DIY_EFI Digest Friday, January 28 2000 Volume 05 : Number 041 In this issue: Correcting subject when replying Re: toyota o2 Re: basic tuning Peak and hold vs. Saturated injectors RE: J.C. Whitney AFR meter Re: J.C. Whitney AFR meter Re: Peak and hold vs. Saturated injectors Re: J.C. Whitney AFR meter Tech 1 Questions RE: J.C. Whitney AFR meter Re: Peak and hold vs. Saturated injectors 727+LT1Conectr.jpg RE: alky/water inj Re: DIY_EFI Digest V5 #40 See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Wed, 26 Jan 2000 20:00:16 +0000 From: Ade + Lamb Chop Subject: Correcting subject when replying Hi All, Just a quick request. Those of you who are still using the Digest could you make sure you change the subject line to from eg, Re: DIY_EFI Digest V5 #39 To the subject you are actually replying to please. Thanx, Ade - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 27 Jan 2000 09:39:44 -0800 From: garwillis@xxx.com (Garfield Willis) Subject: Re: toyota o2 On Wed, 26 Jan 2000 10:51:17 -0500 Scott_Hay@xxx.com >The Toyota sensor can in fact measure a broad range of a/f ratios but so far, >there is little information we have in the US as to how it actually works. Um guys, I've had a look at the pictures of this GReedy gizmo now, Bruce pointed me to: www.suprastore.com/supra/gredairfuelK.html but have a look Scott at that sensor, and see if it's the one you've been testing. I have a Toyota WB O2 sensor (cost me nearly $300 just for the sensor! argh), and it's definitely not the same animal as this one. Look carefully at the body shape and the probe tip openings. Judging from the description, I'd have to guess this is actually a conventional 4-wire heated sensor they've attempted to pull a calibration curve for, on the rich side. If so, it's AFR accuracy is gonna be pretty sloppy. >The sensor does have 4 wires, B+ for heater, ground for heater - controlled by >ecm (pwm), afr+ which supplies +3.3v from the ecm to one side of the sensor, and >afr- which the ecm supplies +3.0v to the other side of the sensor. > >We do see a variable voltage when using a scanner tool but when you measure the >sensor itself, voltage is not moving with major shifts in afr???? The general >thought is that it monitors the amperage and the direction of current flow to >determine the afr. The scan tool voltage is a calculated # to give diagnostic >functions. Yup, you're seeing there the behavior of all current-pump style sensors; you won't see much variation in Vs because there's a feedback loop in the interface that's intentionally attempting to hold Vs at a fixed value, while the current thru the pump is varied. It's the oxygen pump current that reflects the AFR, just as you surmise. In this case, it's the same two terminals +-afr, so the voltage across them is the Vs while the current thru them is the pump current. You've gotta be right about the scanner readout as well; that's AFTER the interface's pump current is read by the ECU and converted to AFR. >Very good and incredibly accurate sensor which operates in a linear fashion to >afr. > >This will probably add more questions than it answers but it is a start. If this is the sensor GReddy is using, at $285 for the complete system, it would indeed be a miracle deal. Doubtful, tho; check out the sensor. If someone can get a look at one of these, the Toyota part number should be right on the O2 sensor's metal outer jacket. Betcha a donut it's a conventional 4-wire heated sensor. :) Gar - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 27 Jan 2000 09:54:05 -0800 From: "Greg Moore" Subject: Re: basic tuning > At the FTP site > Tuning.doc > Grumpy If anyone else is looking for the file it's TuneTip1.doc It's a good start. Thanks Grumpy. Cheers, Greg - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 27 Jan 2000 14:32:07 -0800 (PST) From: Anthony Buccellato Subject: Peak and hold vs. Saturated injectors It's finally time to buy the injectors. Horsepower, boost, and RPM requirements (plus a bit of overhead) dictate 105 lbs/hr units. I believe these will be low impedance units. Does this correlate to peak and hold, or saturated style injectors? I'm using an electromotive driver, so low impedance isn't a problem. What I'm primarily concerned with is idle quality with the large injectors. I've heard that saturated style have a longer minimum pulse width, relative to peak and hold style. Anyone have info on this? Also, what is the best angle to