DIY_EFI Digest Wednesday, 24 February 1999 Volume 04 : Number 128 In this issue: Plasma Jet Ignition injector size and bin questions RE: Plasma Jet Ignition Re: injector size and bin questions Re: injector size and bin questions Re: injector size and bin questions Re: Engine Control Question RE: injector size and bin questions Re: ECM wiring harness help RE: injector size and bin questions Re: Re: Engine Control Question Re: ECM wiring harness help TH-400 help Re: TH-400 help Re: Plasma Jet Ignition/TIG setup Re: Re: Engine Control Question RE: EGR Correction Question Re: TH-400 help Re: Plasma Jet Ignition Re: TH-400 help wanted: aftermarket efi box RE: injector size and bin questions RE: ECM wiring harness help Re: Plasma Jet Ignition Saginaw fittings RE: TH-400 help See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: bob@xxx.com (Robert Harris) Date: Tue, 23 Feb 1999 16:42:27 GMT Subject: Plasma Jet Ignition More Heywood Factoids - chapter 9.5 All spark ignition is divided into three stages: Breakdown, arc and glow. Breakdown is when the spark is first established, arc is after the plasma explosion and glow is the termination of spark. The breakdown stage is where the plasma column is generated. Its characterizes by high (> 10 KV) voltage, high peak current (~200 A) and short duration (~10 ns ) and is about 40 micro m in diameter. All energy is transferred without loss to this column. The temperature and pressure rise extremely rapidly in this column to about 60,000 k and a few hundred atmospheres. A strong shock wave or blast wave propagates outward, the channel expands and in consequence, the plasma temperature falls. Typically, 30% of the plasma energy is carried away by the shock wave: however most of this is regained since spherical blast waves transfer most of their energy to the gas within a small sphere (~ 2mm) into which the breakdown plasma soon expands. The breakdown phase ends when a hot spot develops on the cathode and the column degrades to an arc. The arc phase voltage is low (< 100v), though the current can be as high as the external circuit permits. In contrast to the breakdown phase where the gas in the channel is fully disassociated and ionized, in the arc phase the degrees of disassociation may still be high at the center of the discharge, but the degree of ionization is much lower (~ 1%). Voltage drops at the cathode and anode electrodes are a significant fraction of the arc voltage and the energy deposited in these electrode sheath regions, which is conducted away by the metal electrodes, is a substantial fraction of the total energy. About 94% of the spark energy is converted to plasma in the breakdown phase vs only 50% in the arc stage - plus the arc stage is only ~6000K. About .2mj of energy is required to ignite a quiescent stoichiometric fuel-air mixture at normal engine conditions. Swirl, turbulence, etc raise this number by an order of magnitude in a working normal engine. Conventional coil type ignitions deliver 30 to 50 MJ, but a plasma jet typically requires 1 joule or more stored energy and this is released in < 20 microseconds. There is a race condition - to pump as much energy as fast as possible into the plasma column after it is established and before the plasma blast so as to maximize the blast effect. Before the blast and cathode hot spotting occurs, the plasma column has almost infinite conductance. Since greater than 90% of the pumped energy will convert to plasma at sun like temperatures in the breakdown stage, its critical to pump it early. The blast wave from the plasma chamber into the main chamber is comparable to trying to light a pool of gasoline with a match ( conventional ) or a blow torch ( Plasma Jet ) 1963 Ford C-600 Prison Bus Conversion "Home" 1971 Lincoln Continental 460 "Christine" 1972 "Whale" Mustang awaiting transplant 1978 Dodge Long Bed Peeek Up "Bundymobile" Habaneros - not just for breakfast anymore ------------------------------ From: Doug Mansfield Date: Tue, 23 Feb 1999 12:57:30 -0500 Subject: injector size and bin questions First fuel injector size: What conditions are fuel injectors rated under. If it is rated for 35lbs/hr, what fuel pressure and air pressure are these rated at? Binaries: Do the rom dumps from the GM ECMs contain both the "program" and the "data"? Thanks Doug ------------------------------ From: Don.F.Broadus@xxx.com Date: Tue, 23 Feb 1999 12:12:47 -0600 Subject: RE: Plasma Jet Ignition Smokey yunick of racing fame experimented with the plasma ignition and found the results promising. The power supply was the biggest problem to overcome to get plasma out of the lab and onto the street. You mention lighting gas with a blowtorch, Smokey actually did that and that's what got him started on plasma experiments. > -----Original Message----- > From: bob@xxx.com] > Sent: Tuesday, February 23, 1999 10:42 AM > To: diy_efi@xxx.com > Subject: Plasma Jet Ignition > > More Heywood Factoids - chapter 9.5 > > All spark ignition is divided into three stages: Breakdown, arc and glow. > Breakdown is when the spark is first established, arc is after the plasma > explosion and glow is the termination of spark. > > The breakdown stage is where the plasma column is generated. Its > characterizes > by high (> 10 KV) voltage, high peak current (~200 A) and short duration > (~10 > ns ) and is about 40 micro m in diameter. All energy is transferred > without > loss to this column. The temperature and pressure rise extremely rapidly > in > this column to about 60,000 k and a few hundred atmospheres. A strong > shock > wave or blast wave propagates outward, the channel expands and in > consequence, > the plasma temperature falls. Typically, 30% of the plasma energy is > carried > away by the shock wave: however most of this is regained since spherical > blast > waves transfer most of their energy to the gas within a small sphere (~ > 2mm) > into which the breakdown plasma soon expands. > > The breakdown phase ends when a hot spot develops on the cathode and the > column degrades to an arc. > > The arc phase voltage is low (< 100v), though the current can be as high > as > the external circuit permits. In contrast to the breakdown phase where > the > gas in the channel is fully disassociated and ionized, in the arc phase > the > degrees of disassociation may still be high at the center of the > discharge, > but the degree of ionization is much lower (~ 1%). Voltage drops at the > cathode and anode electrodes are a significant fraction of the arc > voltage > and the energy deposited in these electrode sheath regions, which is > conducted > away by the metal electrodes, is a substantial fraction of the total > energy. > > About 94% of the spark energy is converted to plasma in the breakdown > phase > vs only 50% in the arc stage - plus the arc stage is only ~6000K. > > About .2mj of energy is required to ignite a quiescent stoichiometric > fuel-air > mixture at normal engine conditions. Swirl, turbulence, etc raise this > number > by an order of magnitude in a working normal engine. > > Conventional coil type ignitions deliver 30 to 50 MJ, but a plasma jet > typically requires 1 joule or more stored energy and this is released in > < 20 > microseconds. > > There is a race condition - to pump as much energy as fast as possible > into > the plasma column after it is established and before the plasma blast so > as to > maximize the blast effect. Before the blast and cathode hot spotting > occurs, > the plasma column has almost infinite conductance. Since greater than 90% > of > the pumped energy will convert to plasma at sun like temperatures in the > breakdown stage, its critical to pump it early. > > The blast wave from the plasma chamber into the main chamber is comparable > to > trying to light a pool of gasoline with a match ( conventional ) or a blow > torch ( Plasma Jet ) > > 1963 Ford C-600 Prison Bus Conversion "Home" > 1971 Lincoln Continental 460 "Christine" > 1972 "Whale" Mustang awaiting transplant > 1978 Dodge Long Bed Peeek Up "Bundymobile" > > Habaneros - not just for breakfast anymore ------------------------------ From: Roger Heflin Date: Tue, 23 Feb 1999 12:17:42 -0600 (CST) Subject: Re: injector size and bin questions On Tue, 23 Feb 1999, Doug Mansfield wrote: > > First fuel injector size: > > What conditions are fuel injectors rated under. If it is rated for > 35lbs/hr, what fuel pressure and air pressure are these rated at? > The answer is it varies. Each manufactures seems to rate them under slightly different fuel pressure. I think they all use air pressure as the outside pressure, and realisticly there is not going to be a big flow difference between the lowest and highest air pressure. Probably not enough to even matter. > > Binaries: > > Do the rom dumps from the GM ECMs contain both the "program" and the "data"? > Generally yes, mine (93 Lt1 in a Z28) has 0x8000 is data, 0x9000 is blank (extra potential data mabye?), and 0xA000-0xFFFF is program (0x0000 on the 32kB rom maps to 0x8000). On some of the bigger newer ECMS I have heard that there are often several proms, and with some even having 2 or more computers. I am pretty sure mine also has a ABS computer, but I don't know where it is, or if it even has a removable prom. Roger > > Thanks > > Doug > ------------------------------ From: "Bruce Plecan" Date: Tue, 23 Feb 1999 13:28:45 -0500 Subject: Re: injector size and bin questions - -----Original Message----- From: Doug Mansfield To: Do-it-Yourself Fuel Injection Mailing List Date: Tuesday, February 23, 1999 1:06 PM Subject: injector size and bin questions >First fuel injector size: >What conditions are fuel injectors