0800 (PST) Subject: Re: Water Injection Thread [now U joints] On Thu, 7 Jan 1999, Tom Sharpe wrote: > > >Caddy used to use CV drive-shaft joints like that too--quieter and > > >smoother, cuzza no accel/decel of the driveshaft as it rotates. There is > > a > > >little sphere and socket in the center that keeps 'em aligned. Mid '70's > > >Chevy full-time 4x4 trucks used a similar joint at the transfer case end > > of > > >their front drive shaft, too. > > > > Do you have any idea where I can get such a critter? > > All early Broncos had them... Tom > > CV joints made up from 2 standard cardan joints all have centering devices. there are two common brands- saginaw and spicer. For some reason, GM used a lot of spicers whereas others used the Saginaw. Go figure. Anyway, every domestic 4X4 that had the transfer case bolted to the transmission [and some that didnt] used a CV joint of this type on the front shaft at the T case end it seems to me. The saginaw type has a simpler but better [IMO] centering ball setup as compared to the spicer because it is less likely to die an unrepairable death. OTOH, the saginaw uses the frankenstein type plastic retaining setup for the cardan joints which is a problem if you dont have a torch... Many 70s GM cars also used the saginaw CV. Cheaper cars had one at the rear axle, while more expensive cars had two, one at either end of the driveshaft. If I had to choose, I would stay with the saginaw over the spicer because of the centering ball rebuildability thing. Of course, a Tripod or a Rzeppa will handle more angularity than either of the above... you could also dig up and use an old Mopar ball&trunnion joint, which will also handle more angularity than the saginaw or spicer, plus it is a plunge joint, so it handles the slipyoke problem, too. ------------------------------ From: "Walter Sherwin" Date: Thu, 7 Jan 1999 14:29:17 -0800 Subject: Re: Wide Band Lambda Sensor, where can I locate?Walter? Thanks Greg! Walt. - -----Original Message----- From: Greg Hermann To: diy_efi@xxx.edu> Date: Thursday, January 07, 1999 7:02 AM Subject: Re: Wide Band Lambda Sensor, where can I locate?Walter? >>Hi Guys! NGK (USA) is located in Michigan, and the last phone number that >>I have for them is 1-810-489-0110. >> >> >>The sensor harness connector utilizes 7 connections. Basically, it is a >>6-wire sensor (as made for Horiba and others) plus one other terminal for a >>compensation resistance. > >All accurate info, except that the current version of the harness/sensor >uses five wires. The area code MAY have changed to 248. Ted Maatsura is the >name of NGK's manager at that office. > >Regards, Greg > > ------------------------------ From: "Aaron Andrews" Date: Thu, 7 Jan 1999 11:31:23 -0800 Subject: FI system opinion? Just wanted to get anyone's opinion on the Racetech SDS FI System that is a complete programmable system for $650, add $350 for a distributorless ignition and engine management system? TIA Aaron ------------------------------ From: "Walter Sherwin" Date: Thu, 7 Jan 1999 14:34:09 -0800 Subject: Re: Injector Duty Monitor > >DUTY CYCLE is calculated, by meters, as the percentage of time the >circuit is "asserted" between event triggers. This means that the >"period" is measured from injector opening to injector opening, or >injector closing to injector closing. The percentage of this period >occupied by the "asserted" mode, or injector energized, is read as DUTY >CYCLE. As such, there is NO requirement to know the firing mode of the >engine, or anything else. It WILL be accurate. >The DUTY RATIO is the ratio of time on vs time off and is generally not >used. This would be stated as 8:2, not 80%. Even with duty ratio, the >effect is the same - conversion is direct as long as the 2 numbers >(before and after colon) add up to 10. > >I fail to see how the injection mode can affect this. ------------------------------ From: bearbvd@xxx.net (Greg Hermann) Date: Thu, 7 Jan 1999 13:21:21 -0700 Subject: Re: Turbo header design FOR THIS PARTICULAR V-8> (IT HAS A 90 degree crank) > Firing order > 1 8 4 3 6 5 7 2 With this firing order, take every other cylinder in the firing order if you want 180 degree (crank rotation) spaced pulses into a pair of 4 into 1 collectors: 