DIY_EFI Digest Thursday, 28 March 1996 Volume 01 : Number 089 In this issue: Re: Injectors Re: Multi Spark Ignition... Re: unusbscribe Re: Multi Spark Ignition... Re: GM serial line communications Re: Multi Spark Ignition... Re: Multi Spark Ignition... Re: Multi Spark Ignition... Re: Multi Spark Ignition... re:4.3 multi-port fuel injection re: 96 Chevy 454 re: TPI info Re: injector pulse width attachment questions Off topic, but related subject matter... Re: injector pulse width Re: EFI for Bosch mech. injection VW Bosch injection Re: Off topic, but related subject matter... RE: Off topic, but related subject matter... Re: Off topic, but related subject matter... Re: Off topic, but related subject matter... The EFI project status Re: Off topic, but related subject matter... Re: Off topic, but related subject matter... Re: Multi Spark Ignition... See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Frank Parker Date: Wed, 27 Mar 1996 07:36:51 -0500 (EST) Subject: Re: Injectors > > and the pulse widths are down in the 3-6 ms range. The strange thing about > > the > > injector is that the nozzle is plastic with a large (approximately .080" > > diameter) straight orifice, and squirts a collinear stream, not a spray... > > > > I've considered reworking the orifice to reduce flow/generate a conical > > spray. > > > > Anyone have any suggestions? At the 10 psi you mentioned, you will get a stream. Most injectors I have tested need at least 30 ps i to generate a conical spray. Frank > ------------------------------ From: Frank Parker Date: Wed, 27 Mar 1996 07:44:01 -0500 (EST) Subject: Re: Multi Spark Ignition... On Tue, 26 Mar 1996, Michael F. Sargent wrote: > That's a Multiple Spark Discharge unit you probably saw. They are commercially > available from MSD and available at any speed shop. Since they sell for just > over $100, I wouldn't bother building one. > > > As for 40% increase in power ... bull****. Someone is really putting you on. > Either that or that S10 must have been just barely running. > You should also realize that the multiple spark last for about 20 deg of engine rotation. Once you get past about 2500 rpm , it is a single spark system. If your stock ignition is functioning properly, a MSD or similar normally will yield just a few hp. Helps best on idle, loading up, etc.. Frank > +--------------------------------------------------------------------------+ > > ------------------------------ From: ampike@xxx.net (Andrew Pike) Date: Wed, 27 Mar 96 06:17:31 MST Subject: Re: unusbscribe unusbscribe DIY_EFI ampike@xxx.com ------------------------------ From: Bruce Bowling Date: Wed, 27 Mar 1996 9:52:08 EST Subject: Re: Multi Spark Ignition... ~ ~ Jim, ~ What most people don't realise with the MSD is that (on a V8) over ~ about 4000 RPM, maybe less I can't remember the actual RPM, the MSD becomes ~ a "normal" single fire CDI. ~ ~ regards, ~ Mark Boxsell ~ MRB Design. ~ ~ Since the MultiSpark issue has been brought up, *someone* in the past had reversed-engineered the box and was going to post the schematic??? Also, does anyone know what Autotronics states is the number of sparks per cylinder event at idle? John told me he gets something like 3 sparks at idle - I think that their (Autotronics) advertisements were something like 10 or 20. - - Bruce - -- - ----------------------------------------------------- <<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> - ----------------------------------------------------- Bruce A. Bowling Staff Scientist - Instrumentation and Controls The Continuous Electron Beam Accelerator Facility 12000 Jefferson Ave - Newport News, VA 23602 (804) 249-7240 bowling@xxx.gov http://devserve.cebaf.gov/~bowling - ----------------------------------------------------- <<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> - ----------------------------------------------------- ------------------------------ From: John S Gwynne Date: Wed, 27 Mar 96 12:38:20 -0500 Subject: Re: GM serial line communications - -------- In message <9602258278.AA827815632@xxx.ca> , you write: | At the end of January there was some interest in reading the 8000 baud GM ser | ial | or some of the source code I can forward the information to them. Perhaps th | ere | is a place that I can post this in the DIY EFI archives. | | Will McGonegal | wmcgonegal@xxx.ca Files can currently be placed on coulomb for retrieval via email. Our WWW sites (DIY_EFI and EFI332) are [probably] also available. I now have a working computer that will serve as a more permanent ftp site for the group, but I still have to find an Ethernet drop. Soon.... John S Gwynne Gwynne.1@xxx.edu _______________________________________________________________________________ T h e O h i o - S t a t e U n i v e r s i t y ElectroScience Laboratory, 1320 Kinnear Road, Columbus, Ohio 43212, USA Telephone: (614) 292-7981 * Fax: (614) 292-7297 - ------------------------------------------------------------------------------- ------------------------------ From: Frank Parker Date: Wed, 27 Mar 1996 14:08:59 -0500 (EST) Subject: Re: Multi Spark Ignition... > Since the MultiSpark issue has been brought up, *someone* in the past had > reversed-engineered the box and was going to post the schematic??? > > Also, does anyone know what Autotronics states is the number of sparks > per cylinder event at idle? John told me he gets something like 3 sparks > at idle - I think that their (Autotronics) advertisements were > something like 10 or 20. > > - Bruce > ----------------------------------------------------- The MSD box fires for 20 deg of engine rotation and converts to single spark @xxx. I have schmatic of MSD box which MSD sent to me years ago when I was doing the electrics on all the Roush Mustang and Capri Trans-Am race cars.( 21 cars built in 24 mo) Send me a email if you are interested. Newer six series boxes appear the same. Frank Parker> ------------------------------ From: ehernan3@xxx.com (Edward Hernandez (R)) Date: Wed, 27 Mar 1996 16:34:31 +0500 Subject: Re: Multi Spark Ignition... >I saw one of them(multi-spark units) a few days ago on an S10 chevy, >it picked up it's power 40% according to the engine dyno!!!! I really doubt that kind of improvement from an engine from a relatively modern vehicle. What year? What engine? And most importantly, what was the base ignition system that was costing them 40% power? I assume this is peak power. What about torque readings across the rest of the rpm range? What kind of condition was the rest of the engine in? I changed plug wires and picked up more than that, but my wires were in really old and in bad shape(I'm a cheapskate, see? Also a skeptic:) ------------------------------ From: ehernan3@xxx.com (Edward Hernandez (R)) Date: Wed, 27 Mar 1996 16:37:39 +0500 Subject: Re: Multi Spark Ignition... >That's a Multiple Spark Discharge unit you probably saw. They are >commercially available from MSD and available at any speed shop. MSD ignitions stop multiple sparks at around 3000rpm, which is why they have no effect at peak power. It's nice to know they cleaned up your idle and subsequent transients. ------------------------------ From: dave.williams@xxx.us (Dave Williams) Date: Wed, 27 Mar 1996 08:11:00 +0000 Subject: Re: Multi Spark Ignition... - -> What most people don't realise with the MSD is that (on a V8) over - -> about 4000 RPM, maybe less I can't remember the actual RPM, the MSD - -> becomes a "normal" single fire CDI. MSD tells you that up front. Though for some reason people tend to get all excited about it, it's no secret, and there's no real advantage to multiple sparks over three or four thousand RPM, which is pretty hard to do with a stock-type coil feeding eight cylinders. It takes time to charge and discharge the coil, you know. You could go to a specially wound coil, but since there's little advantage at high RPM anyway, that's the province of expensive racing "engine management systems", not $125 CDI controllers. ====dave.williams@xxx.us========================DoD#978======= can you help me...help me get out of this place?...slow sedation... ain't my style, ain't my pace...giving me a number...NINE, SEVEN, EIGHT ==5.0 RX7 -> Tyrannosaurus RX! == SAE '82 == Denizens of Doom M/C '92== ------------------------------ From: john spears Date: Wed, 27 Mar 96 17:59 EST Subject: re:4.3 multi-port fuel injection I've been observing the list for awhile, thought I'd through my $.02 in. The 4.3L CPI engine is a huge improvement over the TBI version. Although it only uses one injector, the CPI design allows you to deliver the fuel where it belongs and also allows for some nice manifold air tuning in the process; thins you just can't do when you're carrying an A/F mixture. I've done about three of these engines and have turned out well. What would be ideal is to find a damaged one