DIY_EFI Digest Saturday, 27 July 1996 Volume 01 : Number 212 In this issue: Job Opportunities at Hypertech RE: Throttle Body Sizing RE: EFI control units RE: Throttle Body Sizing re: Re: water injection questions??? Alternate vacuum source re: Re: water injection questions??? Re: Job Opportunities at Hypertech Re: Job Opportunities at Hypertech [admin] volunteer needed Job Opportunities at Hypertech toothed wheels for crankshaft position sensing Re: toothed wheels for crankshaft position sensing Re: toothed wheels for crankshaft position sensing RE: Throttle Body Sizing Re: toothed wheels for crankshaft position sensing Re: toothed wheels for crankshaft position sensing Job Opportunities at Hypertech Bosch D-jetronic schematics? RE: Throttle Body Sizing RE: Throttle Body Sizing See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Jennifer Fraser Date: Fri, 26 Jul 1996 07:16:19 +0100 Subject: Job Opportunities at Hypertech Hypertech has two job positions open! Both positions require a strong C/C++ programming background. To avoid giving a lengthy description here, all interested can get the full details at our Web site. Our address is: http://www.hypertech-inc.com Respectfully, Jennifer Fraser Hypertech, Inc. R&D Engineer Web Master ------------------------------ From: "Orin Harding" Date: Fri, 26 Jul 96 13:24:35 UT Subject: RE: Throttle Body Sizing - ---------- From: owner-diy_efi@xxx.edu on behalf of Paul Shackleton Sent: Thursday, July 25, 1996 6:55 AM To: diy-EFI Subject: RE: Throttle Body Sizing >While trying to decide on the proper size throttle body for my MGB EFI >snip< >Here is what I think sizing should be based on. I've used my MGB's cam data >in this example: >1) Peak RPM: 6,000 >2) Engine CI Displacement: 110 >3) Intake valve duration (Deg): 252 >4) Time for 1 crank revolution: 0.01 sec. (60 sec / RPM) >5) Time for 1 deg. of crank rotation: 2.381E-05 (#4 / 360deg) >6) Intake time per 4 cycle period: .006 seconds (#5 x #3) >7) Intake time per minute: 21 seconds (#1 x #6) >8) Engine CFM requirement @xxx.8 CFM > ((#1 x #2) / 2) / 1728) >9) Estimated Throttle Body steady state flow requirement: 636 CFM > (60 sec./#7) x #8 >snip< What throttle bodies are you thinking of using? Are you making your own and if so, how? Or are you using proprietary ones? I am just about to start making some for the 2.0l 16v Vauxhall engine in my Westfield, but have yet to figure out how. Weber, Lumenition and Microdynamics throttle bodies seem to be very expensive. ie more than the equivalent sized carb without any of the complicated carb plumbing! I'm using a TB from a company called TWM located in CA (I'll send the address if you need it). They are kind of expensive and if I had it to do again I think I would go to a junk yard and get one off a VW Golf or something with an engine size of around 2.0L. Any ideas on DIY throttle bodies would be gratefully received? Also, in calculation #7, shouldn't #1 x #6 be 36 seconds? However 21 seconds is the answer if you say in two engine rotations (4 strokes) the inlet is open 252 degrees out of 720. Multiply this up to a minute (x60) and you get 21 seconds. I'm not sure whether the answer should be 21 or 36 though. 21 seconds is the correct time as the inlet (in my example) is open for 252 deg out of 720. ------------------------------ From: "Orin Harding" Date: Fri, 26 Jul 96 13:18:26 UT Subject: RE: EFI control units I'm quite new to the fuel injection scenario too. What is MAP verses MAF and what type does a SAAB have? MAP = Manifold Absolute Pressure MAF = Mass Air Flow I don't know what SAAB uses but most of the European cars use Bosch systems which typically use MAF. Thanks, John. Pioneers are the ones, face down in the mud, with arrows in their backs. Automation Artisans Inc. Ph. 604-544-4950 6468 Loganberry Place Fax 604-544-4954 Victoria BC CANADA V8Z 7E6 ------------------------------ From: "Orin Harding" Date: Fri, 26 Jul 96 13:15:33 UT Subject: RE: Throttle Body Sizing What is VE ? (Volumetric Efficiency) Thanks, John. Pioneers are the ones, face down in the mud, with arrows in their backs. Automation Artisans Inc. Ph. 604-544-4950 6468 Loganberry Place Fax 604-544-4954 Victoria BC CANADA V8Z 7E6 ------------------------------ From: SRavet@xxx.com Date: Fri, 26 Jul 96 10:49:23 CDT Subject: re: Re: water injection questions??? Dig Wrote: | There's also a company in the Northwest that makes a conversion kit | that allows re-routing of the A/C Freon to the liquid intercooler. 