1, 4, 6, & 7 go into one collector (two end cylinders from one bank, and the two center cylinders from the other bank. 8, 3, 5, & 2 go into the other collector. (the two end cylinders on the other side, and the two middles from the first side. If you want PROPERLY done tri-wyes, go 1/2 way around the firing order, so that the pulses in the pairs of tubes which combine at the first wye are spaced evenly, 360 (crank) degrees apart: 1 & 6; 8 &5; 4 & 7; 3 & 2. As you can see, each pair takes one tube from each bank of the motor. Then, at the second wye, pair 1-6 with 4-7 and pair 8-5 with 3-2 so as to get evenly spaced pulses at the second wye in each header. If you wanna go with REALLY long tri-wye branches, (surprising how fantastically good this is for street, high torque, & 4x4 type apps.) start out with a regular set of 4 into one headers (of the smallest tube size you can find), cut them off a bit before the collectors, and do the snaking back and forth under the bell housing/tranny to get the correct first wye pairings. The second branches want to be the same length as the first ones, but there are no crossovers if you plan ahead. After the four second branches combine into two (tertiary) pipes, you want a length of pipe of length equal to all the first and second branches. At the end of that pipe, you need a gap (no diameter change of offset in the pipe) in the pipe about 3/4 inch long. Put an empty plenum chamber around that gap. The volume of the plenum needs to be maybe double the internal volume of the last (single) length of pipe feeding it. Just run a full size tail pipe and low restriction muffler behind the plenum (Not much vehicle length left after this, anyway!) The headers will effectively see the plenum as an open ended (to atmosphere) pipe. DO NOT omit the plenum, it is worth quite a bit of HP and response! For street stuff, usually, primary tubes 1 trade size SMALLER than the size which can be swedged square to fit into a flange and match the port properly work out to be the correct size. (If a 1-7/8" tube can be squared at one end and fitted into a flange so that the inside of that tube matches the port shape, then run the primary tubes with 1-3/4 " tubing.) You want the internal AREA of your primary tubes to be about equal to the cros-sectional AREA of the exhaust port. The above is what usually works out right. (Especially if the engine designer did his homework!) The extra work involved in getting down to the smaller tube size is why most off the shelf headers use too big a tube size! Figure the length of the primary tubes so that each of their internal volumes is about 140% of the displacement of an individual cylinder. (For instance, for a 350 cid V-8, using 1-3/4" tubes (which are about 1-5/8" inside diameter in 16 gauge tube, this would mean you want (at least) 24 inch long primary tubes.) (And if you are using lighter than 16 gauge tubing, don't bother!) If the primaries are 1-3/4", then 2" is usually about right for the secondaries, and 2-1/4" for the next ones. (A quarter inch increase in tube size at each successive wye is usually about right. 1-3/4" diameter primary tube size was only an example. It is prolly BIG for a street 350, 1-5/8" or 1-1/2" is more likely to be right (but with more tube length so as to get to the same internal tube volume!) If you build a set of tri-wyes this way, they will sound and run like nothing else! The throttle response will be astounding! But it is a ROYAL pain in the #@$% to do it! All my experience says that the biggest gain from headers is from giving as much of the exhaust gas as possible somewhere to go freely during the "blowdown" part of the exhaust stroke--before the piston starts back up significantly. Yes, it's nice to have a low pressure pulse in the exhaust port at overlap, and that pulse helps to scavenge clearance gasses if you have it there at the right time, but the longer you can keep the blowdown stage flow sonic, the less work the engine will have to waste pumping exhaust gas out of its cylinders, and the more sonic energy there will be available for creation of a scavenging pulse! Regards, Greg ------------------------------ From: "Walter Sherwin" Date: Thu, 7 Jan 1999 15:25:34 -0800 Subject: