DIY_EFI Digest Thursday, 3 July 1997 Volume 02 : Number 224 In this issue: A question on EFI theory Re: Fuel line, fittings Re: A question on EFI theory Re: Buick GNs Re: Buick GNs Speedo See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Mark Eidson Date: Wed, 02 Jul 97 05:52:00 PDT Subject: A question on EFI theory Text item: If one were to design a system from scratch and have complete control over fuel maps, etc., could a system be made that measured the MAP between the throttle body and supercharger rather than at the intake manifold? Could the fuel map be designed to compensate for the increased volumetric efficency of the supercharger at a given RPM and MAP? Putting it another way could I use my Holley 4di throttle body on a Whipple supercharger on a small block chevy with the MAP and vacuum taken off the throttle body port rather than the intake manifold? Thanks, me. Text item: External Message Header The following mail header is for administrative use and may be ignored unless there are problems. ***IF THERE ARE PROBLEMS SAVE THESE HEADERS***. Reply-To: diy_efi@xxx.edu Precedence: bulk Sender: owner-diy_efi@xxx.edu Content-Type: TEXT/PLAIN; charset=US-ASCII Mime-Version: 1.0 Message-Id: Subject: TPI and Jags That Run To: DIY_EFI@xxx.edu X-Sender: jhaag@xxx.edu From: John Haag Date: Tue, 1 Jul 1997 15:47:16 -0600 (MDT) Received: by odin.cair.du.edu; id AA27138; Tue, 1 Jul 1997 15:47:16 -0600 Received: from odin.cair.du.edu by coulomb.eng.ohio-state.edu via SMTP (940816.S GI.8.6.9/940406.SGI) for id RAA25526; Tue, 1 Jul 1997 17:47 :20 -0400 Received: by coulomb.eng.ohio-state.edu (940816.SGI.8.6.9/940406.SGI) for diy_efi-outgoing id VAA25531; Tue, 1 Jul 1997 21:47:24 GMT Received: from coulomb.eng.ohio-state.edu by thalia.fm.intel.com (8.8.4/10.0i); Tue, 1 Jul 1997 22:45:29 GMT Received: from thalia.fm.intel.com (thalia.fm.intel.com [132.233.247.11]) by chm ail.ch.intel.com (8.8.5/8.7.3) with ESMTP id PAA13048 for ; Tue, 1 Jul 1997 15:40:33 -0700 (PDT) Return-Path: owner-diy_efi-outgoing@xxx.edu ------------------------------ From: Alex Date: Wed, 02 Jul 1997 23:08:26 +1000 Subject: Re: Fuel line, fittings Stuart Baly wrote: > > I've just got myself the injection hardware off an import L18 Nissan > engine, with a view to fitting it to my Datsun 1600. At the moment, > I'm getting the parts together for the fuel supply. My problem is > that the supply and return lines to the fuel rail were cut, so they > haven't got those nice little flared collars near the ends to clamp > the fuel hose over. > Is there a special tool that can form these collars, perhaps a brake > line flaring tool, or is there another way? > Also, in a similar vein, intake pipework on a turbo engine is under > pressure. When making this pipework from stainless tube, how are the > ends formed to give the connecting hoses a secure grip? > =========================================== > Stuart Baly (s.baly@xxx.au) > Technical Officer > Cape Grim Baseline Air Pollution Station > Cape Grim, Tasmania, Australia > =========================================== Hello Stuart regards the pressure in the intake plumbing on your new EFI motor, remember that the turbo is pumping at less pressure (?~8 10lbs?)than what is found present inside your engines cooling system (~13-15lbs). Use good hose clamps and tighten them sensibly firm. You could also use a light powered glue if your really worried (ie Aussie Grip from Repco or Burson Auto parts. re your cut fuel rail, just go to the wreckers and cut some off another car, take them to a welders and have them brazed on to your new rails. Simple. Regards and Oh! I bet your 1600 has got plenty of bog in its rear quarters :-) Alex ------------------------------ From: "Mark Boggs" Date: Wed, 2 Jul 1997 10:45:09 -0400 Subject: Re: A question on EFI theory >If one were to design a system from scratch and have complete control over fuel maps, etc., could a system be made that measured the MAP between the throttle body and supercharger rather than at the intake manifold? digressing from your question, a bit... If I had the ability to design from scratch, I would go with something like the "new" FP Performance product that has a wide range O2 sensor and a very quick computer. I'm pretty sure that they also have to use some sort of MAF to measure incoming air flow, too. Being able to run in closed loop at WOT would be the best, I would think. Could this type of system eliminate the need for MAP or is it still necessary to help determine engine load? ------------------------------ From: Thomas Wright Date: Wed, 02 Jul 1997 11:43:22 -0400 Subject: Re: Buick GNs Corey L. Cole wrote: > Thomas Wright wrote: > > Are you saying that the GN system is the same as other buick 6cyl FI > > > systems of the same time period with just a different EPROM?I don't > know > > much about different GM systems and the years and models during > which > > things changed. I just know a little about TPI systems since there > is so > > much on the web and in catalogs for those things. I have also seen > > numerous sites on Buick turbos, but figured it was a special system > for > > GN. > > Is the MAF different between GNs and non turbo buicks? Do non turbo > > > buicks have the distributorless ignitions? > > I am interested in something