in the junkyard and get the manifold assembly for your engine. I use the factory ECM on most of my projects as they are fairly cheap and have all the bases covered. A little EPROM programming to cover your specifics and you're on your way! John Spears Speartech Fuel Injection Systems ------------------------------ From: john spears Date: Wed, 27 Mar 96 18:18 EST Subject: re: 96 Chevy 454 There was some talk in digest #88 about the 96 454 Chevy. This engine: RPO L29 is actually a true sequential port fuel injection engine with 8 injectors mounted on a fuel rail in the usual manner. The 96 small-blocks for trucks, i.e., 5.0L (RPO L30), and the 5.7L (RPO L31), are in fact sequential central port injected engines. GM refers to this as "SCPI". These engines use a group of eight injectors molded together at the top of the intake manifold, with a tube and poppet valve from the bottom of each injector down to it's respective port. The 4.3L for 96 also takes on this form. These engines become more difficult to adapt to other applications using their original ECM's due to the added complexity of OBD II regulations for 1996. The 454 however could be set up pretty easily using an earlier small block TPI ECM. John Spears Speartech Fuel Injection Systems ------------------------------ From: john spears Date: Wed, 27 Mar 96 19:03 EST Subject: re: TPI info In response to in digest 88 looking for TPI info: The 305 injectors are 19 lb/hr while the 350 injectors are 22 lb/hr. The fuel pressure regulators vary by year only, not by engine size. In 1985 (the first year for the TPI engine), the fuel pressure was lower; I beleive about 33 psi with idle vacuum and about 39-40 psi@xxx. It was raised in 1986 and since then it has typically been around 36 psi with idle vacuum and 45psi @xxx. An adjustable fuel pressure regulator is a very handy tuning tool on these engines as it will not only compensate for 305 injectors on a 350 engine, but also for other engine mods with a given ECM calibration! John Spears Speartech Fuel Injection Systems ------------------------------ From: "George M. Dailey" Date: Wed, 27 Mar 1996 20:09:34 -0600 Subject: Re: injector pulse width At 03:16 PM 3/27/96, you wrote: > > > Hope someone can help, > > I have put a TPI of a 305 camaro ('84 of memory) onto a 350 block. > The cam is something like a 28/63 (fairly moderate for a mild cam). > > Does anyone have any idea how much fuel the 305 injectors flow (I > think they are Bosch units) ? > > and the maximum pulse length required for the 350 using the same > injectors (using the standard 305 fuel rail regulator)? > > Is it correct the 305 uses a 38PSI regulator, while the 350 uses a > 40PSI regulator ? > > In fact does anyone have a fuel map printout for either a 305 or 350 > they could mail me ? It may make it easier to start setting up the > map. > > > Any help appreciated > > > Dan dzorde@xxx.au ============================================================================ ============> Dan, I think TPI started in 1985 and these systems are different from the '86 and up. Welcome to the TPI club, does your mouth still water when you look at it? Per Frank "Choco" Munday's book, TPFI, he states that 305/350 injectors will work reasonably well if exchanged as a complete set. This refers to the MAF type TPI systems up to '89, and exclude your '85 baby (even though it's MAF equiped). His book only covers the '86-'89 models, but I think the injector swaping rule will apply to your system also since it's a MAF type. Choco goes on to say that he can not tell the difference below 4,500rpm. Thats big in small and small in big. > >There are differences in the operating pressures. Per chilton, 44psi for 5.0 & 37psi for 5.7 22lbs/hr flow rate for the 350 per Ben Watsons chevy fuel injection book (no 305 data). BTW guys, The '89 TPI in my '58 is running great! All bugs have been worked out and I've clocked over 600 trouble free city miles already. The R700 is comming soon. Dan, if you can give the symtoms, I sure one of us gurus could help. Good luck GMD ------------------------------ From: "George M. Dailey" Date: Wed, 27 Mar 1996 20:09:37 -0600 Subject: attachment questions Thanks Will, I got your attached file in the following format. - ---------------------------------------------------------------------------- - ------------ The following is an attached File item from cc:Mail. It contains eight bit information which had to be encoded to insure successful trans- mission through various mail systems. To decode the file use the UUDECODE program. - --------------------------------- Cut Here --------------------------------- begin 644 serset.exe M35IP 0X 7 9 "8$)J3$ 0! !