DIY_EFI Digest Wednesday, October 27 1999 Volume 04 : Number 605 In this issue: EFI Conversions/Fuel Rails EFI COnversion Torque? Re: DIY_EFI Digest V4 #604 Re: DIY_EFI Digest V4 #604 EFI Conversion & Fuel Rails (pictures!) Converting a Performer manifold and TBI to TPI... See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Tue, 26 Oct 1999 16:00:36 -0400 From: Frederic Breitwieser Subject: EFI Conversions/Fuel Rails Howdy Ned, >questions though, How did you get the Injector >bungs lined up perfectyly?(or did you) the fab >guys over at holley seem to express this as >absolutly critical. Ahhh Grasshopper... that is the secret :) Actually, its not as difficult as it looks. Measure, measure, measure, then center punch the holes on the aluminum intake, then drill. When you install the injector bungs, make sure they are too long, then mill off the top and mill off the bottom on a different machine. Then magically, they are about the same height. The pictures are misleading, the injector bungs on my intake are 'damn close' to the same height, but slightly off. Since the inside of the bungs are machined to fit the body of the injector, a good part of the injector fits inside with the o-ring, so if they aren't exactly the same height, it makes little to no difference - there is enough "throat" in the bungs that the o-rings will make a good seal, even with 1/8" of positioning travel. Not bad, eh? I did the same on the fuel rail side, so I have the same amount of adjustment, though its only 1/16" of adjustment space since the injectors are shaped different on the tops of the injector body. >Also I am curious if you have any url's for >your fuel rails as I am have been pondering >my rail design Um, I just never took pictures of them, but I can do that. If I don't post a link in the next day or two, just remind me, I'll toss them on the coffee table and snap a few pictures. They are fairly simple. Instead of using a rectangular bar and boring that, I used round bar stock and machined injector top plates and welded them together. Entirely too much work. A rectangular bar would have been much easier. Frederic ------------------------------ Date: Tue, 26 Oct 1999 17:36:11 -0400 From: Frederic Breitwieser Subject: EFI COnversion Torque? > I had to think about this for a minute. > If you are converting a performer manifold designed to work wet, with a carb, to dry > PFI, will it still have the same torque characteristics?. Not sure who asked this, I find digest mode irritating. Anyway, if you convert a carb intake to TBI, you will experience the same fuel pooling issues for the most part because the fuel is still pre-runner. Minor difference might occur because EFI is more precise than a system affected by changes in motion (float bowl slosh, inertia on the valving, idle circuits, etc). For TPI, SFI & PFI, you'll find that you will make at least the same torque, if not a little more, because the runners are still the same length, diameter, etc, tuned for a specific RPM range for its max torque, however you have then added more precise fuel metering, so through a little fancy table editing, you can get a little more out of it. Masters of the Code obviously would do better than a monkey with a prom burner like myself :) ------------------------------ Date: Tue, 26 Oct 1999 19:41:02 -0400 From: rr Subject: Re: DIY_EFI Digest V4 #604 I like using a small red LED w/a 1k-ohm resistor. BobR. > Date: Fri, 22 Oct 1999 10:36:56 -0700 > From: lmaggi - Larry Maggio > Subject: Source for SES or Check engine light > > Im looking for a decent check engine light.... something a little more > aesthetically pleasing than your basic radio shack bulb. > > Any ideas? > > Thanks, > Larry > ------------------------------ Date: Tue, 26 Oct 1999 20:11:17 -0400 From: David Brode Subject: Re: DIY_EFI Digest V4 #604 Hello all, I said I was going to lurk, but I was very interested in the "long rambling message" posted today. I am a complete boob when it comes to electronics, but I want to ask a couple of questions anyway. 1. How many junkyard ecu options are there for a fangled port injected EFI system for a 511" twin turbo'd engine? [Sy/Ty only?] 2. Can two throttle bodies be used with one ecu? [I need around 1000 cfm] 3. If a fangled system is out for me, due to any reason, can the aftermarket Holley TBI systems be easily made to work with a blow through turbo deal? Fwiw - I don't see than much advantage to the wet manifold injection over blowing through a #4781 850 carb. Blast me if I need it. Dave Brode tt511" '67 Chev pickup ------------------------------ Date: Tue, 26 Oct 1999 17:32:05 -0400 From: Frederic Breitwieser Subject: EFI Conversion & Fuel Rails (pictures!) > Also I am curious if you have any url's for your fuel rails as I am have been > pondering my rail design > Ned Williams Howdy Ned, I don't recall whether you were on diyefi or gmecm, so both get it :) I updated the link, http://xephic.dynip.com/dodge/383intake.htm with the fuel rail pictures all the way at the bottom. Don't copy my design, while it works fine, it was ugly to make. I'd recommend rectangular bar stock so you have flat surface to rest on the milling table as well as for the injector body surface. Let me know what you think. - -- Frederic Breitwieser Xephic Technology 769 Sylvan Ave #9 Bridgeport CT 06606 Tele: (203) 372-2707 Fax: (603) 372-1147 Web: http://xephic.dynip.com/ ------------------------------ Date: Tue, 26 Oct 1999 21:54:22 -0700 From: Doug Dayson Subject: Converting a Performer manifold and TBI to TPI... I too was pondering this...I'd think that it really wouldn't matter if the carb manifold was operating wet flow or dry flow...VE and Cylinder Filling etc would be the same regardless...and the MPI will of course improve the fuel distribution... However...in talking with Arizona Speed and Marine they suggested that a single plane is better suited for a dry flow intake...even with a mild cam... I don't see why though (except that the individual runners flow rates are better matched in most single planes)...if it's a wet flow intake then the high rise dual plane would certainly perform better when cam timing is shorter...let's say 230 @xxx.050 and shorter hyd flat tappet in a 350 to 400 ci Chevy SB...if you then convert it to MPI the only change is the lack of fuel in the air stream...it seems that the highrise dual plane should still perform better at these milder engine speeds (below 6500)... What am I missing...I would think that this new Edlebrock Performer RPM Air Gap would be the best street manifold to convert to MPI for use with milder cams such as above...the power band is 1500 to 6500 or so for a 350ci...and the Air Gap design should help to cool the now dry air flow that is missing the cooling effects of the fuel...it should be even better if a heat reducing coating is added to it's bottom...and if it's used with a lifter valley shield... Shouldn't it? Am I missing something? Comments? Thanks...Doug > I had to think about this for a minute. > If you are converting a performer manifold designed to work wet, with a carb, to dry > PFI, will it still have the same torque characteristics?. > > Neil ------------------------------ End of DIY_EFI Digest V4 #605 ***************************** 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".