REALLY common, so that I can get it > from > > the local junkyard CHEAP! > > Any information or source of information on different GM systems > > including models and the years of changes on common cars would be > > extremely helpful. > > Thanks > > Tom > > Yes, it's true. The ECM (or PCM :) is the same between turbo and > non-turbo > cars. The non-turbo cars also had the distributorless ignition like > the > GN. I'm not sure about the MAF as to whether or not it's the same > part > on turbo vs. non-turbo. > > Your best bet is to zoom over to the Buick Grand National web page: > http://www.gnttype.org/gnttype/www/ > > I believe there's some parts interchange information there, and you > can search > the archives as well. It's something that's been pretty well hashed > over > several times. > > Good luck, > -- > == > =========================================================================== > > 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. > ======================================================= > ====================== Hey, Thanks alot for the info! After doing a little research, it seems like this is definitely THE system. Distrubutorless ignition and everything! And finding a regular old 86-87 Buick 3.8 V6 in the junkyard should be easy and cheap. It seems that this system would probably work on my car with my old injectors (plus resister pack) and everything. And there definitely are enough high performance parts out there to expand the system way beyond what I'll ever need. The only tricky parts are the cam AND crank sensors (no such things on my engine, of course.) I have an old distributor that I can modify. But based on what I have read at the various sights I've visited, I am kind of confused. What type of signals do these sensors put out? The consensus seems to be that they are hall effect sensors, but the camshaft sensor is a solid disk with a slot cut in it that the sensor reads. What sort of "hall effect" sensor is this? It sounds more like some sort of optical pickup (you will have to excuse me, but my knowledge of electronic theory is limited to a physics class that was more oriented towards civil engineering. And that was a long time ago!) I am trying to figure out how I am going to duplicate these signals. Are all "magnetic pickups" the same as "hall effect", or are "hall effect" sensors just one type of magnetic pickup or vice versa? Sorry for the stupid questions, Tom ------------------------------ From: Michael J Weber Date: Wed, 02 Jul 1997 13:15:42 -0500 Subject: Re: Buick GNs > > Hey, >Thanks alot for the info! After doing a little research, it seems like >this is definitely THE system. Distrubutorless ignition and everything! >And finding a regular old 86-87 Buick 3.8 V6 in the junkyard should be >easy and cheap. It seems that this system would probably work on my car >with my old injectors (plus resister pack) and everything. And there >definitely are enough high performance parts out there to expand the >system way beyond what I'll ever need. >The only tricky parts are the cam AND crank sensors (no such things on >my engine, of course.) I have an old distributor that I can modify. >But based on what I have read at the various sights I've visited, I am >kind of confused. What type of signals do these sensors put out? The >consensus seems to be that they are hall effect sensors, but the >camshaft sensor is a solid disk with a slot cut in it that the sensor >reads. What sort of "hall effect" sensor is this? It sounds more like >some sort of optical pickup (you will have to excuse me, but my >knowledge of electronic theory is limited to a physics class that was >more oriented towards civil engineering. And that was a long time >ago!) I am trying to figure out how I am going to duplicate these >signals. Are all "magnetic pickups" the same as "hall effect", or are >"hall effect" sensors just one type of magnetic pickup or vice versa? >Sorry for the stupid questions, >Tom The cam sensor is a hall effect which stays high (above 7.5 Volts) until 25 degrees ATDC of the #1 cylinder. This is used to time the firing of the injectors only it doesn't have anything to do with spark timing. The crank sensor uses a ring with three tabs. Each tab is used to fire two spark plugs, since it is a waste spark system with three coils for six plugs. I don't know how big the tabs are on the crank damper but you can probably get one that would work from a junkyard. Michael J Weber mweber@xxx.com ------------------------------ From: Jennifer Rose Date: Wed, 2 Jul 1997 20:06:26 -0700 (PDT) Subject: Speedo Hi George Speedo is from America Science & Surplus - part number 26134 for $3.75 each. Phone number is 847-982-0870. They have a $10 min order - had to order three. Just got mine today - the're electronic\mechanical face, have odometer, trip. No lit with them, but with just three wire this shouldn't be hard. Still looking for sending unit to fit transfer case. Will visit wrecking to see if Peters hint about j-car will work. My tpi unit needs two pulse per rev. Could fab a divide by two to use newer sending unit. BTW old speedo is very noisy in pu. Vance ------------------------------ End of DIY_EFI Digest V2 #224 ***************************** 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".