rated under. If it is rated for >35lbs/hr, what fuel pressure and air pressure are these rated at? There are no absolute standards, varies by manufacturer > >Binaries: > >Do the rom dumps from the GM ECMs contain both the "program" and the "data"? On cars with memcals, or flash, yes. ruce > >Thanks >Doug ------------------------------ From: bearbvd@xxx.net (Greg Hermann) Date: Tue, 23 Feb 1999 11:57:31 -0700 Subject: Re: injector size and bin questions >First fuel injector size: > >What conditions are fuel injectors rated under. If it is rated for >35lbs/hr, what fuel pressure and air pressure are these rated at? Generally at 3 bar--43.5 psi pressure DIFFERENCE across the injector from fuel rail to manifold. However , some injectors are rated at slightly different pressures. Also-- They are usually rated based on their flow at an 85% duty cycle: Flow is measured at 85% duty cycle, then multiplied by 1/.85 to arrive at the rated flow. Greg >Thanks > >Doug ------------------------------ From: Chris Morriss Date: Tue, 23 Feb 1999 19:35:48 +0000 Subject: Re: Engine Control Question In message <000001be5ee8$74366ca0$02000003@xxx.net>, Scott Feaver writes >I have been monitoring my engine with diacom and have found out a few things >about it.. One of which leaves me wondering why... > >Here are the details >91 Sunbird >3.1L V6 Engine >Automatic, 2.53 Axle > >When speeding up from a dead stop at WOT, the fuel injector pulse width is >around 12.2ms. Once it goes above 3700 rpm or so, it starts to slowly >decline until it hits 5200 (right before shifting). At 5200 rpm the pulse >width is 9.8ms. Why would this be? Is this so the engine doesn't melt :), >or for emissions reasons. If this stayed at 12.2ms right to the shiftpoint, >would this generate more power? > >Also, this thing has the 730 ECM. How many frames per second on this baby? >(I asked this before, but now know exactly what to specify :) Has anyone >found out anything about the MEMCALs for this ECM? I have the eeprom loaded >in if anyone wants to take a look.. > >Thanks, >Scott > I would guess that the peak torque rpm for you engine is at 3700rpm. Above that figure your volumetric efficiency will be falling off, so that there will be less air drawn into each cylinder on the induction stroke. The pulse width will be decreased to keep the air/fuel ratio correct. - -- Chris Morriss ------------------------------ From: "Van Setten, Tim (AZ75)" Date: Tue, 23 Feb 1999 13:15:01 -0700 Subject: RE: injector size and bin questions > >What conditions are fuel injectors rated under. If it is rated for > >35lbs/hr, what fuel pressure and air pressure are these rated at? > My question is what specfic gravity of fuel are "They" using as a standard and what are "They" using for the weight of the fuel? I have seen some using anywhere from 5.5 lb to 6 lb. per gal. > Also-- They are usually rated based on their flow at an 85% duty cycle: > Flow is measured at 85% duty cycle, then multiplied by 1/.85 to arrive at > the rated flow. > Sorry, I have to ask why would you flow an injector at 85%, then multiply by .85??? Wouldn't it be easier to flow it at 100% then multiply by 85%? Tim ------------------------------ From: steve ravet Date: Tue, 23 Feb 1999 15:28:50 -0600 Subject: Re: ECM wiring harness help Bill, is '97 an OBD-II ECM? If so you might think about using the electronics from a '96 or earlier. The further back you go the cheaper it is likely to be. Carsonwv@xxx.com wrote: > > Well, I bought a 97 4.3L Vortech to put into a CJ-7 or an older S-10. I am > having difficulty locating a wiring harness for it though. Getting a computer > for it is easy enough. Junk yard wants $80 - $100 for one. The junk yards I > have called want $200 - $300 for the wiring harness though. Would anyone know > where I could find an inexpensive wiring harness? Better yet anyone know > where I can get all of the connectors to make my own? > > Another question I have is do I really need a MAF sensor when it already has a > MAP sensor? Unfortunately it did not come with this sensor and I am too cheap > to buy one. I have worked on a lot of cars with one or the other, but not > both. I noticed that the newer cars are using both. I assume for > emmisions...??? > > Thanks. > Bill Carson - -- Steve Ravet steve.ravet@xxx.com Advanced Risc Machines, Inc. www.arm.com ------------------------------ From: bearbvd@xxx.net (Greg Hermann) Date: Tue, 23 Feb 1999 15:07:15 -0700 Subject: RE: injector size and bin questions >> >What conditions are fuel injectors rated under. If it is rated for >> >35lbs/hr, what fuel pressure and air pressure are these rated at? >> > My question is what specfic gravity of fuel are "They" using as a >standard and what are "They" using for the weight of the fuel? I have seen >some using anywhere from 5.5 lb to 6 lb. per gal. I think