DIY_EFI Digest Sunday, 7 March 1999 Volume 04 : Number 151 In this issue: TDI Re: AquaMist pump (was: Re: Voltage controller) Re: Which Intake RE: Wher to get ZIFs and EPROMs? Re: injector drivers Fw: DiRT: Why is Magnum's ign coil up front? (Duke 3, UNC 0) Re: injector drivers Re: Tuning SoftWare Re: Wher to get ZIFs and EPROMs? RE: injector drivers RE: Where to get ZIFs and EPROMs? steering modifications steering questions Re: Where to get ZIFs and EPROMs? Re: injector drivers Re: steering questions Re: Which Intake PIC ALDL display Re: Which Intake Re: Which Intake Re: throttle before or after turbo Re: steering modifications Re: Which Intake Re: throttle before or after turbo Re: Which Intake Re: injector drivers Re: injector drivers See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: m.cortecchia@xxx.it (Marco Cortecchia) Date: Sun, 07 Mar 1999 11:46:14 +0100 Subject: TDI Do some one know the algorimt that new BOSCH TDI ECU perform ? It's not a regular CheckSum . Thank MARCO CORTECCHIA ( SoftWare developer ) Via Bellini 70/A 40026 - Imola ( BO ) ITALIA Tel/Fax : +39-(0)542-681936 m.cortecchia@xxx.it www.3wad.com/efi ------------------------------ From: rr Date: Sun, 07 Mar 1999 09:00:26 -0800 Subject: Re: AquaMist pump (was: Re: Voltage controller) Now I got it! I think that you need to do some testing with this unit. If you modulate the control signal at about 4Hz, you can probably do what you want. The reason for this slow, is to still allow the pump to give full cycles. The PWM controller may work for this, it will need to be slowed down. The .1uf cap hangin off pin 2 will need to be made larger in value. Something between 1 & 3.3uf might be enough. As you mention below, you can try to vary the pump volts in order to slow the pump down. But this gets messy with all the heat build up and pump stalling at lower voltages. Let us know what you find... BobR. Daniel Houlton wrote: > > rr wrote: > > > > OK, finally got into this site (it can be reeeaaallll slow). This is > > an interesting pump. Basically, it is a solenoid driven pump. Figure > > a bicycle pump with a magnetic solenoid pulling back the rod, then a > > powerful spring returning the rod to the original position to pump. > > The pump stroke is run at about 50Hz. > > > > There are electronics built into the pump itself, no separate > > controller. > > According to the schematic, the input siganl is just an on/off as the > > water is required. They use a pressure switch. > > > > Bottom line, Dan, I don't think that you need anything else to drive > > this pump. It's all self-contained... > > Yeah it looks that way, but it can still be controlled to vary the > amount of injection by controlling the pressure. The basic system > comes with an on/of pressure switch which means you get all or none. > > Their upper-level kit includes their fuel injector control box which > also has an output for this pump. It increases pump pressure and > therefor the amount of water injected as the boost pressure goes up. > > That's basically what I want to do. Provide a variable voltage signal > (looks like 0 - 12V) to increase water pressure as boost goes up. If > I could get this signal from the 0 - 5V a MAP sensor gives, I can get > a nice water injection curve instead of turning it on full blast at X > psi with a pressure switch. > > Use the pressure switch that comes with the pump to arm the system > and prevent injection before 3 psi say. Then map the MAP output so > that the pump gets about 6V (half pressure) at say 3 psi and then ramps > up rapidly to deliver 12V (full pressure) by 8 or 9 psi. > > Someone mentioned an op-amp could do this. Also a 555. What is a > 555? Is that a particular op-amp? I remember it being referred to as > a timer someone used to drive and additional injector from the signal > to a stock one. > > For now I'll start studying op-amps. Thanks for the help. > > --Dan ------------------------------ From: Frederic Breitwieser Date: Sun, 07 Mar 1999 17:47:20 +0000 Subject: Re: Which Intake > concern is where the throttle blades are located. The turbo will quickly lose > rpm with the blades after the turbo. To counter act that condition a relief But, if you place the throttle blades BEFORE the fresh air side of the turbos, for a few seconds anyway, the turbo will keep pressurizing the plenum while creating a vaccum on the pre-turbo side... thus giving you less throttle reponse when you let up on the gas pedal. Most OEMs, as far as I can tell, place