DIY_EFI Digest Saturday, 23 December 1995 Volume 00 : Number 011 In this issue: Carb vs Fuel Injection Haltech RE carb vs. FI Re: Carb vs Fuel Injection Re: General question Re: RE carb vs. FI Re: MGB RE: General question Re: MGB Re: RE carb vs. FI RE: General question RE: General question RE: RE carb vs. FI RE: General question See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Derrick Early Date: Fri, 22 Dec 95 8:10:45 "EST Subject: Carb vs Fuel Injection Ok, it looks like no one reads Hot Rod. In a previous post, I asked if anyone has read the issue of Hot Rod that had an article on Carburetion vs Fuel Injection. Since I have not received a reply, I must assume that either someone is too embarrassed to admit that they read Hot Rod or that no one reads it. I tried to find it down at the University, but they stopped their subscription in 1991 :(. The title is Carburetion vs. Fuel Injection in the October 1, 1994 issue of Hot Rod. The summary of the article is "the dyno doesn't lie." You can reply to me directly if you would prefer. I will keep your comments in confidence. Thank you all in advance. Yours, - -- Derrick Early early@xxx.mil ------------------------------ From: BCLEMEN@xxx.EDU Date: Fri, 22 Dec 95 08:11:16 EST Subject: Haltech I have been running an old Haltech F3 unit (fuel only) on a street driven, automatic, small block Camaro with a tunnel ram style intake for a couple of years now and it has been, in general, a good experience. Contacting reps for the company has been difficult at times but I saw they had a booth at the trade show in Columbus a couple of weeks ago so I guess they are still available. BYRON CLEMENS BITNET: BCLEMEN@xxx.BITNET HUMAN RESOURCES APP SPEC I INTERNET: BCLEMEN@xxx.EDU 100 ANTOINETTE, ASB #1, RM 156.1 PHONE: (313) 577-2059 Detroit, MI 48202 FAX: (313) 577-8767 ------------------------------ From: Steve Knickerbocker 512-356-3000 X6759 Date: Fri, 22 Dec 1995 08:30:00 -0600 (CST) Subject: RE carb vs. FI I think I may have read that article. Heck, I might even have it in my archive (read box in garage). If I remember right Hot Rod made some claim along the line of "FI is no better than a finely tuned carb". Maybe on a dyno but I really doubt it in the real world. Besides who wants to spend each weekend tuning a carb. How does a carb compensate for a cold front? Thunderstruck... ------------------------------ From: MTaylorfi@xxx.com Date: Fri, 22 Dec 1995 10:17:12 -0500 Subject: Re: Carb vs Fuel Injection Hey if you find out the info, please send me it. I gratuated from college in May and since renewed my Car Craft and PHR magazine subscription. I feel HOT ROD is pro-Chevy (at least 5 years ago). If I'm wrong please tell me. You can order older issues direct from the magizine publishers. See ya, Mike ------------------------------ From: walter@xxx.com (thomas walter x5955) Date: Fri, 22 Dec 95 09:17:32 CST Subject: Re: General question Orin, On a MGB witha 5 port head, biggest problem with fuel injection is timing the injection cycle. Since the intake ports a siamesed the injector needs to be on ONLY during the time when the intake valve is opened... the sysem would have to be a sequential mode, preferably timed to the closing of the intake valve. To have the injector big enough for WOT throttle may result in a poor idle. David Vizard went to great lenghts to get a Weber to deliver proper flow in his book on "How to modify your Mini". Book is long since OOP (out of Print), but highly recommended reading. Hmm... Peter Wales has been quiet, but hopefully can add some thoughts. (Most of the list is V8 people, who a 5 port head seems a little "different" ;-) Cheers, Tom Walter '67 Datsun 2000 '68 Datsun 2000 '71 & '72 Datsun 510's [hate this line edit mode... not on his Workstation] ------------------------------ From: Derrick Early Date: Fri, 22 Dec 95 11:35:18 "EST Subject: Re: RE carb vs. FI > > > I think I may have read that article. Heck, I might even have it > in my archive (read box in garage). If I remember right Hot Rod > made some claim along the line of "FI is no better than a finely > tuned carb". Maybe on a dyno but I really doubt it in the real > world. Besides who wants to spend each weekend tuning a carb. How > does a carb compensate for a cold front? > > Thunderstruck... > > Steve, Ok. Sounds like an article that I don't need to find. I guess their point is that it doesn't matter as long as the air to fuel is right. Thank you for digging into you memory banks. :) Yours, - -- Derrick Early early@xxx.mil ------------------------------ From: pjwales@xxx.net (Peter Wales) Date: Fri, 22 Dec 1995 17:03:55 -0500 Subject: Re: MGB I'm looking and listening. I'm not awfully familiar with the MGB head. Is 5 port = 2 siamesed inlets and 1 siamesed exhaust with 2 independant exhausts? Are we on twin carbs here? if so, then replace the carbs with