DIY_EFI Digest Friday, February 18 2000 Volume 05 : Number 067 In this issue: Re: Peak temp of combustion Perfect Power fuel injection system info? Re: Dual ign system question Re: Peak temp of combustion Re: Peak temp of combustion See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Thu, 17 Feb 2000 23:36:40 -0500 From: Seth Subject: Re: Peak temp of combustion I don't think there is a perfect correlation between combustion temp and NOx production. At lambda 1.1, combustion temperature is still high, but perhaps the excess oxygen contributes to the higher NOx. I was always taught a slightly fuel rich of stoich (mixture) was hottest. Too rich and you waste heat, and imperfections in the homogenization of the fuel and air in the intake charge result in un- or slower burning areas, and lower peak combustion temp. But if you want a high EGT, which isn't exactly the same as combustion temp, as it is after expansion, all you really need to do is retard the ignition timing. just 2 cents worth - -Seth (the king of the comma splice) Phil Lamovie wrote: > > Perfect topic for flame war !!! > > The highest combustion temps occur at Lambda 1.1 > > This also coincides with peak NOx development as NOx is > temperature dependent. > > Unfortunately for petrol it is also the highest thermal eff. > > This gives rise to the expression " lean cruise " a trick the > manufacturers use to artificially raise the fuel economy numbers. > > The drive cycle test do not use a speed higher than 92 km/hr so the > script kiddies at the ECU mapping centers write little algs such as > > is vehicle speed 95 km/hr + > is the engine temp over 65 deg/C > has the throttle movt. been less than 5% per 10 sec > is the rate of accel less than 5% > goto lean burn table > > Reason for the table is simple. The A/F ratio is beyond the range of > that technological slight of hand the oxygen " switch ". > > Phil > > ---------------------------------------------------------------------------- > To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) > in the body of a message (not the subject) to majordomo@xxx.org - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 17 Feb 2000 22:02:24 -0800 From: "The Holling's" Subject: Perfect Power fuel injection system info? This is a multi-part message in MIME format. - ------=_NextPart_000_00DC_01BF7992.ABE71EE0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Talking further about Perfect Power engine management systems, has = anyone tried the Micro Injection Control, Professional Engine Control or = any other of their fuel/spark setups? - -Jesse - ------=_NextPart_000_00DC_01BF7992.ABE71EE0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Talking further about Perfect Power = engine=20 management systems, has anyone tried the Micro Injection=20 Control, Professional Engine Control or any other of their = fuel/spark=20 setups?

-Jesse

- ------=_NextPart_000_00DC_01BF7992.ABE71EE0-- - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 17 Feb 2000 22:27:06 -0800 From: garwillis@xxx.com (Garfield Willis) Subject: Re: Dual ign system question On Thu, 17 Feb 2000 09:54:31 -0600 (CST) Roger Heflin wrote: >On my car right now I have two fully functional ignition systems. >Both have coils and plug wires, on one system is setup to generate >spark at one time. Is it possible to have one wire running to a plug >and two different systems feeding that wire with spark? Would one >coil sparking backfeed the other in a bad manner and possibly damage >one system or both systems? > >One system is a DIS system and the other is a basically a classic >coil/distributor type setup. I would expect both systems to fire at >roughly the same time, but I could adjust the dis system to fire >several degrees after the optimal fireing position that would be taken >by the coil/distrubitor setup. WHOA, I just noticed this. You're talking about joining a dizzy IGN with a DIS/wastefire system!!?? I wasn't following the thread closely enough, I see. If your DIS system is a wastefire system, I take back what I said about the MSD coil-joiners being suitable. I don't know of a way to combine these two types of systems, because the dizzy IGN wants to fire the plugs all in the same polarity, and the DIS wants to fire the plugs in pairs of opposite polarity. There exist coil-joiners for waste-fire systems, if you want to combine two of those IGN systems in a redundant pair, as well as the MSD joiners, if you want to join two dizzy-based systems (one dizzy w/two pickups & coils), but I don't know of any way to mix up the two (DIS with dizzy) when firing the same set of plugs. Shoulda stayed out of something I wasn't paying close attention to. Argh. Sorry for the mislead. Gar - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Fri, 18 Feb 2000 06:46:30 -0500 From: "nacelp" Subject: Re: Peak temp of combustion > Perfect topic for flame war !!! Now if you had mistated something maybe flames, but I didn't see anything like that here. I've heard the EPA is no longer allowing the lean cruise modes, for special conditions. Also, recall a blurb the GM would get a hefty fine if they say anymore of it. Grumpy The EPA gets a copy of all the source code, documentation for all cars manufactured in the US, and imported here. To bad the manufacturers are following GM lead in igfnore the mandate of disclosing the source code for all this stuff. Been going on for like 20 years now. I wonder how much that has cost them. > The highest combustion temps occur at Lambda 1.1 > > This also coincides with peak NOx development as NOx is > temperature dependent. > > Unfortunately for petrol it is also the highest thermal eff. > > This gives rise to the expression " lean cruise " a trick the > manufacturers use to artificially raise the fuel economy numbers. > > The drive cycle test do not use a speed higher than 92 km/hr so the > script kiddies at the ECU mapping centers write little algs such as > > is vehicle speed 95 km/hr + > is the engine temp over 65 deg/C > has the throttle movt. been less than 5% per 10 sec > is the rate of accel less than 5% > goto lean burn table > > Reason for the table is simple. The A/F ratio is beyond the range of > that technological slight of hand the oxygen " switch ". > > Phil > > > > -------------------------------------------------------------------------- - -- > To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) > in the body of a message (not the subject) to majordomo@xxx.org > - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Fri, 18 Feb 2000 06:56:36 -0500 From: Seth Subject: Re: Peak temp of combustion Um, you can't go lean because of NOx production. The reducing section of the catalyst needs an oxygen free environment in order to get rid of NOx. That means stoich or fuel rich (lamba less than or equal to 1). As soon as you hit oxygen rich, the reducing section of the cat basically stops working. One product of first half of this cat is oxygen which goes into the second half of the cat which oxidizes the HC and CO. So you can only go stoich or fuel rich these days. Fuel rich works okay with an air pump feeding air between the two parts of the cat. Fuel lean screws you over on NOx and you can't pass a governmental emissions text. That's why no lean cruise mode. Now the lean, light throttle (at "lean cruise") of previous years could squeak by, by virtue of low combustion temp, hence low NOx production. But as we go to TLEV and LEV, you can't do it anymore. 2 more cents - -Seth nacelp wrote: > > > Perfect topic for flame war !!! > > Now if you had mistated something maybe flames, but I didn't see anything > like that here. > I've heard the EPA is no longer allowing the lean cruise modes, for special > conditions. > Also, recall a blurb the GM would get a hefty fine if they say anymore of > it. > Grumpy > The EPA gets a copy of all the source code, documentation for all cars > manufactured in the US, and imported here. To bad the manufacturers are > following GM lead in igfnore the mandate of disclosing the source code for > all this stuff. Been going on for like 20 years now. I wonder how much > that has cost them. > > > The highest combustion temps occur at Lambda 1.1 > > > > This also coincides with peak NOx development as NOx is > > temperature dependent. > > > > Unfortunately for petrol it is also the highest thermal eff. > > > > This gives rise to the expression " lean cruise " a trick the > > manufacturers use to artificially raise the fuel economy numbers. > > > > The drive cycle test do not use a speed higher than 92 km/hr so the > > script kiddies at the ECU mapping centers write little algs such as > > > > is vehicle speed 95 km/hr + > > is the engine temp over 65 deg/C > > has the throttle movt. been less than 5% per 10 sec > > is the rate of accel less than 5% > > goto lean burn table > > > > Reason for the table is simple. The A/F ratio is beyond the range of > > that technological slight of hand the oxygen " switch ". > > > > Phil > > > > > > > > -------------------------------------------------------------------------- > -- > > To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the > quotes) > > in the body of a message (not the subject) to majordomo@xxx.org > > > > ---------------------------------------------------------------------------- > To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) > in the body of a message (not the subject) to majordomo@xxx.org - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ End of DIY_EFI Digest V5 #67 **************************** 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".