%!P ' +, #( S0 -( #D M Z0 .X 0 !0$ H! = 0 (@$ " 0 @xxx.T! / @ *P( #4" !- @ 5P( M )@xxx.<" #L @ , , $4# !* P Blah blah blah.... What or where can I find UUDECODE? I take it, you are using cc-Mail? Is the attached file an executable file? Thanks a million Will. GMD ------------------------------ From: Terry Faugno Date: Wed, 27 Mar 1996 18:43:50 -0800 (PST) Subject: Off topic, but related subject matter... First off, introductions. My name is Terry Faugno. I work in San Diego, California at a company called Qualcomm Inc. We researched, developed, and are now marketing digital cellular telephony equipment. My interest in DIY EFI is based on a passion for performance, and a love of tinkering. My ultimate goal is to find a Porsche 911/912 or 944 or a 924, install either a Buick 231 V6 or a small block Chevy engine, and fabricate a SMPI fuel delivery system, super or turbocharger, and, as you'll read below, a constantly variable valvetrain system. My desire is to see how much horsepower can be derived from a smallish engine (300 CID maximum), without sacrificing engine longevity. I selected the Porsche body(ies) as it has an inbuilt capability for high performance, and they're quite stylish to boot. Now the off-topic, but related post mentioned in the subject header: I've heard rumours that a company somewhere had developed a system that replaces camshafts with computer controlled solenoids to actuate the valve train. Has anyone here heard the same, or know a logical point to start searching from? From a performance standpoint, one could program a limitless variety of "virtual camshaft" profiles, like Honda's VTEC, or any of the available variable valve timing schemes. Only more so, as one is not limited to 2 profiles. That's the gist of my question. Thank you in advance for any information that any of the subscribers to this list might provide. Thanx, Terry ------------------------------ From: ricrain@xxx.net (Ric Rainbolt) Date: Wed, 27 Mar 1996 17:24:35 -0600 Subject: Re: injector pulse width > I have put a TPI of a 305 camaro ('84 of memory) onto a 350 block. > The cam is something like a 28/63 (fairly moderate for a mild cam). > > Does anyone have any idea how much fuel the 305 injectors flow (I > think they are Bosch units) ? > > and the maximum pulse length required for the 350 using the same > injectors (using the standard 305 fuel rail regulator)? > > Is it correct the 305 uses a 38PSI regulator, while the 350 uses a > 40PSI regulator ? > According to a catalog I have from Performance Fuel systems, the following Bosch injectors are used: GM 5.0 TPI is a 19 lb/hr @xxx. GM 5.7 TPI is a 22 lb/hr @xxx. At least according to this list, all GM products are 43 PSI and all Ford products are 39 PSI. Hope this helps, Ric Rainbolt ricrain@xxx.net ------------------------------ From: ricrain@xxx.net (Ric Rainbolt) Date: Wed, 27 Mar 1996 17:21:16 -0600 Subject: Re: EFI for Bosch mech. injection >Does anybody have any info on adapting the late-'60s Bosch mechanical >injection >to EFI? I understand it has been done in Germany. > I understand that the later Bosch mechanical systems had closed loop operation utilizing an O2 sensor and a "fuel frequency" valve. This valves duty cycle was varied by an analog circuit to achieve the desired level of enrichment. At some throttle level, the closed loop is defeated and the system returns to the preset levels prescibed by the air mass plate. Hope this helps, Ric Rainbolt ricrain@xxx.net ------------------------------ From: jac@xxx.us (john carroll) Date: Wed, 27 Mar 96 19:51:59 PST Subject: VW Bosch injection My name is Justin Carroll. I am using my father's account. I have a 1976 Volkswagon Bus and am looking for information about the Bosh fuel injection system that came stock in this vehicle. I would really like schematics of the controller/computer and the sensors. Does anyone know of an after market computer or know of anyone who has built a controller for the system? Thanks - ----------------------------------------------- Justin Carroll @ jac@xxx.us ------------------------------ From: Jody Shapiro Date: Thu, 28 Mar 1996 00:08:31 -0500 Subject: Re: Off