the throttle plates after the turbo, and I copied this on my twin-turbo setup, with two throttle assemblies. - -- Frederic Breitwieser Bridgeport, CT 06606 http://www.xephic.dynip.com 1993 Superchaged Lincoln Continental 1989 500cid Turbocharged HWMMV 1975 Dodge D200 Club Cab (soon to be twin turbo 440) 2000 Buick GTP (twin turbo V6) ------------------------------ From: "Ward Spoonemore" Date: Sun, 7 Mar 1999 11:47:12 -0800 Subject: RE: Wher to get ZIFs and EPROMs? These ECM's clock at 1 mhz, that's 1000 ns, I don't think you could find chips that are to slow, most likely they would be more noise susceptible is the they are too fast. Ward. - -----Original Message----- From: owner-diy_efi@xxx.edu [mailto:owner-diy_efi@xxx.edu]On Behalf Of ECMnut@xxx.com Sent: Saturday, March 06, 1999 8:29 PM To: diy_efi@xxx.edu Subject: Re: Wher to get ZIFs and EPROMs? Bob, I have had problems with 'some' 250ns chips in my 7749 ecm. I got a prom error and it went into limp mode. I think he should use 200 or faster. On the other hand, I may have had some duds. Mike V > > These are National Semiconductor 256's, CMOS, quartz windows, at > 250ns access. They are pulls that I purchased from Astro Marketing. > If these will do, $1 @xxx. > > I'm posting this so that maybe someone can help as to the access time, > I don't know if these are correct for Ted's application. > ------------------------------ From: "John Dammeyer" Date: Sun, 7 Mar 1999 12:59:29 -0800 Subject: Re: injector drivers Hi All, I'm building a ignition/injection system for a Honda 1595 CC engine. So far the CD ignition works great as do all the appropriate sensors like the MAP/Air Temperature etc. I'm wondering how to go about handling the Throttle Position Sensor. ie: While the engine is in a steady state condition the combination of MAP and Barometric Pressure sensors along with RPM determine the initial injector pulse width. The O2 sensor closes the loop. Now if the throttle is opened suddenly I know I need to increase the pulse width. I can: 1) just use a timer to increase the mixture to 10:1 for a preprogrammed time. This simulates the accelerator pump on a carburated engine. 2) Increase the mixture to 10:1 until the ratio between MAP and Barometer reach some set point. 3) Do both. What I don't want happening is a too rich mixture once the throttle is wide open and the engine is loaded at some RPM that no longer increases. Would I be best to use the rate of change of the RPM as an indicator to back off on the Pulse Width? What do the commercial injection systems do? Comments? Thanks, John ------------------------------ From: "Jim Yeagley" Date: Sun, 7 Mar 1999 15:49:00 -0500 Subject: Fw: DiRT: Why is Magnum's ign coil up front? (Duke 3, UNC 0) Thought this might be a good question for this list... - -----Original Message----- From: Henry LaViers To: dirt@xxx.com> Date: Sunday, March 07, 1999 2:26 PM Subject: DiRT: Why is Magnum's ign coil up front? (Duke 3, UNC 0) > Got to thinking while checking the oil this morning: > >Why is the ignition coil on the Magnum engines all the way at the front of >the engine when the distributor is at the back? > >It makes the low voltage primary wires and high voltage coil wire extra >long - and by running the length of the passenger side engine bank - may >create the crossfire problem with the other plug wires. > >The coil is mounted to the engine - which may give it a good ground - but >shakes it with every revolution of the crank. > >Having the coil there puts it near the breeze from the radiator fan, but it >is getting hot air since it is getting wht has passed through the radiator. > >It is even on the wrong side of the engine if they were trying to keep it - >and it's EMI producing wires - away from the PCM computer. > >I know the speed of light is fast, but I wonder if re-locating the coil to >near the distributor would "advance" the timing just a bit - since the >coil's inductance would not have to 'charge' the parasitic capacitance of a >long wire prior to each plug firing. > >My father has the theory that the distributor is at the back - in a hard to >work on place- to protect it from water splashed through the radiator when >fording streams - part of the Dodge 'military' heritage. > >Any ideas on why the ignition coil is up front ? > >-Hank > >Duke just beat UNC for the third time this season ! >Hank's three favorite teams: >Duke, Kentucky, anyteam playing UNC. > > > > >=========================================================== >This