weld the injector bosses into the manifold at? Within the mechanical limitations of a Chevy big block, should I be aiming as close to the back of the valve as possible? Are there any injector mfg's that do a better job than others at atomisation? I've located 160 lb/hr units, but would prefer to get closer to my actual requirements, so as not to compromise idle too badly. - - Clay - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 27 Jan 2000 14:59:25 -0800 From: "Randall" Subject: RE: J.C. Whitney AFR meter Rex Weatherford wrote : > > I was looking at the schematic for Dave's meter and had a few > questions. > > What is the LM3914? It's an integrated circuit made by National Semiconductor, designed to create a bar graph display with a minimum of external components. National's data sheet is at http://www.national.com/pf/LM/LM3914.html . The part should be available from most full-line electronics supply houses (which leaves out Radio Shaft). > > It says I can buy a meter like this from JC whitney for $20? Is that > true? Not quite. Current price is $36. See http://www.jcwhitney.com/product.jhtml?CATID=4571 . > > How are these used... I know that my ECM looks for values > between .100v > and 1.1v. And that my EGO sensor has to warm up before this means > anything. Correct? Basically. The LM3914 uses 1.2v as the reference (full scale), I assume the Whitney meter does the same. I believe the EGO sensor output is basically meaningless above about 0.9v. Randall - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 27 Jan 2000 18:16:28 -0500 From: "Bruce Plecan" Subject: Re: J.C. Whitney AFR meter May I suggest you check the achives about O2 sensor, and EGOR so at least you have a clue about what your doing here. While you might consider it's output over .9 as useless, I say below that is about as meaningful, in general the <$100 sensors are designed to function as a switch with the on/off point at 14.7:1 Grumpy | Rex Weatherford wrote : | > I was looking at the schematic for Dave's meter and had a few | > questions. > What is the LM3914? It's an integrated circuit made by National Semiconductor, designed to | create a bar graph display with a minimum of external components. | National's data sheet is at http://www.national.com/pf/LM/LM3914.html . The | part should be available from most full-line electronics supply houses | (which leaves out Radio Shaft). | > It says I can buy a meter like this from JC whitney for $20? Is that | > true? | Not quite. Current price is $36. See | http://www.jcwhitney.com/product.jhtml?CATID=4571 . | > How are these used... I know that my ECM looks for values | > between .100v | > and 1.1v. And that my EGO sensor has to warm up before this means | > anything. Correct? | Basically. The LM3914 uses 1.2v as the reference (full scale), I assume the | Whitney meter does the same. I believe the EGO sensor output is basically | meaningless above about 0.9v. | Randall - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 27 Jan 2000 18:23:25 -0500 From: "Bruce Plecan" Subject: Re: Peak and hold vs. Saturated injectors | It's finally time to buy the injectors. Horsepower, boost, and RPM | requirements (plus a bit of overhead) dictate 105 lbs/hr units. I believe | these will be low impedance units. Does this correlate to peak and hold, | or saturated style injectors? You are building a what?. 105 injectors?. To get anywhere near an idle would take P+Hs How big of motor is this?. | I'm using an electromotive driver, so low impedance isn't a problem. What | I'm primarily concerned with is idle quality with the large injectors. | I've heard that saturated style have a longer minimum pulse width, | relative to peak and hold style. Anyone have info on this? Yes, P+H, perfered cycling 1-5 msec, Sat 2-10msec. You can verify in the archives | Also, what is the best angle to weld the injector bosses into the manifold | at? Within the mechanical limitations of a Chevy big block, should I be | aiming as close to the back of the valve as possible? | | Are there any injector mfg's that do a better job than others at | atomisation? Yes, there is a day and night difference in flow rates from brand to brand, and style to style. Kinsler can plot things out for you. Sure, be nice if some folks would share their injector flow charts for time on vs pressure. I've located 160 lb/hr units, but would prefer to get closer | to my actual requirements, so as not to compromise idle too badly. 