Re: Injector Duty Monitor > >DUTY CYCLE is calculated, by meters, as the percentage of time the >circuit is "asserted" between event triggers. This means that the >"period" is measured from injector opening to injector opening, or >injector closing to injector closing. The percentage of this period >occupied by the "asserted" mode, or injector energized, is read as DUTY >CYCLE. As such, there is NO requirement to know the firing mode of the >engine, or anything else. It WILL be accurate. >The DUTY RATIO is the ratio of time on vs time off and is generally not >used. This would be stated as 8:2, not 80%. Even with duty ratio, the >effect is the same - conversion is direct as long as the 2 numbers >(before and after colon) add up to 10. > >I fail to see how the injection mode can affect this. I agree with everything you have said, but ONLY when the entire period between event triggers can be used for the purpose of injection. What if a portion of the period between triggers is programmatically inhibited? Consider this example...... A sequentially injected, V8, at 5000 RPM, with say a 7ms commanded pulsewidth, and operating under the guidance of a control system which only permits injection to occur during a portion of the engine airflow cycle defined by 20 degrees BTDC through to 40 degrees ABDC. The period between consecutive "Start" triggers, for a given injector would be about 24ms (lets call this "Maximum" time). The period between the "Start" trigger and the target "End" trigger for that same injector would be about 8ms (lets call this "Ultimate" time). The real Duty Cycle of the injector would then be 7ms/8ms = 87.5%? On the otherhand, would your meter not interpret this as 7ms/24ms = 29%? You can also run into a similar problem with TBI fueling, if the system you are using can flip/flop from synchronous (event driven) delivery to asynchronous (time driven) delivery. If you don't agree then please let me know! You're in Ontario too? What part? Say "Hi" sometime, offline. Take Care; Walt. ------------------------------ From: bearbvd@xxx.net (Greg Hermann) Date: Thu, 7 Jan 1999 13:27:51 -0700 Subject: Re: Water Injection Thread [now U joints] ... you could also dig up and use an old Mopar ball&trunnion >joint, which will also handle more angularity than the saginaw or spicer, >plus it is a plunge joint, so it handles the slipyoke problem, too. Is this the proper name for the things I have inside the (closed type) steering knuckles of one of my Dana 70F steerable drive axles, which I have always heard called (usually affectionately) "Chinese Puzzle Joints"??? Or are they something else again?? Regards, Greg ------------------------------ From: "Bruce Plecan" Date: Thu, 7 Jan 1999 15:05:42 -0500 Subject: 128K vs 256K Proms in one ecm Could some one splan to me why if the 739+749 use the same PCB, why the 730 will not see a 128K prom, and a 749 sees either. 730 using AUJP 749 using syclone campaign chip On a 730 (92 Camaro), there is a 4th gear switch, that the ecm "uses", anyone know for what?, timing, fuel, TCC all seem the same wiether it's on or off. There is a difference in TCC pinouts from 749 to 730. The 730 basically leaves the EGR on all the time and flickers it once in a while to test, it. 749 seems to not even flicker it, strange. On the syclone idle if it's below 550 the IAC retracts, that's fine, but as it exceeds 575 goin to a desired 600 the 600 jumps to 1250 anyone played with this?? Seems like would be lousy idling. Bruce ------------------------------ From: Jemison Richard Date: Thu, 7 Jan 1999 15:56:02 -0500 Subject: RE: FI system opinion? Pricey! Rick > -----Original Message----- > From: Aaron Andrews [SMTP:aarona@xxx.net] > Sent: Thursday, January 07, 1999 2:31 PM > To: diy_efi@xxx.edu > Subject: FI system opinion? > > Just wanted to get anyone's opinion on the Racetech SDS FI System that is > a > complete programmable system > for $650, add $350 for a distributorless ignition and engine management > system? > > TIA > Aaron ------------------------------ From: "Clarence L.Snyder" Date: Thu, 07 Jan 1999 16:41:38 -0500 Subject: Re: Injector Duty Monitor Walter Sherwin wrote: > > > > >DUTY CYCLE is calculated, by meters, as the percentage of time the > >circuit