topic, but related subject matter... Resend, but this time with the no RTF/WINMAIL.DAT crap from MS Exchange. Sorry about that... >From: Terry Faugno[SMTP:tfaugno@xxx.com] >Sent: Wednesday, March 27, 1996 1:43 PM >To: DIY_EFI@xxx.edu >Subject: Off topic, but related subject matter... > > First off, introductions. My name is Terry Faugno. I work in San Welcome to the list! >Now the off-topic, but related post mentioned in the >subject header: > >I've heard rumours that a company somewhere had >developed a system that replaces camshafts with >computer controlled solenoids to actuate the valve train. >Has anyone here heard the same, or know a logical point to >start searching from? From a performance standpoint, one could program a You may be referring to Lotus' active electro-hydraulic valvetrain. If so, you may want to take a look at: Dobson, C. and Drake, T. 1991 "Emissions Optimization by Camshaft Profile Switching" SAE Paper 910838 - -Jody - --- http://www.cs.cornell.edu/Info/People/jshapiro/jshapiro.htm ------------------------------ From: Jody Shapiro Date: Thu, 28 Mar 1996 00:03:06 -0500 Subject: RE: Off topic, but related subject matter... >From: Terry Faugno[SMTP:tfaugno@xxx.com] >Sent: Wednesday, March 27, 1996 1:43 PM >To: DIY_EFI@xxx.edu >Subject: Off topic, but related subject matter... > > First off, introductions. My name is Terry Faugno. I work in San Welcome to the list! >Now the off-topic, but related post mentioned in the >subject header: > >I've heard rumours that a company somewhere had >developed a system that replaces camshafts with >computer controlled solenoids to actuate the valve train. >Has anyone here heard the same, or know a logical point to >start searching from? From a performance standpoint, one could program a You may be referring to Lotus' active electro-hydraulic valvetrain. If so, you may want to take a look at: Dobson, C. and Drake, T. 1991 "Emissions Optimization by Camshaft Profile Switching" SAE Paper 910838 - -Jody - --- http://www.cs.cornell.edu/Info/People/jshapiro/jshapiro.htm begin 600 WINMAIL.DAT M>)\^(@@%`0:0" `$```````!``$``0>0!@`(````Y 0```````#H``$-@ 0` M`@````(``@`!!) &`&0!```!````# ````,``# #````"P`/#@`````"`?\/ M`0```&,`````````@2L?I+ZC$!F=;@#=`0]4`@````!D:7E?969I0&-O=6QO M;6(N96YG+F]H:6\M``,P`0`` M`",```!D:7E?969I0&-O=6QO;6(N96YG+F]H:6\M5]E9FE 8V]U;&]M8BYE;F`' ``0```"T```!2 M13H@3V9F('1O<&EC+"!B=70@QCU=O`!X,`0`` M``4```!33510`````!X`'PP!````& ```&IS:&%P:7)O0&-S+F-O``@xxx.E1%4E)91D%5 M1TY/4TU44#I41D%51TY/0%%504Q#3TU-0T]-4T5.5#I7141.15-$05DL34%2 M0T@xxx.3DV,3HT,U!-5$\Z1$E9149)0$-/54Q/34)%3D=/2$E/+5-4```` M``(!"1 !````)@0``"($```*" ``3%I&=4%J]JO_``H!#P(5`J@%ZP*#`% " M\@D"`&-H"L!S970R-P8`!L,"@S(#Q0(`<')"<1'B1W@xxx.@`P((- <74'0-$%H&UM+B'Q70J'&T^_'%\= M9P9@xxx.C0S(%!- M;R*/(Y\DKR `;R8/'TM$@$E97T5&24 %H!9U%: &T"X)\& 01 $(" :0?!)('?]!;!K01$& M`CEO/><\A2?@xxx.;P?@FT.-(/S\< M22=V0G!1`0L@xxx. @K&$@(?$\L&X@4'-&P?YW1T 6$%#P M42!1?TY_/OZW#;!5,!6@<#@A5I!S$[-75C06$ M18P>18T)0<_\1@ & !" # M\$T@4&)"0=P:7HPX$&Q-X @4$/_744IP -@&D!B, 8`7=%QXU(B!@!!12G M87,1("&"4# X,SA'S"U*701P>8=FB)!UQ6@xxx.B\O=XF@(C!!X 6A1R@0 M8B Q$B]);@(0+\Q094KP8C O:EUA2P!K`V"+ARZ),&UUQ14Q``&-D ```P`0 M$ $````#`!$0`````$ `!S @&1;\8AR[`4 `"# @&1;\8AR[`1X`/0`!```` .!0```%)%.B `````L;P` ` end ------------------------------ From: lambs@xxx.au (Stephen Lamb) Date: Thu, 28 Mar 1996 16:09:47 +1100 Subject: Re: Off topic, but related subject matter... > I've heard rumours that a company somewhere had developed a system >that replaces camshafts with computer controlled solenoids to actuate the >valve train. Has anyone here heard the same, or know a logical point to >start searching from? From a performance standpoint, one could program a >limitless variety of "virtual camshaft" profiles, like Honda's VTEC, or any >of the available variable valve timing schemes. Only more so, as one is not >limited to 2 profiles. I think it was Renault (?) that developed a pneumatically operated valve system for their F1 engines some years back. Don't know much about it or how successful it was. Cheers Stephen Lamb Dept. of Defence DSTO, AMRL 506 Lorimer Street Fishermans Bend VIC 3207 Australia Tel: +61 3 9626 7525 Fax: +61 3 9626 7089 IZCC #180 ------------------------------ From: Bob Valentine Date: Thu, 28 Mar 1996 00:33:01 -0500 (EST) Subject: Re: Off topic, but related subject matter... On Thu, 28 Mar 1996, Stephen Lamb wrote: > > I've heard rumours that a company