DIY_EFI Digest Thursday, 31 October 1996 Volume 01 : Number 330 In this issue: Re: It Howls with small throttle bodies Re: D-Jet trigger points Re: Virus Re: Virus How to unsubscribe? Re: How to unsubscribe? Re: How to unsubscribe? Re: It Howls with small throttle bodies Re: How to unsubscribe? GM TPI intake wanted Re: It Howls with small throttle bodies Re: GM TPI intake wanted Re: It Howls with small throttle bodies Re: It Howls with small throttle bodies Excessive Ignition Timing Advance Effects Re: GM TPI intake wanted Re: It Howls with small throttle bodies Re: Excessive Ignition Timing Advance Effects Re: It Howls with small throttle bodies See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Doug Robson Date: Wed, 30 Oct 1996 22:29:29 +1100 Subject: Re: It Howls with small throttle bodies James Weiler wrote: > > Hi Doug...any idea why the smaller TB works so much better? Turbulence > maybe?? > Nifty story...reminds me that bigger isn't always better. > later > jw Ithink there are many reasons 1. Not enough venturi effect in big ones and stalled air speed at the butterfly. 2. too much side incursion into flow path 3. pulse rejection in velocity in/out who knows - -- |===============================================================| | When I die, | | I want to go in my sleep, like my grandfather, | | not screaming like the passengers in his car. | |---------------------------------------------------------------| | Doug Robson (H) mailto:doug@xxx.au | | (W) mailto:Doug.Robson@xxx.com | | Sydney, Australia http://www.cia.com.au/doug | |---------------------------------------------------------------| | Club Car Racing Register of NSW | Thank God | | 1992/93 Under 2 litre State Champion | for | | http://www.cia.com.au/doug/ccrrnsw.html | Gravity | |===============================================================| ------------------------------ From: wrm@xxx.za (Wouter de Waal) Date: Wed, 30 Oct 1996 14:25:23 +0200 Subject: Re: D-Jet trigger points Hi all Frank asks: > Has anyone with the Bosch D-Jet FI system ever figured out a >way to get rid of the FI trigger points in the distributor? (for the >purpose of using a different distributor) The only ways I can think >of is to use some sort of sensor on the flywheel or fan to trigger a >spdt switch or to trigger off of the coil and somehow compensate for >the spark advance in the injector firing (such as with a speed >dependant injector delay) Any ideas, comments, etc ? I'm planning to use the D-jet points for cam position, in conjunction with a sensor on the flywheel. The points work off the cam, if you sense the flywheel only you lose that information. So you _have_ to have a sensor on the cam. I don't know how critical the timing of those points are, remember when you set the spark timing you're affecting the D-jet timing and it doesn't seem to matter much. Wouter ------------------------------ From: cloud@xxx.edu (tom cloud) Date: Wed, 30 Oct 1996 07:35:00 -0600 Subject: Re: Virus >>If the program is not stopped, the computer's processor will >>be placed in an nth-complexity infinite binary loop - which can >>severely damage the processor if left running that way too long. >>Unfortunately, most > >Does anybody know potential values for n? Does it only damage the >processor for certain values of n or are all values dangerous? > >Martin I'd just stick to 'm' and 'o'. Tom Cloud ------------------------------ From: Todd King Date: Wed, 30 Oct 96 09:08:00 PST Subject: Re: Virus <<< From: brewer@xxx.com (John Brewer) Date: Tue, 29 Oct 1996 08:46:51 -0500 Subject: Re: Virus > > Really? Wow! So executing loop instructions will destroy the processor, eh? I > better inform the big brass immediately! I'll probably be promoted as a >result! > Give me a break! I'm an Engineer and write simulations for a living, I should have known better. You wouldn't believe the heat I have taken for trying to be nice and informative. I would have received less blistering (and fewer) responses for soliciting kiddie porn! JB >>> Just kidding, JB... Just kidding. Also, next time be sure to show 'em the pictures first! Todd Todd_King@xxx.com ------------------------------ From: Frank_Mallory@xxx.com (Frank Mallory) Date: Wed, 30 Oct 1996 07:10:10 -0500 Subject: How to unsubscribe? Could somebody please give me some tips on removing my old account from this list? Majordomo keeps saying I am not a member. ------------------------------ From: Doug Rorem Date: Wed, 30 Oct 1996 15:34:30 -0600 Subject: Re: How to unsubscribe? 