is "asserted" between event triggers. This means that the > >"period" is measured from injector opening to injector opening, or > >injector closing to injector closing. The percentage of this period > >occupied by the "asserted" mode, or injector energized, is read as DUTY > >CYCLE. As such, there is NO requirement to know the firing mode of the > >engine, or anything else. It WILL be accurate. > >The DUTY RATIO is the ratio of time on vs time off and is generally not > >used. This would be stated as 8:2, not 80%. Even with duty ratio, the > >effect is the same - conversion is direct as long as the 2 numbers > >(before and after colon) add up to 10. > > > >I fail to see how the injection mode can affect this. > > I agree with everything you have said, but ONLY when the entire period > between event triggers can be used for the purpose of injection. What if a > portion of the period between triggers is programmatically inhibited? > > Consider this example...... A sequentially injected, V8, at 5000 RPM, with > say a 7ms commanded pulsewidth, and operating under the guidance of a > control system which only permits injection to occur during a portion of the > engine airflow cycle defined by 20 degrees BTDC through to 40 degrees ABDC. > > The period between consecutive "Start" triggers, for a given injector would > be about 24ms (lets call this "Maximum" time). The period between the > "Start" trigger and the target "End" trigger for that same injector would be > about 8ms (lets call this "Ultimate" time). The real Duty Cycle of the > injector would then be 7ms/8ms = 87.5%? On the otherhand, would your > meter not interpret this as 7ms/24ms = 29%? > > You can also run into a similar problem with TBI fueling, if the system you > are using can flip/flop from synchronous (event driven) delivery to > asynchronous (time driven) delivery. > > If you don't agree then please let me know! You're in Ontario too? What > part? Say "Hi" sometime, offline. > > Take Care; > Walt. From Waterloo Ontario - yes it would read as you state - but no problem. What we are trying to do is make sure the injector is not "locked on" or run in fire-hose mode. The "experts" say 80% is maximum, and in the scenario you propose, anything approaching 80% would be impossible. ------------------------------ From: dave.williams@xxx.us (Dave Williams) Date: Thu, 07 Jan 1999 08:50:00 -0500 Subject: Turbo header design - -> My question is: why can't this be applied to the header of a turbo'= - -> d engine: pre-turbo. I know that the turbine is already turning and - -> = therefor creating a vacuum; but, at velocities reaching .75 mach, - -> wou= ldn't any tuning, like using the 180 out exhaust arrangement - -> help?? = That's exactly how the factory exhaust on my Yamaha XJ650 Turbo is configured. It could be considered a long 180 collector or a short second branch tri-Y. The service manual says it smoothes the exhaust pulses to make the turbo slightly more responsive than a normal collector. ------------------------------ From: bearbvd@xxx.net (Greg Hermann) Date: Thu, 7 Jan 1999 15:14:22 -0700 Subject: Re: Injector Duty Monitor >> >>DUTY CYCLE is calculated, by meters, as the percentage of time the >>circuit is "asserted" between event triggers. This means that the >>"period" is measured from injector opening to injector opening, or >>injector closing to injector closing. The percentage of this period >>occupied by the "asserted" mode, or injector energized, is read as DUTY >>CYCLE. As such, there is NO requirement to know the firing mode of the >>engine, or anything else. It WILL be accurate. >>The DUTY RATIO is the ratio of time on vs time off and is generally not >>used. This would be stated as 8:2, not 80%. Even with duty ratio, the >>effect is the same - conversion is direct as long as the 2 numbers >>(before and after colon) add up to 10. >> >>I fail to see how the injection mode can affect this. > > > > > >I agree with everything you have said, but ONLY when the entire period >between event triggers can be used for the purpose of injection. What if a >portion of the period between triggers is programmatically inhibited? > >Consider this example...... A sequentially injected, V8, at 5000 RPM, with >say a 7ms commanded