Stoddard solvent is the usual testing fluid, more like 6.5 #/gallon, .78 Sp. grav. Again, this may vary from one mfgr and/or injector to another. > >> Also-- They are usually rated based on their flow at an 85% duty cycle: >> Flow is measured at 85% duty cycle, then multiplied by 1/.85 to arrive at >> the rated flow. >> >Sorry, I have to ask why would you flow an injector at 85%, then multiply by >.85??? Wouldn't it be easier to flow it at 100% then multiply by 85%? >Tim You lose the effect on flow of the opening and closing transients on the flow if it is just tested wide open. Greg ------------------------------ From: ECMnut@xxx.com Date: Tue, 23 Feb 1999 18:02:21 EST Subject: Re: Re: Engine Control Question Working from memory here, but at 5000 RPM, I think you have less than 13ms between intake events with a 4 stroke engine. I'm wondering what calc is taking place to give you the numbers you mentioned. Your time window decreases as RPM increases.. Does anyone have the formula? I'm not where I can scan the archives. Mike V <<>When speeding up from a dead stop at WOT, the fuel injector pulse width is >around 12.2ms. Once it goes above 3700 rpm or so, it starts to slowly >decline until it hits 5200 (right before shifting). At 5200 rpm the pulse >width is 9.8ms. Why would this be? Is this so the engine doesn't melt :), >or for emissions reasons. If this stayed at 12.2ms right to the shiftpoint, >would this generate more power? > >Also, this thing has the 730 ECM. How many frames per second on this baby? >(I asked this before, but now know exactly what to specify :) Has anyone >found out anything about the MEMCALs for this ECM? I have the eeprom loaded >in if anyone wants to take a look.. >>> ------------------------------ From: andy quaas Date: Tue, 23 Feb 1999 15:24:54 -0800 (PST) Subject: Re: ECM wiring harness help Call howell-efi (www.howell-efi.com). They were selling complete intake setups with harness and computer for like $1250 or so. They were brand new pulls from some defective 4.3s. I am sure that they would make you a harness with whatever computer you wanted (prolly 96 or so). Andy p.s. you have to look through everything on their website to get their phone number. - ---steve ravet wrote: > > Bill, is '97 an OBD-II ECM? If so you might think about using the > electronics from a '96 or earlier. The further back you go the cheaper > it is likely to be. > > Carsonwv@xxx.com wrote: > > > > Well, I bought a 97 4.3L Vortech to put into a CJ-7 or an older S-10. I am > > having difficulty locating a wiring harness for it though. Getting a computer > > for it is easy enough. Junk yard wants $80 - $100 for one. The junk yards I > > have called want $200 - $300 for the wiring harness though. Would anyone know > > where I could find an inexpensive wiring harness? Better yet anyone know > > where I can get all of the connectors to make my own? > > > > Another question I have is do I really need a MAF sensor when it already has a > > MAP sensor? Unfortunately it did not come with this sensor and I am too cheap > > to buy one. I have worked on a lot of cars with one or the other, but not > > both. I noticed that the newer cars are using both. I assume for > > emmisions...??? > > > > Thanks. > > Bill Carson > > -- > Steve Ravet > steve.ravet@xxx.com > Advanced Risc Machines, Inc. > www.arm.com > _________________________________________________________ DO YOU YAHOO!? Get your free @xxx.com ------------------------------ From: "Jennifer and Brock Fraser" Date: Tue, 23 Feb 1999 18:27:59 -0600 Subject: TH-400 help Possibly someone can help me with a TH-400 application. I haven't ever had any dealings with these units, so I have a few questions... 1. The trans has a wire labeled "kickdown switch". What does this do, and do you ground it or supply +12 to activate it? (I assume +12v, since there are no other wires and grounding could be through the case) 2. Does anyone see any problems with deleting the speedo sensor, since the speedometer on my car takes its reading from the differential, and I'll be using a manual transmission calibration with the PCM... (96 LT1) I think the only thing that a manual cal uses the speedo for is idle speed, and I can do without that. Error codes aren't a concern... 