30 | degree output temps are claimed, but I'm not sure how much faith I have | in such a claim. It's an interesting approach, nonetheless. The AC evaporator is relatively small, why don't you just relocate it to the front of the engine and run your intake air thru it? - --steve Steve Ravet sravet@xxx.com Baby you're a genius when it comes to cooking up some chili sauce... ------------------------------ From: michael glidewell Date: Fri, 26 Jul 1996 12:07:50 -0400 Subject: Alternate vacuum source My 528i (1981) manifold vacuum is around 13 in Hg, reasaonbly steady, for an engine with 168k miles. I beleive the vacuum should be higher, based on Haynes manual, say around 16-22 inches. Question is, am I getting the full distributer advance with a less vacuum? I think not. Maybe a separate vacuum source which is controlled by the manifold vacuum could improve eng peformance. Anybody been tried this or have some thoughts on feasability? - ---------------------------------------------- Michael Glidewell Boston, Massachusetts glide@xxx.net KE1CP BMW 528i BMWCCA http://www.shore.net/~glide/ ------------------------------ From: Doug Rorem Date: Fri, 26 Jul 1996 11:19:11 -0500 Subject: re: Re: water injection questions??? >> Dig Wrote: >> >> | There's also a company in the Northwest that makes a conversion kit >> | that allows re-routing of the A/C Freon to the liquid intercooler. 30 >> | degree output temps are claimed, but I'm not sure how much faith I have >> | in such a claim. It's an interesting approach, nonetheless. >> >> The AC evaporator is relatively small, why don't you just relocate it to >> the front of the engine and run your intake air thru it? >> >> --steve >> >> Considering that an AC compressor can take 5 HP to run, do you really see an overall gain (HP wise) from this? - -- Doug Rorem University of Illinois at Chicago (312)-996-5439 [voice] EECS Department RM 1120 (312)-413-1065 [fax] 851 S. Morgan Street (708)-996-2226 [pager] Chicago, IL 60607-7053 rorem@xxx.edu ------------------------------ From: Jeffrey.Giberstein@xxx.EDU (Jeffrey Giberstein) Date: 26 Jul 96 12:35:59 EDT Subject: Re: Job Opportunities at Hypertech HI, Jennifer. Is Mike Walsh still working there? If so, how can I get in touch with him? thanks, Jeff Giberstein ------------------------------ From: Jeffrey.Giberstein@xxx.EDU (Jeffrey Giberstein) Date: 26 Jul 96 12:36:56 EDT Subject: Re: Job Opportunities at Hypertech whoops, ignore that. ------------------------------ From: Frank_Mallory@xxx.com (Frank Mallory) Date: Fri, 26 Jul 1996 11:45:15 -0400 Subject: [admin] volunteer needed d>There's that ugly word again... volunteer. d>I need someone, for about three months, to take over the day-to-day d>task of managing the mailing list request that for one reason or d>another don't get resolved automatically. d>The volunteer can easily do this maintenance remotely through d>email. Working knowledge of Majordomo would be helpful but not d>necessary. It's really just a job of unsubscribing mail that bounces d>and rerouting posts that get sent to the wrong address or that are too d>long. John, If nobody else steps forward, I'll be glad to help out. I don't know much about Majordomo, and I would have to work through the Fidonet gateway; but my e-mail has been pretty reliable and I check it every day. Frank Mallory ------------------------------ From: Jennifer Fraser Date: Fri, 26 Jul 1996 11:35:07 +0100 Subject: Job Opportunities at Hypertech Hypertech has two job positions open! Both positions require a strong C/C++ programming background. To avoid giving a lengthy description here, all interested can get the