105-160?. BZZZZZTTTT, assuming you initial calilation is right the other is way off. Grumpy | | - Clay | | -------------------------------------------------------------------------- - -- | To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) | in the body of a message (not the subject) to majordomo@xxx.org | - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 27 Jan 2000 15:26:53 -0800 (PST) From: Orin Subject: Re: J.C. Whitney AFR meter > Basically. The LM3914 uses 1.2v as the reference (full scale), I assume the > Whitney meter does the same. I believe the EGO sensor output is basically > meaningless above about 0.9v. LM3914 doesn't need to do 0 to 1.2V, it's easy enough to set scale and limits using a couple of resistors per LM3914. I use two LM3914s and set the first to do 0 to 0.5 V and the second 0.5 to 1V, using just one of the 1.2V references. Orin. - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Fri, 28 Jan 2000 10:49:40 +1100 From: Richard Wakeling Subject: Tech 1 Questions Hi all, I am looking closer at the old "Tech 1" scan tool and have a few questions. 1) When "Tech 1" is connected to a VR commodore V8 is the cable that is used between "Tech 1" and ALDL the same cable (part number TA01299) that is used on the VN commodore but with an adaptor to suit the OBDII syle plug on the VR or do they use a different cable? 2) If a different cable is used for the VR commodore can someone give me the connections between the 15 pin D connector on the "Tech 1" and the 16 pin OBDII style plug. 3) Has anybody tried to reconstruct the circuit of the "Tech 1" or knows which pin of the 15 D pin plug uses the 8192 Data? 4) Does the "Tech 1" scan tool have various models depending on which country they are used in or is it just the Moduals for each vehicle that are different? The model of the "Tech 1" I am looking at here in Australia is 94-012 Thanks in advance Cheers Richard. - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 27 Jan 2000 18:19:25 -0700 From: bearbvd@xxx.net (Greg Hermann) Subject: RE: J.C. Whitney AFR meter > >Basically. The LM3914 uses 1.2v as the reference (full scale), I assume the >Whitney meter does the same. I believe the EGO sensor output is basically >meaningless above about 0.9v. > It is also basically meaningless if you are more than about 0.4 A/F ratio away from stoich! Greg - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 27 Jan 2000 18:27:26 -0700 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: Peak and hold vs. Saturated injectors >It's finally time to buy the injectors. Horsepower, boost, and RPM >requirements (plus a bit of overhead) dictate 105 lbs/hr units. I believe >these will be low impedance units. Does this correlate to peak and hold, >or saturated style injectors? > >I'm using an electromotive driver, so low impedance isn't a problem. What >I'm primarily concerned with is idle quality with the large injectors. >I've heard that saturated style have a longer minimum pulse width, >relative to peak and hold style. Anyone have info on this? > >Also, what is the best angle to weld the injector bosses into the manifold >at? Within the mechanical limitations of a Chevy big block, should I be >aiming as close to the back of the valve as possible? > >Are there any injector mfg's that do a better job than others at >atomisation? I've located 160 lb/hr units, but would prefer to get closer >to my actual requirements, so as not to compromise idle too badly. > >- Clay With an electromotive driver you will not have a snowball's chance where the sun don't shine of getting those injectors to idle. I believe that if you read the emotive literature (if they give you anything meaningful) that the minimum incremental change you can make to injector pw with their ecu is 64 us. I suggest that before spending ANY more money, you run some calculations, and figure out what minimum % change in AF ratio you would be making at idle!! (Even if the injectors would give repeatable flow at the very short pw you will need. Pretty revealing! Greg - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 27 Jan 2000 22:38:29 -0500 From: Shannen Durphey Subject: 727+LT1Conectr.jpg Help for separating the ecm from it's connector. Shannen - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 27 Jan 2000 23:36:21 -0600 From: Shawn B Subject: RE: alky/water inj Swiped from my Buick list was this lengthy post (minus the contact