3. There's a modulator on the side of the case. What does a modulator do when it sees boost pressure? Should I use a check valve to block boost from going to it? 4. How do you adjust the wide open throttle shift points? I realize that the trans must be disassembled. Thanks a lot, Brock ------------------------------ From: AL8001@xxx.com Date: Tue, 23 Feb 1999 20:05:37 EST Subject: Re: TH-400 help In a message dated 99-02-23 19:40:30 EST, you write: >Possibly someone can help me with a TH-400 application. I haven't ever had >any dealings with these units, so I have a few questions... > >1. The trans has a wire labeled "kickdown switch". What does this do, and >do you ground it or supply +12 to activate it? (I assume +12v, since there >are no other wires and grounding could be through the case) This wire is connected to a solenoid valve. It drops the trans from third to second gear when the throttle is over ~85%. Possibly to first as well, but I'm not sure. Just add 12V to operate, the solenoid grounds through the case. A 400 with two wires has a pressure sensor to detect third gear ( for emissions spark retard) or it's a mid '60s switch pitch trans. >2. Does anyone see any problems with deleting the speedo sensor, since the >speedometer on my car takes its reading from the differential, and I'll be >using a manual transmission calibration with the PCM... (96 LT1) I think >the only thing that a manual cal uses the speedo for is idle speed, and I >can do without that. Error codes aren't a concern... Speedo Sensor? Are you refering to the speedo cable port/ gear on the side of the trans? If so, not a problem. Just use a freeze plug or a block off plate from a 4 wd truck. >3. There's a modulator on the side of the case. What does a modulator do >when it sees boost pressure? Should I use a check valve to block boost from >going to it? > A 400 uses the modulator to generate throttle pressure and vary line pressure. With limits, high line pressure at boost would be good. Higher throttle presure _may_ make the trans shift too late under boost. Not sure if a check valve would help. >4. How do you adjust the wide open throttle shift points? I realize that >the trans must be disassembled. WOT shift points 1-2 and 2-3 can be moved upwards and downwards by changing govenor weights and springs. Just take the four bolt cover off the side of the trans to remove the gov. You may need to have the trans on a slight down grade to prevent fluid loss. B & M sells the spring and weight kit. To change the spaceing between the 1-2 and the 2-3 shift, the valve body must be removed and the 1-2 or the 2-3 shift valve springs changed. For the shift kits I've seen, none alter the spaceing between the 1-2 and the 2-3 shift. All concentrate on quick shifts and highter line pressure. >Thanks a lot, >Brock Harold ------------------------------ From: Chad Clendening Date: Tue, 23 Feb 1999 19:21:32 -0600 Subject: Re: Plasma Jet Ignition/TIG setup I took at the guts of a 175 amp Lincoln TIG. It appears to use a series transformer to put the high frequency on top of the AC / DC source for welding. It has a circuit board about a foot by a foot with a portion of the circuitry siliconed over to control everything. This unit had several SCR's or triac's, don't know exactly what they are used for. Chad Clarence L.Snyder wrote: > Tony Bryant wrote: > > > > > bob@xxx.com (Robert Harris) wrote: > > > > > > >Re-reading my Heywood and have become re-in-love with the concept of > > > >plasma jet ignition. Essentially, a normal CD ignition fires the > > > >plug in a cavity connected to the main chamber by an orifice. Once > > > >the arc is established, a second low voltage high current capacitive > > > >discharge is routed into the arc. > > > > > > Hey - I like the sound of THAT. Did someone get this working? > > > > > > This reminds me of the arc stabilizers you find on TIG welders - a high > > > frequencyt current starts the pilot plasma/arc which then allows the > > > main welding current to flow on through... > > > > > > > I've also been toying with this idea for a while, but I can't see how > > you can connect a HV, LC and a LV, HC source together. The > > seemingly inevitble problem is the LVHC source must be low > > impedence, and therefore absorbs the HV in preference the spark > > gap? How are these TIG welders arranged? > > Something called a DIODE, I think. Actually on the TIGs it may be an > SCR. ------------------------------ From: bearbvd@xxx.net (Greg Hermann) Date: Tue, 23 Feb 1999 18:27:44 -0700 Subject: Re: Re: Engine Control Question >Working from memory here, but at 5000 RPM, > I think you have less than 13ms between intake events >with a 4 stroke engine. Times 2!! Closer to 24ms per cycle at 5000rpm on a FOUR stroke. I'm wondering what calc is >taking place to give you the numbers you mentioned. >Your time window decreases as RPM increases.. >Does anyone have the formula? >I'm not where I can scan the archives. >Mike V > ><<>When speeding up from a dead stop at WOT, the fuel injector pulse width is >>around 12.2ms. Once it goes above 3700 rpm or so, it starts to slowly >>decline until it hits 5200 (right before shifting). At 5200 rpm the pulse >>width is 9.8ms. Why would this be? Is this so the engine doesn't melt :), >>or for emissions reasons. If this stayed at 12.2ms right to the shiftpoint, >>would this generate more power? >> >>Also, this thing has the 