full details at our Web site. Our address is: http://www.hypertech-inc.com Respectfully, Jennifer Fraser Hypertech, Inc. R&D Engineer Web Master ------------------------------ From: Jeff Fisher Date: Fri, 26 Jul 1996 12:41:53 -0700 Subject: toothed wheels for crankshaft position sensing Does anyone know if Bosch or some other vendor supplies pre-fabed toothed wheels for crankshaft position sensing? If so, could you please point me to them. Thanks, Jeff ------------------------------ From: Jeffrey.Giberstein@xxx.EDU (Jeffrey Giberstein) Date: 26 Jul 96 16:27:37 EDT Subject: Re: toothed wheels for crankshaft position sensing I think that either Haltech or Electromotive supply these with some of their aftermarket kits, so either of those companies could probably help you out. Haltech 800-881-0117 Electromotive: 703-378-2444 ------------------------------ From: Markus Strobl Date: Fri, 26 Jul 1996 15:50:27 -0500 Subject: Re: toothed wheels for crankshaft position sensing > Does anyone know if Bosch or some other vendor supplies pre-fabed toothed > wheels for crankshaft position sensing? If so, could you please point me to > them. > > Thanks, > Jeff What kind of engine are you running? If the crankshaft you have is still in production for '96 you're in luck. With OBD-II most OEMs use crankshaft position sensors for the misfire detection. You could just get these pieces as spare parts. OBD-II came in '96. Markus ------------------------------ From: John Dammeyer Date: Fri, 26 Jul 96 14:31 PDT Subject: RE: Throttle Body Sizing At 01:15 PM 26/07/1996 UT, you wrote: > > >What is VE ? (Volumetric Efficiency) So, if I have this right, then as the piston moves to BDC on the intake stroke it results in a particular volume opening up; displacement of the individual cylinder. If this is, for example, 50cc, then 100% VE means that at BDC the pressure inside the cylinder is the same as atmospheric pressure? ie: 50cc of air/fuel has been drawn into the cylinder? Would lower values mean that there was still a slight vacuum in the cylinder? ie: VE% = pressure inside cylinder at BDC ------------------------------- * 100 atmospheric pressure Thanks for the info. John. Pioneers are the ones, face down in the mud, with arrows in their backs. Automation Artisans Inc. Ph. 604-544-4950 6468 Loganberry Place Fax 604-544-4954 Victoria BC CANADA V8Z 7E6 ------------------------------ From: scicior@xxx.com (Steve Ciciora) Date: Fri, 26 Jul 1996 15:10:40 -0600 Subject: Re: toothed wheels for crankshaft position sensing Thanks for the info. Electromotive got really grumpy, though when I asked if they sold individual components, like their 58 tooth wheel. "We are not inthe business of selling components. We just use them for our systems". The 800 # for Haltech didn't work, and 800-555-1212 didn't have a listing for them. Any pointers on where they are located (city,state) ? Thanks again! - -Steven Ciciora > I think that either Haltech or Electromotive supply these with some of their > aftermarket kits, so either of those companies could probably help you out. > > Haltech 800-881-0117 > Electromotive: 703-378-2444 > ------------------------------ From: Terry Faugno Date: Fri, 26 Jul 1996 15:26:05 -0700 Subject: Re: toothed wheels for crankshaft position sensing At 03:50 PM 7/26/96 -0500, you wrote: >What kind of engine are you running? If the crankshaft you have is >still in production for '96 you're in luck. With OBD-II most OEMs >use crankshaft position sensors for the misfire detection. You could >just get these pieces as spare parts. OBD-II came in '96. 