DIY_EFI Digest Friday, 1 November 1996 Volume 01 : Number 331 In this issue: Motorola pressure sensors Re: Motorola pressure sensors Re: It Howls with small throttle bodies Re: It Howls with small throttle bodies Autronic Contact Address Re: Excessive Ignition Timing Advance Effects VIRUS ALERT BurnRate/Octane/RPM/Advance See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: jedc@xxx.au (Arthur Clampitt) Date: Thu, 31 Oct 1996 04:55:21 -0500 Subject: Motorola pressure sensors Can anyone point me to a US supplier of Motorola pressure sensors ( specifically MPX4250AP) Australian distributors have none and are only willing to order from the States in multiples of 20 , I just want a couple , I cant see them in Digi-Key, Mouser etc "There is no cure for birth and death , save to enjoy the interval" Coffs Harbour NSW Australia ------------------------------ From: cloud@xxx.edu (tom cloud) Date: Thu, 31 Oct 1996 07:28:12 -0600 Subject: Re: Motorola pressure sensors >Can anyone point me to a US supplier of Motorola pressure sensors ( >specifically MPX4250AP) > >Australian distributors have none and are only willing to order from the >States in multiples of 20 , I just want a couple , I cant see them in >Digi-Key, Mouser etc >"There is no cure for birth and death , save to enjoy the interval" > >Coffs Harbour NSW Australia Try Newark Electronics Tom Cloud ------------------------------ From: Michael Manry Date: Thu, 31 Oct 1996 07:34:37 -0800 (PST) Subject: Re: It Howls with small throttle bodies Does anyone have the address for Autronic??? I tried looking them up thru a couple of sources and struck out . Thanks Mike Manry ShadeTree racing On Thu, 31 Oct 1996, 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) > > ------------------------------ From: Jonathan Barnes Date: Thu, 31 Oct 1996 19:10:08 Subject: Re: It Howls with small throttle bodies >now running twin weber 45mm throttle bodies. >You wouldn't happen to know where I could get some chokes made up? >bye, > >Jeremy, Sydney AUSTRALIA If an english supplier of Webber parts who could ship bits to you is of interest mail me and I will dig one out. jonathan@xxx.net Jonathan. | Barnes's Theorum: For every foolproof device | | there exists a fool greater than the proof | ------------------------------ From: Doug Robson Date: Fri, 01 Nov 1996 10:48:10 +1100 Subject: Autronic Contact Address Michael Manry wrote: > > Does anyone have the address for Autronic??? I tried looking them up thru > a couple of sources and struck out . > Thanks > > Mike Manry > ShadeTree racing > The designer of Autronic is Richard Aubert His address is 24 Heather Grove Belgrave south Victoria Australia 3160 Phone 61 - 3 - 97544333 - -- |===============================================================| | 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: Mark Mason Date: Thu, 31 Oct 1996 19:24:30 -0500 Subject: Re: Excessive Ignition Timing Advance Effects John Faubion wrote: > First off just where are you finding 120 octane fuel and why would you need > it for an 8:1 compression ratio? > > 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. The compression ratio and fuel are just an example in which I would think excessive Ignition Advance couldn't possibly cause knock because of the fuel's anti-knock properties. The EGT temp method sounds like a good idea however I'd like to use the sensed variable as feedback on my ECM. In this case I think the temp change might be too slow to be used in a closed loop system. If EGT increases with RPM ( I think thats what should happen? ), with the engine accelerating, the EGT change due to parameters other than excessive ignition timing would confuse the ECM because the change is indistinguishable in regards to the parameter which caused it. I'm going to do some tests to validate my theory. Do you and anyelse have hands on experience with this method? Mark Mason. ------------------------------ From: cloud@xxx.edu (tom cloud) Date: Thu, 31 Oct 1996 19:44:02 -0600 Subject: VIRUS ALERT BEWARE: Mongol hordes are massing South of a border (somewhere) and have let loose a most destructive virus. It will cause the paint to flake off your computer and body hair to fall in between the keys of your keyboard. This virus is most active after you have turned the power OFF on your computer and it multiplies most rapidly when you are not in the room. You can identify this virus by a subject line that has the word "Subject" in it or the phrase "VIRUS ALERT". [Sorry, I just get irritated at people who spread "chain" virus alerts. -- Might as well have a little fun with it.] Tom Cloud ------------------------------ From: Dave Zug Date: Thu, 31 Oct 1996 23:18:42 -0500 Subject: BurnRate/Octane/RPM/Advance hello, i'm back, and have learned enough to sound intelligent to the amateurs, but i wont fool any of you, i'm still learning and i'm no engineer, i'm a programmer. anyway, still poking away at the GM-P4, Q1: can anyoue positively identify the chipset? 6801? Q2: can someone explain optimim spark advance calculation? Octane/burn rate/piston speed/distance to TDC/??/?? used here? extra credit: for Q2- factor in higher intake pressure (15psi of turbo boost) considerations. whats the reasoning behind reduced advance under boost? the reason i ask is i want to alter my spark table for higher octane fuel and/or increased boost and want to re-calculate each table entry. BTW: anyone have an OTC pathfinder II cartridge for sale? $100 offered. ------------------------------ End of DIY_EFI Digest V1 #331 ***************************** 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".