30-oct-96 The problem is you subscribed using: frank.mallory@xxx.com [output from 'WHO DIY_EFI' sent to majordomo] Apparently your login name went from all lower case to mixed case. Since Majordomo is picky about entire email addresses matching... you either have to send the unsubscribe message from that user name or else have the list maintainer remove you. - -- 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: Jonathan Barnes Date: Wed, 30 Oct 1996 21:55:39 Subject: Re: How to unsubscribe? >Could somebody please give me some tips on removing my old account from this >list? Majordomo keeps saying I am not a member. > Recived when I joined, I hope this helps ***************************************** REPLY-TO: Majordomo@xxx.edu - -- Welcome to the diy_efi mailing list! If you ever want to remove yourself from this mailing list, you can send mail to "Majordomo" with the following command in the body of your email message: unsubscribe diy_efi Jonathan Barnes Here's the general information for the list you've subscribed to, in case you don't already have it: ================================================================ Do - It - Yourself Electronic Fuel Injection ================================================================ To subscribe: Send to Majordomo@xxx.edu subscribe [list name] [your email address *only* if different than your "From" address] To unsubscribe: Send to Majordomo@xxx.edu unsubscribe [list name] [your *registered* email address if different than your "From" address] For help: Send "help" to Majordomo@xxx. To post: Send to "DIY_EFI@xxx.edu" Digest mode: This is available for all of the mailing list. Send "lists" to Majordomo for a listing a mailing lists served. To switch to the digest mode, unsubscribe to the regular list and then subscribe to the digest version (i.e., diy_efi-digest). Charter: This mailing-list is *strictly* dedicated to the discussion of topics related to EFI design and modification. I would like to see discussion on control algorithms, hardware, electronics, and sensor/sensor-interface designs. Additionally, modification and adaptations of OEM ECU's would also be welcomed. For more information: archive http://efi332.eng.ohio-state.edu/ diy_efi http://www.cpsc.ucalgary.ca/~fridman/diy_efi efi332 http://www.cim.swin.edu.au/~aden/web-docs/efi332/332_index.html John S. Gwy ******************************************* Jonathan. | Barnes's Theorum: For every foolproof device | | there exists a fool greater than the proof | ------------------------------ From: Jeremy Pronk Date: Thu, 31 Oct 1996 09:38:19 +1100 (EST) Subject: Re: It Howls with small throttle bodies On Wed, 30 Oct 1996, Doug Robson wrote: > I installed an Autronic SMC computer and individual 50 mm throttle > bodies. Result 160-170 bhp :( ( sad face ). > I have recently had a set of 45 mmm bodies made with same diameter at > ram intake end but 45 at butterfly. result 205 bhp and more torque. > Drove it on track on Sunday and it howls. Im amazed at the difference of > 5mm makes. all other parts of the engine are unchanged since previous > set ( except bearings). I have an haltech E6 installed on my alfa. I used to run twin webers (36mm), but with the efi it is now running twin weber 45mm throttle bodies. I have to say that "takeoff" isnt that much fun (esp. up hills). It goes really well above about 3500rpm+, seems to get a lot of torque steer? as well if I hammer it. You wouldn't happen to know where I could get some chokes made up? I really want to choke them down to ~40mm, because this is the "Drive around" car (ie, I am not interested in the 2000rpm power band > 5000rpm). bye, Jeremy, Sydney AUSTRALIA http://www.st.nepean.uws.edu.au/~jpronk/ '83 AlfaSud Ti (Haltech E6 efi) ------------------------------ From: Craig Pugsley Date: Thu, 31 Oct 1996 10:03:57 +1100 (EST) Subject: Re: How to unsubscribe? > > Could somebody please give me some tips on removing my old account from this > list? Majordomo keeps saying I am not a member. > "me-too".. I tried about 5 different email address combinations (I subscribed to the digest version & want to unsubscribe from the interactive) Craig. pugsley@xxx.au (maybe ;-) ------------------------------ From: Daniel Burk Date: Wed, 30 Oct 1996 19:33:50 -0800 Subject: GM TPI intake wanted I'm looking for a GM TPI intake, runners, plenum, throttle