1994, actually. I have a 95 (bought 6-1-94) Dodge Neon, and it uses a crank trigger mounted on the center counterweight. It's "psuedo-OBD-II" compliant. It measures more levels, as opposed to failures, than an OBD-I computer, but it's still able to be fooled. Terry ------------------------------ From: Jennifer Fraser Date: Fri, 26 Jul 1996 16:12:43 +0100 Subject: Job Opportunities at Hypertech Hypertech has two job positions open! Both positions require a strong C/C++ programming background. To avoid giving a lengthy description here, all interested can get the full details at our Web site. Our address is: http://www.hypertech-inc.com Respectfully, Jennifer Fraser Hypertech, Inc. R&D Engineer Web Master ------------------------------ From: Frank_Mallory@xxx.com (Frank Mallory) Date: Fri, 26 Jul 1996 11:22:48 -0400 Subject: Bosch D-jetronic schematics? > >Can anybody come up with a diagram for a d-jectronic brain used on a 72 >mercedes 280 sel 4.5? I just Inherited the thing and now that I own it, it's >gotta run right. It's down to 4-6 cylinders and hopefully a friend who >understands >electronics has said he might help figuire it out. Yes I know it's brain dead. I don't think you want to try modifying the circuitry in the brain box, or even repairing it. First thing is to check the plugs (not easy to get 'em out, but you'll get the hang of it after a few times). Chances are, you will find several that are not firing because they are fouled up. Put in new plugs and try to figure out while they are fouling up. It could be due to a the cold start system, or possibly because it is running too rich at idle or under load. The idle mixture can be adjusted at the brain box, and the total mixture can be adjusted at the pressure sensor (the grenade-shaped thing at the rear of the engine). If the plugs are not fouled up, but on the contrary look like they are running lean, it could be due to bad trigger points (bottom layer of the distributor) or a bad throttle switch. Again, you can adjust it to run richer; but these systems tend to go toward rich, not lean. Bottom line: don't mess with the brain box until you have checked out everything else. ------------------------------ From: Terry Faugno Date: Fri, 26 Jul 1996 15:49:04 -0700 Subject: RE: Throttle Body Sizing At 02:31 PM 7/26/96 PDT, you wrote: >At 01:15 PM 26/07/1996 UT, you wrote: >> >> >>What is VE ? (Volumetric Efficiency) > >So, if I have this right, then as the piston moves to BDC on the intake >stroke it results in a particular volume opening up; displacement of the >individual cylinder. If this is, for example, 50cc, then 100% VE means that >at BDC the pressure inside the cylinder is the same as atmospheric pressure? > >ie: 50cc of air/fuel has been drawn into the cylinder? > >Would lower values mean that there was still a slight vacuum in the >cylinder? ie: > >VE% = pressure inside cylinder at BDC > ------------------------------- * 100 > atmospheric pressure > As I was taught in college auto tech class, VE is this: actual fuel air mix in cylinder - ------------------------------- * 100 total possible fuel air mix For example, at the end of the intake stroke, in a 100CC total volume cylinder, if you have 75CC of fuel/air mix, then that is 75% volumetric effeciency. Some engines have their intakes tuned such that at certain RPM's, it resonates and can achieve better than 100% VE, like 105% or so. Typically NASCAR uses this technique. Terry ------------------------------ From: John Dammeyer Date: Fri, 26 Jul 96 21:09 PDT Subject: RE: Throttle Body Sizing At 03:49 PM 26/07/1996 -0700, you (Terry) wrote: > As I was taught in college auto tech class, VE is this: > >actual fuel air mix in cylinder >------------------------------- * 100 >total possible fuel air mix > >For example, at the end of the intake stroke, in a 100CC total volume >cylinder, if you have 75CC of fuel/air mix, then that is 75% volumetric >effeciency. Some engines have their intakes tuned such that at certain >RPM's, it resonates and can achieve better than 100% VE, like 105% or so. >Typically NASCAR uses this technique. > And of course the Turbo or Supercharger makes the VE% even bigger. By jove, I think I've got it. Thanks. John Pioneers are the ones, face down in the mud, with arrows in their backs. Automation Artisans Inc. Ph. 604-544-4950 6468 Loganberry Place Fax 604-544-4954 Victoria BC CANADA V8Z 7E6 ------------------------------ End of DIY_EFI Digest V1 #212 ***************************** 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".