info) the goofy thing is that this was posted just today! start Subject: Water/alcohol injection I thought I would give my experiences with water/alcohol injection. First, lets clarify a few things. Water/alcohol injection is known in the aviation industry as "ADI" Anti Detonate Injection. I have been useing building ADI for many years on both aircraft engines and racing engines. I use to build 2,240 cid Rolls-Royce Griffon engines for unlimited hydroplanes. We use to run a factory liquid to air aftercooler AND liquid intercooler (the intercooler is a water jacket that surrounds the two stage superchager). But when the engine would backfire, it would sometimes rupture the aftercooler core. In a fresh water course, the added water induced into the intake system was OK, BUT in a salt water course.............salt water injection is NOT very good. So we decided to remove the aftercooler (besides, we were running out of aftercoolers seeing how the engines weren't produced after the late '40s) and increase the ADI quantity. In a 8 minute race we would consume 70 gallons of 115/145 AV gas with an additive in it, 25 gallons of 50/50 water/methanol, 130 lbs of nitrous oxide, and approx. 5 gals. of oil. We were running the engine at 4,200 RPM (calculate THAT piston velocity considering a 6.50" stroke and a 6.00" bore x 12) at 130 in/hg (in/hg is inches in mercury....approx 35+psi boost ..depending on atmospheric conditions) Detonation was and is always a problem at high boost levels. By removing the aftercooler we had more power due to increased airflow. We just replaced the aftercooler with a 6.00" inlet pipe from the superchager to the intake log/manifold. Back in 1989 I used ADI injection on my GN, and could use a Conley Mag4 race chip on 92 octane with no intercooler (I removed it to verify intercooler efficiency) and NO detonation. I have tuned a friends 87 T-Type to a 11.51 @ 117 on 92 octane pump gas, with a highly modified Jay Carter water/alcohol system. He was running 21-22 psi boost, ported heads, stock I/C, 2800 lock-up converter, DOT's, 202 cam, TE-44 turbo, with "blue tops", THDP, and through FOUR (4)mufflers. His car would run this with out doing ANYTHING to the car from the way it was run everyday on the street. ADI works by first reducing intake temps because of the latent heat value of the water and the alcohol. Methanol has 10 times the latent heat value of gasoline. And the steam that is created in the combustion chambers acts as a shock absorber to reduce tendencies to detonate. ADI has been around since the early thirties. ADI has even been used in early jet aircraft (707's and B-52's for example). ADI has to be understood to get the best results from it. It has to be tuned to your combination of parts and to the fuel curve of the system. On the street it can't be beat. At the track I would still recommend VP C-16 and a good intercooler because there are less things to cause problems. It does take a bit of tuning to accurately use ADI. Just think of it as ADI and NOT a power adder. It suppresses detonation. PERIOD. The friends T-Type used straight methanol and no water because the blue tops were too small for the car, so we used methanol as fuel enrichment AND ADI. stop Shawn GNandGS@xxx.com - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Fri, 28 Jan 2000 12:37:36 +1100 From: Andy Wyatt Subject: Re: DIY_EFI Digest V5 #40 Re Rex's Qs on the LM3914 the LM3914 is a chip manufactured by National Semiconductor. It is a dot/bar display driver chip - usually used to drive a ten segment LED bargraph. The 3914 is part of a family, and it specifically uses a linear scale. You can set the maximum and minimum voltages it will read (which correspond to LED1 and LED10) by applying voltages to external pins. You can also program either a dot (one LED only) or a bar graph (all LEDs from 1 to n, depending on voltage applied). You can hook one up the output of a standard O2 sensor which gives out the voltages you mentioned, and the chip also has a 1.25V reference built in, so you can program it to read 0 - 1.25V, which makes a pretty handy O2 display. There was a construction project done in Silicon Chip magazine, November 1995. I can give more details if required. Hope this is of some help Andy W :-D - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ End of DIY_EFI Digest V5 #41 **************************** 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".