body, fuel rails, injectors, and bracketry. Basically, I'm after everything but the harness and the computer. What's the going rate? It doesn't have to be clean, just intact. -- Dan. ------------------------------ From: cloud@xxx.edu (tom cloud) Date: Wed, 30 Oct 1996 18:18:23 -0600 Subject: Re: It Howls with small throttle bodies >On Wed, 30 Oct 1996, Doug Robson wrote: > >> I installed an Autronic SMC computer and individual 50 mm throttle >> bodies. Result 160-170 bhp :( ( sad face ). >> I have recently had a set of 45 mmm bodies made with same diameter at >> ram intake end but 45 at butterfly. result 205 bhp and more torque. >> Drove it on track on Sunday and it howls. Im amazed at the difference of >> 5mm makes. all other parts of the engine are unchanged since previous >> set ( except bearings). > >I have an haltech E6 installed on my alfa. I used to run twin webers >(36mm), but with the efi it is now running twin weber 45mm throttle >bodies. I have to say that "takeoff" isnt that much fun (esp. up hills). >It goes really well above about 3500rpm+, seems to get a lot of torque >steer? as well if I hammer it. > >You wouldn't happen to know where I could get some chokes made up? I >really want to choke them down to ~40mm, because this is the "Drive >around" car (ie, I am not interested in the 2000rpm power band > 5000rpm). Now I'm confused.... With my limited knowledge and cranial ability, I thought that throttle size had little effect on FI. I can see that a larger TB gives less velocity and therefore less momentum and mixture of the fuel/air, but can anyone 'splain to this ole boy how to determine a TB size (talking normally aspirated). Tom Cloud ------------------------------ From: "George M. Dailey" Date: Wed, 30 Oct 1996 18:52:38 -0600 (CST) Subject: Re: GM TPI intake wanted At 07:33 PM 10/30/96 -0800, you wrote: >I'm looking for a GM TPI intake, runners, plenum, throttle body, fuel >rails, injectors, and bracketry. Basically, I'm after everything but the >harness and the computer. > >What's the going rate? It doesn't have to be clean, just intact. > > -- Dan. Complete motors go for about $1,000.00 (salvage) in Mississippi, if you can find one. A nation wide salvage parts store quoted a complete manifold for about $400.00. I know of at least one hill-billy who pulled the motor out of his IROC and bent a ram tube. Yes, he tied the chain to the ram tube. After finding out the price of a replacement tube, he simply threw away the whole intake and replaced it with a carb & manifold. Rumor has it that his parents were related to each other prior to their marriage. A buddy of mine in Lakeland/Orlando florida found a 5.7 TPI motor for $850.00 and a 5.0L for $750 (no ecms). You're on the right path bud. You might consider buying a complete total'd car and selling the balance. Just to encourage you, GM made well over 1,000,000 TPI units. The hill billies can't get them all. GMD ------------------------------ From: Doug Robson Date: Thu, 31 Oct 1996 12:16:49 +1100 Subject: Re: It Howls with small throttle bodies Jeremy Pronk wrote: > > On Wed, 30 Oct 1996, Doug Robson wrote: > > > I installed an Autronic SMC computer and individual 50 mm throttle > > bodies. Result 160-170 bhp :( ( sad face ). > > I have recently had a set of 45 mmm bodies made with same diameter at > > ram intake end but 45 at butterfly. result 205 bhp and more torque. > > Drove it on track on Sunday and it howls. Im amazed at the difference of > > 5mm makes. all other parts of the engine are unchanged since previous > > set ( except bearings). > > I have an haltech E6 installed on my alfa. I used to run twin webers > (36mm), but with the efi it is now running twin weber 45mm throttle > bodies. I have to say that "takeoff" isnt that much fun (esp. up hills). > It goes really well above about 3500rpm+, seems to get a lot of torque > steer? as well if I hammer it. > > You wouldn't happen to know where I could get some chokes made up? I > really want to choke them down to ~40mm, because this is the "Drive > around" car (ie, I am not interested in the 2000rpm power band > 5000rpm). > > bye, > > Jeremy, Sydney AUSTRALIA > http://www.st.nepean.uws.edu.au/~jpronk/ > '83 AlfaSud Ti (Haltech E6 efi) I would recommend BRS Motorsport in Blacktown. They are not quick but they are very very good. Speak to Phill Ryall or Bob Bridge 96216214 unit 3 / 10-12 Carnegie Pl. Blacktown 2148 Phil Builds my manifolds Bob builds