pulsewidth, and operating under the guidance of a >control system which only permits injection to occur during a portion of the >engine airflow cycle defined by 20 degrees BTDC through to 40 degrees ABDC. > >The period between consecutive "Start" triggers, for a given injector would >be about 24ms (lets call this "Maximum" time). The period between the >"Start" trigger and the target "End" trigger for that same injector would be >about 8ms (lets call this "Ultimate" time). The real Duty Cycle of the >injector would then be 7ms/8ms = 87.5%? On the otherhand, would your >meter not interpret this as 7ms/24ms = 29%? > >You can also run into a similar problem with TBI fueling, if the system you >are using can flip/flop from synchronous (event driven) delivery to >asynchronous (time driven) delivery. > >If you don't agree then please let me know! You're in Ontario too? What >part? Say "Hi" sometime, offline. > > >Take Care; >Walt. I disagree, Walt-- duty cycle is time on per event spacing, not time on per max time allowed by the program. It is only semantics, but time on per event spacing is what any normal meter will read, plus it is the definition of duty cycle which will relate directly to fuel used per unit time and thus directly to horsepower. Greg ------------------------------ From: "Ross Myers" Date: Thu, 7 Jan 1999 11:40:27 +1100 Subject: Re: Delco 639 >Have any of you guys come accross a DELCO 16208639??? >they have no memcal......same size as a 165/808 >They come out od the 94 Holden Barina 1.4 Auto > >Justin Wasn't the Barina a re-badged Suzuki or something?, if it is a re-badge it's probably using whatever Suzuki used in their equivilent, just with a Delco P/N. The Holden Calibra, it's says Holden, but it's full of Bosch electronics, not Delco. Regards Ross Myers ------------------------------ From: "Bruce Plecan" Date: Thu, 7 Jan 1999 17:41:20 -0500 Subject: Fw: 128K vs 256K Proms in one ecm Please ignore the 1250 idle comment Bruce - -----Original Message----- From: Bruce Plecan To: DIY_EFI Date: Thursday, January 07, 1999 4:13 PM Subject: 128K vs 256K Proms in one ecm >Could some one splan to me why if the 739+749 use the same >PCB, why the 730 will not see a 128K prom, and a 749 sees >either. >730 using AUJP 749 using syclone campaign chip > On a 730 (92 Camaro), there is a 4th gear switch, that the ecm >"uses", anyone know for what?, timing, fuel, TCC all seem the same >wiether it's on or off. > There is a difference in TCC pinouts from 749 to 730. >The 730 basically leaves the EGR on all the time and flickers it once >in a while to test, it. 749 seems to not even flicker it, strange. > >On the syclone idle if it's below 550 the IAC retracts, that's fine, >but as it exceeds 575 goin to a desired 600 the 600 jumps to 1250 >anyone played with this?? Seems like would be lousy idling. >Bruce > ------------------------------ From: "Aaron Andrews" Date: Thu, 7 Jan 1999 15:00:18 -0800 Subject: Re: FI system opinion? Do you know of a cheaper easier to use solution? - ----- Original Message ----- From: Jemison Richard To: Sent: Thursday, January 07, 1999 12:56 PM Subject: RE: FI system opinion? Pricey! Rick > -----Original Message----- > From: Aaron Andrews [SMTP:aarona@xxx.net] > Sent: Thursday, January 07, 1999 2:31 PM > To: diy_efi@xxx.edu > Subject: FI system opinion? > > Just wanted to get anyone's opinion on the Racetech SDS FI System that is > a > complete programmable system > for $650, add $350 for a distributorless ignition and engine management > system? > > TIA > Aaron ------------------------------ From: ECMnut@xxx.com Date: Thu, 7 Jan 1999 18:00:33 EST Subject: Re: Turbo header design In a message dated 1/7/99 5:19:29 PM Eastern Standard Time, dave.williams@xxx.us writes: > > That's exactly how the factory exhaust on my Yamaha XJ650 Turbo is > configured. It could be considered a long 180 collector or a short > second branch tri-Y. The service manual says it smoothes the exhaust > pulses to make the turbo slightly more responsive than a normal > collector. > How exactly is it? like two two-into-ones? Thanks, Mike V. ------------------------------ End of DIY_EFI Digest V4 #16 **************************** 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".