somewhere had developed a system > >that replaces camshafts with computer controlled solenoids to actuate the > >valve train. Has anyone here heard the same, or know a logical point to > >start searching from? Try this month's Automotive Industries. It's the annual "Motors" issue... They have a few pages devoted to a system that's been developed to do valve acutaction with electromagnets - efficiently! > >From a performance standpoint, one could program a > >limitless variety of "virtual camshaft" profiles, like Honda's VTEC, or any > >of the available variable valve timing schemes. Only more so, as one is not > >limited to 2 profiles. Just about. The problem for the longest time has been acutating the valves without drawing huge amounts of electrical power. Just think, 20 years from now you can make your 500hp V8 idle sounding like a 200k mile junker. Press the keypad and you're back to your normal profile. 8^) --> Bob Valentine <-- --> ravalent@xxx.com <-- "Experience varies directly with equipment ruined" ------------------------------ From: David Channon Date: Thu, 28 Mar 1996 18:01:23 +1100 (EST) Subject: The EFI project status Hi, Sorry but I am a very keen newbie to this group and I am interested in building the EFI project you are developing. I would like to know the status as the web page states that the board will be ready this month. In addition, how do I place my name down to purchase the parts and board(s) etc etc as I assume you can arange a bulk purchase. Finally, can you tell me if the project EFI system is suited to a turbo application and what information (Books etc) cover EFI and turbos (I am grafting a duel turbo system to a 289/302W V8). Thanks in advance, Regards David. ps: If this is not an appropriate place to ask these question please direct me to an appropriate forum. - -- - ----------------------------------------------------------------- David Channon .-_|\ Department of Computer Science / \ The University of Newcastle \.--._/ NSW, 2308, AUSTRALIA v Email : dchannon@xxx.au URL : http://wwwcs.newcastle.edu.au/Research/VMRG/dchannon.html - ----------------------------------------------------------------- "Virtual Memory is like an orgasm, It's better if you don't fake it!" -- S Cray ------------------------------ From: Terry Faugno Date: Wed, 27 Mar 1996 23:00:27 -0800 (PST) Subject: Re: Off topic, but related subject matter... >I think it was Renault (?) that developed a pneumatically operated valve >system for their F1 engines some years back. Don't know much about it or >how successful it was. All righty then! Thanx for the lead. I've cruised to several Renault sites and dropped a few enquiries about. Should be interesting to see what kind of response I get. Thanx, Terry ------------------------------ From: SJCHU@xxx.Edu Date: Thu, 28 Mar 1996 00:17:36 -0800 (PST) Subject: Re: Off topic, but related subject matter... A company out here in Southern California had sucessfully ran an engine with electric solenoid. Actuaaly, two company had bbeen developing the technology. I think one of them is call Digi-Valve or something like that. can't remeber. the article was in Turbo magazine. Jacky C. ------------------------------ From: "Jim Staff" Date: Thu, 28 Mar 1996 09:34:40 GMT Subject: Re: Multi Spark Ignition... > I really doubt that kind of improvement from an engine from a > relatively modern vehicle. What year? What engine? And most > importantly, what was the base ignition system that was costing them > 40% power? I assume this is peak power. What about torque readings > across the rest of the rpm range? What kind of condition was the rest > of the engine in? I changed plug wires and picked up more than > that, but my wires were in really old and in bad shape(I'm a > cheapskate, see? Also a skeptic:) This is what I know about the engine, it was made in the early 80's, and is used in racing. The multi-spark ignition the vehicle isn't industry made it DIY. That was why I was fondering if making it switch very quickly (On the order of 500-750ns) would contribute to my power. At that speed I could have multi spark at any RPM. My application only goes to 4K anyway. The main point of my first post was whether or not this is a good idea, and would it improve my efficiency? Jim Staff ------------------------------ End of DIY_EFI Digest V1 #89 **************************** 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".