my engines - -- |===============================================================| | When I die, | | I want to go in my sleep, like my grandfather, | | not screaming like the passengers in his car. | |---------------------------------------------------------------| | Doug Robson (H) mailto:doug@xxx.au | | (W) mailto:Doug.Robson@xxx.com | | Sydney, Australia http://www.cia.com.au/doug | |---------------------------------------------------------------| | Club Car Racing Register of NSW | Thank God | | 1992/93 Under 2 litre State Champion | for | | http://www.cia.com.au/doug/ccrrnsw.html | Gravity | |===============================================================| ------------------------------ From: Jeremy Pronk Date: Thu, 31 Oct 1996 12:38:09 +1100 (EST) Subject: Re: It Howls with small throttle bodies On Wed, 30 Oct 1996, tom cloud wrote: > Now I'm confused.... With my limited knowledge and cranial ability, > I thought that throttle size had little effect on FI. I can see that > a larger TB gives less velocity and therefore less momentum and > mixture of the fuel/air, but can anyone 'splain to this ole boy > how to determine a TB size (talking normally aspirated). Ok, to my understanding a "stock" type car has throttle bodies optimized for nice city driving (ie good power down low). Now if you increase this size heaps, the velocity of air in the throttle bodies is very low at low rpm because of the venturi? effect. But at high rpm's the car should have an advantage (along with other mods) of being able to suck in more air/fuel because of the greater tb size (thats what I was saying). I didnt put the 45mm's on, but I want to choke them down a bit to increase low rpm velocity and there fore low speed drivablity. Please correct my if I am wrong. If there is a formula to calculate the size, please say so (the car used to run carbies). (sorry if this is to far off topic) regards, Jeremy, Sydney AUSTRALIA http://www.st.nepean.uws.edu.au/~jpronk/ '83 AlfaSud Ti (Haltech E6 efi) ------------------------------ From: Mark Mason Date: Wed, 30 Oct 1996 21:12:27 -0500 Subject: Excessive Ignition Timing Advance Effects Scenario: IC engine compression ratio = 8:1 fuel octane = 120 unleaded engine temp = 70 Deg C. ignition timing = 20 Deg. BTDC RPM = 1000 If I start increasing the ignition advance out to say 40 Deg. BTDC, what engine parameter or by-product can I measure which will tell me which Ignition setting gave me peak torque at the lowest combustion chamber temperature other than actually measuring the two parameters? Thanks in Advance. Mark. ------------------------------ From: "William A. Sarkozy" Date: Wed, 30 Oct 1996 22:14:18 -0800 Subject: Re: GM TPI intake wanted At 07:33 PM 10/30/96 -0800, you wrote: >I'm looking for a GM TPI intake, runners, plenum, throttle body, fuel >rails, injectors, and bracketry. Basically, I'm after everything but the >harness and the computer. > >What's the going rate? It doesn't have to be clean, just intact. > > -- Dan. > >Dan, I paid $300 a year ago for everything but the injectors. It was from a 305 Pontiac...I don't know if there is any difference between the 305 & 350 versions. If you're after a lot of grunt, you won't need the injectors anyway....you'll need more fuel. If you run boost, 38 lb injectors will net you about 625 HP @xxx. ------------------------------ From: lambs@xxx.au (Stephen Lamb) Date: Thu, 31 Oct 1996 13:49:45 +1100 Subject: Re: It Howls with small throttle bodies >On Wed, 30 Oct 1996, tom cloud wrote: > >> Now I'm confused.... With my limited knowledge and cranial ability, >> I thought that throttle size had little effect on FI. I can see that >> a larger TB gives less velocity and therefore less momentum and >> mixture of the fuel/air, but can anyone 'splain to this ole boy >> how to determine a TB size (talking normally aspirated). > >Ok, to my understanding a "stock" type car has throttle bodies optimized >for nice city driving (ie good power down low). Now if you increase this >size heaps, the velocity of air in the throttle bodies is very low at low >rpm because of the venturi? effect. But at high rpm's the car should have >an advantage (along with other mods) of being able to suck in more >air/fuel because of the greater tb size (thats what I was saying). I didnt >put the 45mm's on, but I want to choke them down a bit to increase low rpm >velocity and there fore low speed drivablity. Please correct my if