injectors and use two injectors only like the Mitsubishi Starion system. In fact that may be a good system to adapt as it uses a Kharman (sp) vortex air meter off boost and a seperate ignition system. Just stick with the air meter and modify the bypass tubes to adjust the mixture close and then there is a mixture adjuster to fine tune it. Leave the electronics alone. If you want to make your own, then all you need to do is to fit cpu controlled mono to the injectors and cycle them. the injectors need to be sized to supply enough fuel for 2 cylinders at full power. The CPU would only provide environmental correction sucjh as battery voltage, water temperature etc and the mono would give fixed pulses when everything was "normal" The pulse rate would increase as the air flow increased. Then you could tune the CPU as other things needed doing.eg new cam. Just some ideas, try them on for size. If they don't fit, give me a hard time and I'll come up with more. Peter Wales President Superchips Inc Chairman Superchips Ltd "Timing is everything" ------------------------------ From: Jim Pearl Date: Fri, 22 Dec 1995 19:00:22 -0600 Subject: RE: General question Be careful with the Electromtive system! I looked at installing it = before I went with my DFI. The prices they quote usually don't include = wiring or software. The really expensive part is the software - I can't = believe the prices they charge. in order to do decent tuning you will = need to have the datalogging and if I were you I'd go whole hog and get = the Nitrous etc. stuff at the initial purchase. They are local to me and = I'm told they they're pretty good people - just make sure you're talking = about a whole package when you talk prices - the wiring isn't mentioned = (that I recall) in the literature and the software is rude unless you = intend to program multiple vehicles... P.S. I wish that DFI would do some of the innovative things Electromtive = has done. Most of the really neat stuff they do is mostly software stuff = (self programming type stuff etc.). Why can't DFI do some of this? - ---------- >From: Orin B. Harding[SMTP:orin@xxx.net] Sent: Thursday, December 21, 1995 10:14 PM To: diy_efi@xxx.edu Subject: Re: General question I'm also new to the list and have almost the same questions for the = others on the site. I have attempted to install a Bosch LU Jetronic system on a MGB ('79) = and found that while it would run OK when warm, I never could get it to = cold idle well. I finally have given up on this and am going to install = the Electromotive TEC II system. I talked to Haltec and I felt that they were not very, how should I say = it, "friendly"..A real turn off over the phone..They may have a great = system, but don't know how to deal with the public. Electromotive was = helpful and I really like the direct fire ignition feature included in = the TEC II for about the same cost as the Haltec F8. >Hi, > =20 >I just joined the list to see what you-all are talking about. I = scanned=20 >your Web site, and it looks like you're taking "Do It Yourself" very=20 >seriously--building systems from scratch. > ------------------------------ From: orin@xxx. Harding) Date: Fri, 22 Dec 1995 19:00:53 -0500 Subject: Re: MGB >I'm looking and listening. > >I'm not awfully familiar with the MGB head. Is 5 port = 2 siamesed inlets >and 1 siamesed exhaust with 2 independant exhausts? Yes, that's the arrangement; Intakes 1&2 siamesed and 3&4 siamesed..Exhaust #1 and #4 independent and #2&3 siamesed. > >Are we on twin carbs here? No this is a '79 which had one Zenith 175CD carb. I replaced the carb with the Ford throttle body, having made a base flange adaptor. The MGB intake/exhaust manifold was retained. The throttle body has one large injector and the one I used was for a 1.9L engine. I tried the 2.3L injector but it was much too big. > >if so, then replace the carbs with injectors and use two injectors only like >the Mitsubishi Starion system. What Mits. cars is/was this system used on??? The whole object here is to come up with an affordable EFI system for the MGB..The Electromotive system is in no way "affordable".. In fact that may be a good system to adapt as >it uses a Kharman (sp) vortex air meter off boost and a seperate ignition >system. Just stick with the air meter and modify the bypass tubes to adjust >the mixture close and then there is a mixture adjuster to fine tune it. >Leave the electronics alone. > > >If you want to make your own, then all you need to do is to fit cpu >controlled mono to the injectors and cycle them. the injectors need to be >sized to supply enough fuel for 2 cylinders at full power. The CPU would >only provide environmental correction sucjh as battery voltage, water >temperature etc and the mono would give fixed pulses when everything was >"normal" The pulse rate would increase as the air flow increased. Then you >could tune the CPU as other things needed doing.eg new cam. > >Just some ideas, try them on for size. If they don't fit, give me a hard >time and I'll come up with more. No, I will not be giving you a hard time!!!! I want to learn, so don't go away!! > > Orin Harding - Greensboro, NC ('74 MGB-GT - '79 MGB Roadster - '95 3000GT, BRG of course!) ------------------------------ From: jwharris@xxx. Harris) Date: Fri, 22 Dec 95 20:50 EST Subject: Re: RE carb vs. FI If I remember correctly, the article came to the conclusion that fuel injection produced a broader torque curve with less peak horsepower, the carb produced a higher peak H.P. - ---------------------------------------------------------------------------- J.W. Harris Delco Electronics Corp. Project Engineer One Corporate Center Powertrain Electronics M.S. CT40C Kokomo, IN 46904-9005 jwharris@xxx.com jwharris@xxx.com Of course, all responses are my own and should not be mistaken for those of Delco Electronics or General Motors. ------------------------------ From: orin@xxx. Harding) Date: Fri, 22 Dec 1995 21:25:12 -0500 Subject: RE: General question Jim, You're right about the Electromotive priceing policy...Hardware OK..Software TOOOOOO expensive for what you get...I also looked into the DFI/Accel/Mr. Gasket system and was shocked at how little information they send with their system. No wiring diagrams, pin-outs, nothing!!! The guy I talked to, at Accel, said I would have to make my own by tracing the wiring harness that came with the unit... Other than that, how do you like your system?? Orin Harding - Greensboro, NC ('74 MGB-GT - '79 MGB Roadster - '95 3000GT, BRG of course!) ------------------------------ From: fcmefi@xxx.net (Fred Miranda) Date: Fri, 22 Dec 1995 21:55:34 GMT Subject: RE: General question >Jim, > >You're right about the Electromotive priceing policy...Hardware OK..Software TOOOOOO expensive for what you get...I also looked into the DFI/Accel/Mr. Gasket system and was shocked at how little information they send with their system. No wiring diagrams, pin-outs, nothing!!! The guy I talked to, at Accel, said I would have to make my own by tracing the wiring harness that came with the unit... > >Other than that, how do you like your system?? >Orin Harding - Greensboro, NC >('74 MGB-GT - '79 MGB Roadster - '95 3000GT, BRG of course!) > Orin: With the MG I would recomend going with a sequential system, pref one with variable inj timing to help with fuel distribution. I wouldn't go with the Electomotive sequential as I don't think it is properly integrated into their standard system. ie you must use high impedence injectors. from what I remember the DFI sequential box is $2k or so, but no variable inj timing. I just got my Elan running on an Autronic SMC system. It's a very powerfull and well thought out system and costs about the same as a sequential TEC. Installation is a bit more involved though as there are 2 eng pos sensors, coil(S) and coil driver(S) to install. I used 2 Eclypse coils but it will drive 1-4 coil drivers. Another tool that might be really usefull on the "B" is the ability to vary inj flow from cyl to cyl varying amounts at different loads and rpm. Fred ------------------------------ From: Jim Pearl Date: Sat, 23 Dec 1995 02:04:32 -0600 Subject: RE: RE carb vs. FI Gee I guess that's what happens when you test a carb manifold against an = EFI manifold like say a TPI. I don't suppose they took that carburetor = manifold, drilled it for injectors, slapped an air door on it, and ran = the same tests with a tuned EFI system did they? I haven't seen the = article but I've heard some of the garbage from friends - "Put a carb on = it - it'll go faster". Many people don't realize that the torque curve = etc. isn't a function of how the fuel is delivered so much as it is the = manifold's tuning. I (IMHO) don't think the "cooling effect" of fuel = bouncing around a manifold has as much of an effect as having the fuel = in the right place at the right time in a good suspension. I'll step off my soapbox now (grin). I've seen a couple of these type = tests before in the Ford mags. irks me to no end. Jim '88 Ford Mustang Twin turbo 302 (DDMI\Spearco) - DFI - ---------- >From: J.W. Harris[SMTP:jwharris@xxx.com] Sent: Friday, December 22, 1995 7:50 PM To: diy_efi@xxx.edu Subject: Re: RE carb vs. FI If I remember correctly, the article came to the conclusion that fuel=20 injection produced a broader torque curve with less peak horsepower, the carb produced a higher peak H.P. - -------------------------------------------------------------------------= - --- J.W. Harris Delco Electronics Corp. Project Engineer One Corporate Center Powertrain Electronics M.S. CT40C Kokomo, IN 46904-9005 jwharris@xxx.com jwharris@xxx.com Of course, all responses are my own and should not be mistaken for those of Delco Electronics or General