730 ECM. How many frames per second on this baby? >>(I asked this before, but now know exactly what to specify :) Has anyone >>found out anything about the MEMCALs for this ECM? I have the eeprom loaded >>in if anyone wants to take a look.. >>>> ------------------------------ From: "Ward Spoonemore" Date: Tue, 23 Feb 1999 17:44:23 -0800 Subject: RE: EGR Correction Question No guessing, Ok look at the 1227747 caib in the case of say ARGU calibration, Generally fuel out during EGR in proportion to amount of EGR, some small amount of spark added. Look for your self. The EGR spark table is at $D146 th $D156, and the 3D EGR fuel table is at at $D324 th $D36D Ward > -----Original Message----- > From: owner-diy_efi@xxx.edu > [mailto:owner-diy_efi@xxx.edu]On Behalf Of Bruce > Plecan > Sent: Monday, February 22, 1999 3:03 PM > To: DIY_EFI > Subject: EGR Correction Question > > > Does anyone know of a GM calibration that takes timing out, or reduces > the amount of fuel during EGR apply. > > As it apprears to me it's always, add timing, and add fuel. > > Please no quessing...... > Thanks > Bruce > ------------------------------ From: Tom Sharpe Date: Tue, 23 Feb 1999 20:07:13 -0600 Subject: Re: TH-400 help Jennifer and Brock Fraser wrote: > Possibly someone can help me with a TH-400 application. I haven't ever had > any dealings with these units, so I have a few questions... > > 1. The trans has a wire labeled "kickdown switch". What does this do, and > do you ground it or supply +12 to activate it? (I assume +12v, since there > are no other wires and grounding could be through the case) Forces the trans into second gear. (+12) > 2. Does anyone see any problems with deleting the speedo sensor, since the > speedometer on my car takes its reading from the differential, and I'll be > using a manual transmission calibration with the PCM... (96 LT1) I think > the only thing that a manual cal uses the speedo for is idle speed, and I > can do without that. Error codes aren't a concern... OK. > 3. There's a modulator on the side of the case. What does a modulator do > when it sees boost pressure? Should I use a check valve to block boost from > going to it? It tells the trans MAP for shift point determination and raises internal pressure to eliminate slipping.Only if it blows out!!! (yes) > 4. How do you adjust the wide open throttle shift points? I realize that > the trans must be disassembled. Change the governor weights/springs. Get a kit from TCI for the whole trans. > Regards Tom S > Thanks a lot, > Brock ------------------------------ From: "Jeffrey T. Birt" Date: Tue, 23 Feb 1999 20:17:43 -0600 Subject: Re: Plasma Jet Ignition This plasma jet thread has been interesting. I repair welders and plasma cutting machines for a living so perhaps I can shed some light on the subject. By no mean do I profess to be an expert though. First the TIG welder question. Typically this is arc starting capability is called 'High Frequency' in the welding world. It is really very simple. One of the welding leads passes through the center of an air core transformer. A high voltage, high frequency signal is 'superimposed' (transformer coupled actually) on the weld voltage. This 'high freq.' lets you establish the arc without touching the work piece. As for the plasma thing. The initial high voltage low current arc is called the pilot arc. It sort of serves the same purpose as in the TIG application. As to the application to a plasma gas ignition? I don't know. Just remember an arc exist point to point, i.e. across a gap. Jeff Birt > bob@xxx.com (Robert Harris) wrote: > > >Re-reading my Heywood and have become re-in-love with the concept of > >plasma jet ignition. Essentially, a normal CD ignition fires the > >plug in a cavity connected to the main chamber by an orifice. Once > >the arc is established, a second low voltage high current capacitive > >discharge is routed into the arc. > > Hey - I like the sound of THAT. Did someone get this working? > > This reminds me of the arc stabilizers you find on TIG welders - a high > frequencyt current starts the pilot plasma/arc which then allows the > main welding current to flow on through... > > Keep me advised as to your success! :) > -Bill > > ______________________________________________________ > Get Your Private, Free Email at http://www.hotmail.com ------------------------------ From: Shannen Durphey Date: Tue, 23 Feb 1999 21:42:58 -0500 Subject: Re: TH-400 help Possibly someone can :) Jennifer and Brock Fraser wrote: > > Possibly someone can help me with a TH-400 application. I haven't ever had > any dealings with these units, so I have a few questions... > > 1. The trans has a wire labeled "kickdown switch". What does this do, and > do you ground it or supply +12 to activate it? (I assume +12v, since there > are no other wires and