I am >wrong. If there is a formula to calculate the size, please say so (the car >used to run carbies). Jeremy, I seem to remember seeing such a formula in the Haynes Weber carby manual. Unfortunately I don't have it here in front of me, but will check tonight at home and get back. Of course, this information is for carby's, but would still be applicable (right ??...............waits for the avalanche of contradictory e-mail) BTW, my experience is with Datsun L-series 6's and the general consensus with these engines is that the 45's really only begin to work properly on a race engine operating mostly high in the rev band. If you want flexibility - - and for a street car this is more important (IMHO) - then 40's are the way to go. Just my 2c (sorry to be a little of topic) 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: "John Faubion" Date: Wed, 30 Oct 1996 21:47:15 -0600 Subject: Re: Excessive Ignition Timing Advance Effects > Scenario: IC engine > compression ratio = 8:1 > fuel octane = 120 unleaded First off just where are you finding 120 octane fuel and why would you need it for an 8:1 compression ratio? > engine parameter or by-product can I measure which will tell me which > Ignition setting gave me peak torque at the lowest combustion chamber I'd watch the exhaust gas temperature. Maximum EGT usually coincides with the torque peak across the rpm range. Once the EGT drops on the side of lean detenation occurs and CHT goes up and on the other side both CHT and EGT drop. John Faubion ------------------------------ From: Doug Robson Date: Thu, 31 Oct 1996 18:05:57 +1100 Subject: Re: It Howls with small throttle bodies Stephen Lamb wrote: > > >On Wed, 30 Oct 1996, tom cloud wrote: > > > >> Now I'm confused.... With my limited knowledge and cranial ability, > >> I thought that throttle size had little effect on FI. I can see that > >> a larger TB gives less velocity and therefore less momentum and > >> mixture of the fuel/air, but can anyone 'splain to this ole boy > >> how to determine a TB size (talking normally aspirated). > > > >Ok, to my understanding a "stock" type car has throttle bodies optimized > >for nice city driving (ie good power down low). Now if you increase this > >size heaps, the velocity of air in the throttle bodies is very low at low > >rpm because of the venturi? effect. But at high rpm's the car should have > >an advantage (along with other mods) of being able to suck in more > >air/fuel because of the greater tb size (thats what I was saying). I didnt > >put the 45mm's on, but I want to choke them down a bit to increase low rpm > >velocity and there fore low speed drivablity. Please correct my if I am > >wrong. If there is a formula to calculate the size, please say so (the car > >used to run carbies). > > Jeremy, > > I seem to remember seeing such a formula in the Haynes Weber carby manual. > Unfortunately I don't have it here in front of me, but will check tonight > at home and get back. Of course, this information is for carby's, but > would still be applicable (right ??...............waits for the avalanche > of contradictory e-mail) > > BTW, my experience is with Datsun L-series 6's and the general consensus > with these engines is that the 45's really only begin to work properly on a > race engine operating mostly high in the rev band. If you want flexibility > - and for a street car this is more important (IMHO) - then 40's are the > way to go. > > Just my 2c (sorry to be a little of topic) > > 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 Well im talking about 2 litre twin cam * valve with 200 bhp at 7500 - -- |===============================================================| | When I die, | | I want to go in my sleep, like my grandfather, | | not screaming like the passengers in his car. | |---------------------------------------------------------------| | Doug Robson (H) mailto:doug@xxx.au | | (W) mailto:Doug.Robson@xxx.com | | Sydney, Australia http://www.cia.com.au/doug | |---------------------------------------------------------------| | Club Car Racing Register of NSW | Thank God | | 1992/93 Under 2 litre State Champion | for | | http://www.cia.com.au/doug/ccrrnsw.html | Gravity | |===============================================================| ------------------------------ End of DIY_EFI Digest V1 #330 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. 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