Motors. ------------------------------ From: Jim Pearl Date: Sat, 23 Dec 1995 02:29:14 -0600 Subject: RE: General question Tracing the harness? They will give you the pinouts for their computer - = I know I have a set (although I think it may be off a bit - mine's not = "standard"). I think what he may be trying to tell you is that he = doesn't have a standard plug in unit for your cars harness. The best way = around that is to run your own - I can say that 'cause I didn't have to = (smile). Others here can probably help you better with wiring than I = can. If the car you have started out carburated than I think (opinion = here) that the hardest part will be setting up the pickup from the = ignition. Keep in mind that the standard DFI is batch fire BTW and that = DFI isn't doing any development on it that I can find. As for liking it. Well I like it but I'm envious of the new system they = came out with for my car - a piggy back system (aargh!). With that = system you don't have to teach it to walk, crawl, jog, or get good gas = mileage. right now I'm tracking a mysterious O2 grounding problem (yeah = - - I've not even gotten under the car yet!). I also think the knock = sensor is too sensitive and would like to find out if the knock sensor = displays for the Buick GNs would work with my DFI's knock sensor to tell = me when that puppy sensed knock. I'd also like the ability to damp it = electronically. Some of the explanations for some of the idle screens = also aren't real clear. The person who wrote the software could use a = course in software design and it would be nice if I could track more = than 6 functions at a time with the datalogger. I'd also like it to log = more than once a second when doing extended logging. The book tries to = explain alot about the various screens - VERY little on how to tune the = system to work best - as in zero certain tables, get the fuel map right, = then tune the others. I guess you're supposed to goto one of their = dealers for that right? Duttweiler's fuel map that he thought would "get = me in the ballpark" had to be leaned over 50% (I'm not knocking him, I = just had a little trouble is all) and I killed many bugs driving to a = friend's house to get his laptop. Fooling with his off WOT timing curve = got me an extra 5MPG - up from 10 to 15 (still poor!). I could go on but you get the idea. The system works, the software could = be better, and I'm still learning. For the price you can't beat it = (IMHO) - mine was about $800 and plugged into my harness. I've read many = books on EFI (I posted about one earlier - it's very good) and = researched many options. I still get Electromotive's catalog every year = and think they're software sounds like nirvana - mind you I've not = programmed a car with it yet. DFI could do much of what they are doing = with their software but I guess they're mostly car guys and not software = guys.=20 When I look at friend's that are fueling their Vortechs with silly FMU's = and boost retards I just shake my head. I even know one guy who just = dropped a bigger than 460 big block in a car with a Vortech R-trim (ha - = it only makes 3lbs with his current pulleys) and is using the stock = EEC-IV computer (for a 302) with FMU and boost retard. Now tell me his = fuel and ignition curve is going to be anywhere close when he finally = hits 12lbs of boost? When compared to that sort of Mickey Mouse kind of = stuff I thank my DFI for at least letting me know what's going on and = retarding my timing when I'm too stupid to get out of it under = detonation. P.S. There is supposed to be some software for the DFI that allows you = to monitor much more than just 6 functions - but it won't let you = monitor O2 voltage. I'd love to find out where I can get it. Duttweiler = mentioned it to me.. P.P.S. - Sorry guys - I was on a roll and it got a little long! Would it = be of benefit if I posted some tech tips on what I've learned with my = DFI? I was actually hoping someone could tell ME this sort of stuff = (grin). - ---------- >From: Orin B. Harding[SMTP:orin@xxx.net] Sent: Friday, December 22, 1995 8:25 PM To: diy_efi@xxx.edu Subject: RE: General question Jim, You're right about the Electromotive priceing policy...Hardware = OK..Software TOOOOOO expensive for what you get...I also looked into the = DFI/Accel/Mr. Gasket system and was shocked at how little information = they send with their system. No wiring diagrams, pin-outs, nothing!!! = The guy I talked to, at Accel, said I would have to make my own by = tracing the wiring harness that came with the unit... Other than that, how do you like your system?? Orin Harding - Greensboro, NC ('74 MGB-GT - '79 MGB Roadster - '95 3000GT, BRG of course!) ------------------------------ End of DIY_EFI Digest V0 #11 **************************** 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".