grounding could be through the case) When you step on the throttle, it closes a switch supplying 12V to the downshift solenoid. You get downshift. Like the kickdown cable on other trans'. > > 2. Does anyone see any problems with deleting the speedo sensor, since the > speedometer on my car takes its reading from the differential, and I'll be > using a manual transmission calibration with the PCM... (96 LT1) I think > the only thing that a manual cal uses the speedo for is idle speed, and I > can do without that. Error codes aren't a concern... > Deleting? Leaving disconnected, no. Removing it and leaving a gaping hole, yes. > 3. There's a modulator on the side of the case. What does a modulator do > when it sees boost pressure? Should I use a check valve to block boost from > going to it? > Modulator adjusts line pressure to make shifts harder/softer with more/less load. Also plays a part in determining which gear trans downshifts to when throttle is stomped, and upshift points. If you use a check valve, the line to the modulator needs to be vented so vacuum isn't trapped in the line. Also, they make plugs to replace the modulator. You might investigate this route. > 4. How do you adjust the wide open throttle shift points? I realize that > the trans must be disassembled. Modulator + governor springs. Look for a "Shift Kit" by TransGo, there's goodies + good info there, and price is right. No substitutions, either. Also try to get A1 Trans or B+M catalogues. I can dig out some phone #'s for these guys tomorrow. > > Thanks a lot, > Brock No problem. Shannen ------------------------------ From: Michael Kent Date: Tue, 23 Feb 1999 20:06:33 -0800 (PST) Subject: wanted: aftermarket efi box I need a QUICK solution to a long standing problem with a buddies project car. Looking for an aftermarket efi box w/ software, could be DFI, TECII, Haltech, whatever. You got it, I want it. thanx, MK ------------------------------ From: "Ward Spoonemore" Date: Tue, 23 Feb 1999 20:09:29 -0800 Subject: RE: injector size and bin questions Injectors may be rated several ways, generally static flow and dynamic. Static is full on, dynamic is cycled at various duty cycles. Fuel pressure is up to the maker, but often is 3 bar, (3x barometric) or 3 x 14.7 PSI. Ward - -----Original Message----- From: owner-diy_efi@xxx.edu [mailto:owner-diy_efi@xxx.edu]On Behalf Of Doug Mansfield Sent: Tuesday, February 23, 1999 9:58 AM To: Do-it-Yourself Fuel Injection Mailing List Subject: injector size and bin questions First fuel injector size: What conditions are fuel injectors rated under. If it is rated for 35lbs/hr, what fuel pressure and air pressure are these rated at? Binaries: Do the rom dumps from the GM ECMs contain both the "program" and the "data"? Thanks Doug ------------------------------ From: "Ward Spoonemore" Date: Tue, 23 Feb 1999 20:15:14 -0800 Subject: RE: ECM wiring harness help MY 1999, 5.7l vortech is running swell on a 1227747 ECM in my 1990 p/u, its a lot easer to deal with as a converion. Ward - -----Original Message----- From: owner-diy_efi@xxx.edu [mailto:owner-diy_efi@xxx.edu]On Behalf Of steve ravet Sent: Tuesday, February 23, 1999 1:29 PM To: diy_efi@xxx.edu Subject: Re: ECM wiring harness help Bill, is '97 an OBD-II ECM? If so you might think about using the electronics from a '96 or earlier. The further back you go the cheaper it is likely to be. Carsonwv@xxx.com wrote: > > Well, I bought a 97 4.3L Vortech to put into a CJ-7 or an older S-10. I am > having difficulty locating a wiring harness for it though. Getting a computer > for it is easy enough. Junk yard wants $80 - $100 for one. The junk yards I > have called want $200 - $300 for the wiring harness though. Would anyone know > where I could find an inexpensive wiring harness? Better yet anyone know > where I can get all of the connectors to make my own? > > Another question I have is do I really need a MAF sensor when it already has a > MAP sensor? Unfortunately it did not come with this sensor and I am too cheap > to buy one. I have worked on a lot of cars with one or the other, but not > both. I noticed that the newer cars are using both. I assume for > emmisions...??? > > Thanks. > Bill Carson - -- Steve Ravet steve.ravet@xxx.com Advanced Risc Machines, Inc. www.arm.com ------------------------------ From: Raymond C Drouillard Date: Mon, 22 Feb 1999 23:33:05 -0500 Subject: Re: Plasma Jet Ignition >Conventional coil type ignitions deliver 30 to 50 MJ, but a plasma jet >typically requires 1 joule or more stored energy and this is released in < 20 >microseconds. At one joule per zap, we're talking about feeding 400 watts into the plasma plugs of a V8 running at 6000 RPM. 6000 Rev/min * (1 min/60 sec) * 4 sparks/rev * 1 joule/spark = 400 W (or about 25 W / cylinder) How efficient can we make the circuit that charges