DIY_EFI Digest Friday, 5 July 1996 Volume 01 : Number 190 In this issue: Re: Header insulation Re: 68HC11 Re: G-Force Measurement Re: 68HC11 header insulation Re: MAF output signal [none] See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Alexander.M.Lichstein@xxx. Lichstein) Date: 04 Jul 96 07:02:21 EDT Subject: Re: Header insulation That headr wrap stuff will likely retain heat TOO WELL. We have run with that stuff on, and can actualy touch the headers just after some time on the track. You may want to experiment with wrapping it part way down, and extending it or scraping some off as necessary. Be careful you don't heat up the system too much... cracked heads won't make that gas mileage seem so important. - - Z ------------------------------ From: Sandy Date: Thu, 04 Jul 1996 07:42:37 -0700 Subject: Re: 68HC11 At 09:50 AM 7/4/96 +0200, you wrote: >Does anyone have a program for an ECU on a HC11 (I prefer Assembler)? > > Their was one for a Direct Ignition System. I think it can be found on the EFI332 home page. ------------------------------ From: Chris Howard Date: Fri, 05 Jul 1996 02:12:34 +1000 Subject: Re: G-Force Measurement At 23:50 2/07/96 EDT, you wrote: >Hi to all, >I have been lurking on this list for quite awhile. Although a G-meter is not >strictly diy efi material, I know that many in the group may have an interest or >information regarding my inquiry. > >TO the point, I wish to either purchase or design an instrument for measuring >the G-forces generated during cornering of a vehicle. If anyone knows of a unit >made for this purpose, please reply and let me know. > >If I have to make one, maybe the adxl05 from Analog Devices would be the most >suitable place to start, however I have not yet managed to get a hold of a >databook/spec sheet. What does anybody else think? > I have used an accelerometer from IC Sensors in a datalogging application. The model is a 3028-002. It measures from +/- 2.2 g. Each unit comes with a circuit for temperature compensation and linearisation which reduces the error to around 0.5% from 0 to 1khz 0-50 degrees C. They are single axis and fairly pricey I think. The sales rep gave me three free samples so I never found out what the price was. :) I can give you more info, circuit diagrams etc. if you require. Chris Howard Computer Science University of New South Wales email: s2184002@xxx.au Web: http://www.usyd.edu.au/~choward ------------------------------ From: pfenske@xxx.ca (peter paul fenske) Date: Thu, 04 Jul 1996 08:46:43 -0700 Subject: Re: 68HC11 >Does anyone have a program for an ECU on a HC11 (I prefer Assembler)? > >> Hi Walt >>Wrote up a proto HC11 fuel controller using a EVB some >>years ago. I will share this one if you want. >>Let me know if you want it. I only have the original text >>or s19 files. >>Good Luck: peter pfenske@xxx.ca > > ------------------------------ From: Jim Steck <72614.557@xxx.COM> Date: 04 Jul 96 13:17:21 EDT Subject: header insulation >> I'd like too insulate my exhaust header down to the O2 sensor so it won't cool off and get better gas mileage( that's my theory anyway) Does anyone have a simple recommendation for something effective? I've thought of the asbestos muffler wrap stuff but I don't think it will retain the heat in very well. This for an 81 528i BMW. << Don't wrap any carbon steel exhaust pipe or you'll end up replacing it much sooner than you planned. Besides the higher temperature, the wrap traps moisture when the car is not running. I suggest one of the ceramic coatings like Jet-Hot. It does a fair job of insulating and keeps the pipe from corroding. - -Jim Steck AutoComponenti BTW, it does make a couple extra horsepower on the dyno with a tuned open exhaust (ask Smokey about the theory) . . . but I don't know about a system with a CAT and mufflers. ------------------------------ From: Stuart Baly Date: Fri, 5 Jul 96 11:36:25 EST Subject: Re: MAF output signal >From: mjos@xxx.com (mjos) >I am working on a frequency limiting circuit that will intercept the output >of my MAF sensor and pass the original freq as long as it falls at or >below a set limit. If it goes above the limit freq, the circuit will pass only >the limit freq. regardless of how high the input freq. goes beyond it. >Has anyone else made such a circuit? I am open to various ideas. Here's my two cents worth: Use a 4046 PLL as a F/V converter, then use a zener or similar to limit the voltage output. Then use the VCO from another 4046 to convert back to a frequency output. If you use well-matched components on both 4046's, the input and output frequencies should agree fairly well, until the input frequency rises above the point where the zener conducts, then the output will stay constant for all input frequencies above that. There might be other problems, for example 4046's can't output 0Hz without some changes to the surrounding circuitry, but this would have to be cheaper than a bought unit. I haven't built this, so there's a fair chance I'm talking rubbish. Stuart ========================================================= Stuart Baly (S.Baly@xxx.au) '71 Datrat 1600, '89 Kawasaki GPz900R, '81 Yamaha RD350LC ========================================================= ------------------------------ From: Todd King Date: Thu, 04 Jul 96 21:22:00 PDT Subject: [none] <<< From: arthurok@xxx.com (ARTHUR OKUN) Date: Thu, 4 Jul 1996 00:48:14 -0700 Subject: Re: MAF output signal >What is the typical freq. output range vs. air flow for these sensors. >>> Art I have a Buick GN; the MAF sensor is spec'd to go about 32Hz to 150Hz. The signal is a square wave. As part of a data aqu. project using a 6811 I was reading the freq of the MAF. A peak airflow value of 255 gram/sec corresponded to about 140 Hz. The gram/sec reading was output from the ECM as part of it's diagnostic data stream. Todd Todd_King@xxx.com ------------------------------ End of DIY_EFI Digest V1 #190 ***************************** 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".