the capaciter? Even if it's VERY efficient, it's going to suck down a significent fraction of the output of a typical alternater. Of course, it'll only do that at high RPMs. I think it would be best to design it so that each cylinder has its own capaciter, charger, etc. I wouldn't try to feed all of this energy through the dizzy gap. Lesee... we'll assume that we're going to charge the cap to 200 V. E = .5 * C * V^2 (if I remember correctly <:-) ) That gives use a capacitence of 50 microfarads. A flash capaciter ought to do the trick. How fast do we want to rev the engine? Let's say, for example, 12,000 RPM (and we can downgrade it for more ordinary applications). That's one zap every 0.01 sec. If we want to charge the capaciter in eight milliseconds with one joule of energy, we'll need a converter that can feed the capaciter at an average rate of about 125 Watts. Remember, though, that the output of this circuit will be high current/low voltage at first. The voltage will go up and the current will go down as the capaciter charges. I'm not trying to throw bricks at the idea. I would like to try it. I just wanted to rough out some design parameters so that we'll know what we're dealing with. For one thing, we need to consider how much spare capacity is in the vehicle's alternater. This thing might end up sucking down 30 A or so at cruising RPM. Will the increase in BSHP make up for the increased drag on the engine? We essentially need an ordinary ignition system coupled with the circuitry from a high speed xenon strobe. Anyone wanna try taking apart a high-speed timing light? (JK) Maybe we can feed the arc current through the secondary. The main problems will be the inductance of the coil and the coil's ability to handle the high current. Running it through an HV diode stack will also cause trouble. The forward breakdown voltage of an HV stack is in the neighborhood of 100 V. That'll dissapate a lot of the power that we want to go to the arc. A more practical solution might be to have seperate HV and LV electrodes that are very close to each other. This could be tricky. How can we design the electrodes so that the LV circuitry won't absorb the energy from the HV trigger. I'll have to ruminate on this one for a while. Ray Drouillard ___________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com/getjuno.html or call Juno at (800) 654-JUNO [654-5866] ------------------------------ From: "Fran and Bud" Date: Tue, 23 Feb 1999 21:02:55 +0000 Subject: Saginaw fittings Does anyone know of a source of "Saginaw to hose barb" or "Saginaw to AN" fittings at less than $10 each ?? My local NAPA has good high pressure fuel filters at under $10 but most of them have female Saginaw inlet/outlet but no source for fittings. Any suggestions for low cost, high pressure, fuel filters with either hose barbs or 45 degree SAE inlet/outlet fittings?? Thanks, Bud ------------------------------ From: Marc Piccioni Date: Tue, 23 Feb 1999 22:16:27 -0700 Subject: RE: TH-400 help I can answer 3 of your questions, see below - ---------- From: Jennifer and Brock Fraser[SMTP:fraser@xxx.com] Sent: February 23, 1999 5:27 PM To: diy_efi@xxx.edu Subject: TH-400 help Possibly someone can help me with a TH-400 application. I haven't ever had any dealings with these units, so I have a few questions... 1. The trans has a wire labeled "kickdown switch". What does this do, and do you ground it or supply +12 to activate it? (I assume +12v, since there are no other wires and grounding could be through the case) This applies +12 volts to the kickdown solenoid inside the transmission valve body and forces a "kickdown" shift to the next lowest gear. The switch to activate it should be set up to close at 90% of WOT. 2. Does anyone see any problems with deleting the speedo sensor, since the speedometer on my car takes its reading from the differential, and I'll be using a manual transmission calibration with the PCM... (96 LT1) I think the only thing that a manual cal uses the speedo for is idle speed, and I can do without that. Error codes aren't a concern... 3. There's a modulator on the side of the case. What does a modulator do when it sees boost pressure? Should I use a check valve to block boost from going to it? If you are going positive pressure YES. The modulator regulates the line pressure to control the shift firmness and to a degree shift points. 4. How do you adjust the wide open throttle shift points? I realize that the trans must be disassembled. WOT shift points are controlled by a combination of govenor weight/springs and 1-2, 2-3 valve body spring. Suggest you get a book "How to rebuild and modify your Turbo 400", excellent book. If you have never rebuild a automatic before you may wish to get help. There are a lot of places to "miss". 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