list courtesy of Off-Road.Com: http://www.off-road.com/dodge > > ------------------------------ From: "Clarence L.Snyder" Date: Sun, 07 Mar 1999 16:15:58 -0500 Subject: Re: injector drivers > While the engine is in a steady state condition the combination of > MAP and Barometric Pressure sensors along with RPM determine the initial > injector pulse width. The O2 sensor closes the loop. Now if the > throttle is opened suddenly I know I need to increase the pulse width. > This may be a real "rube", but try this on for size. Hook up a small DC motor as a generator with a rack and pinion drive connected to the throttle. Rectify the output so it is uni-polar (only reads when positive) and use a positive output from this device to add an additional pulse, or lengthen the pulse on the injectors. As long as the foot is going down there will be a signal, which richens the mix. When you reach equilibrium, the pulse goes back to normal. The MAP will compensate for the extra load pretty well by itself, and the extra enrichment from this device would be automatic and self limiting. A detonation sensor could be connected to the same circuit to richen the mixture under "ping" conditions. ------------------------------ From: yaron sadot Date: Sun, 07 Mar 1999 11:22:13 +0200 Subject: Re: Tuning SoftWare hey! would u happen to know about mp3.1 bosch on alfa 33? yaron Marco Cortecchia wrote: > Hi, > My name is Marco Cortecchia , I'm a Mechanincal Engineering student in > Bologna's University . My work is SoftWare developing for Mechanical > engineerieng and ECU&CHIP tuning . I just write the release 2.0 of my > SoftWare Eprom Wizard . It's a general pourpose SoftWare for ECU tuning and > it can manage the new 16 bit Racelogic EPROM Emulator ( with realtime > changes and Trace ) . > > If You are interest , You can visit my Web site : > > www.3wad.com/efi/ > > I'm ready to reply to Your questions . > > Best Regards > MARCO CORTECCHIA ( SoftWare developer ) > Via Bellini 70/A > 40026 - Imola ( BO ) ITALIA > > Tel/Fax : +39-(0)542-681936 > m.cortecchia@xxx.it > www.3wad.com/efi ------------------------------ From: "Bruce Plecan" Date: Sun, 7 Mar 1999 17:06:07 -0500 Subject: Re: Wher to get ZIFs and EPROMs? - ----Original Message----- From: Ward Spoonemore To: diy_efi@xxx.edu> Date: Sunday, March 07, 1999 2:57 PM Subject: RE: Wher to get ZIFs and EPROMs? I though the P-4 were at 5-6 Mhz?. Bruce >These ECM's clock at 1 mhz, that's 1000 ns, I don't think you could find >chips that are to slow, most likely they would be more noise susceptible is >the they are too fast. >Ward. > >-----Original Message----- >From: owner-diy_efi@xxx.edu >[mailto:owner-diy_efi@xxx.edu]On Behalf Of >ECMnut@xxx.com >Sent: Saturday, March 06, 1999 8:29 PM >To: diy_efi@xxx.edu >Subject: Re: Wher to get ZIFs and EPROMs? > > >Bob, >I have had problems with 'some' 250ns chips in my 7749 ecm. >I got a prom error and it went into limp mode. I think he should >use 200 or faster. On the other hand, I may have had some duds. >Mike V >> >> These are National Semiconductor 256's, CMOS, quartz windows, at >> 250ns access. They are pulls that I purchased from Astro Marketing. >> If these will do, $1 @xxx. >> >> I'm posting this so that maybe someone can help as to the access time, >> I don't know if these are correct for Ted's application. >> > ------------------------------ From: Jemison Richard Date: Sun, 7 Mar 1999 17:13:37 -0500 Subject: RE: injector drivers John, How about some details of your design - maybe some parameters, example maps? Also, the ignition system. Are you able to advance completely electronically or do you still depend on a mechanical advance system - to any extent? Catch me offline if you'd rather. Sounds great! rick jemisonr@xxx.com > -----Original Message----- > From: John Dammeyer [SMTP:johnd@xxx.com] > Sent: Sunday, March 07, 1999 3:59 PM > To: diy_efi@xxx.edu > Subject: Re: injector drivers > > Hi All, > > I'm building a ignition/injection system for a Honda 1595 CC engine. So > far the CD ignition works great as do all the appropriate sensors like > the MAP/Air Temperature etc. I'm wondering how to go about handling the > Throttle Position Sensor. > > ie: While the engine is in a steady state condition the combination of > MAP and Barometric Pressure sensors along with RPM determine the initial > injector pulse width. The O2 sensor closes the loop. Now if the > throttle is opened suddenly I know I need to increase the pulse width. > > I can: > > 1) just use a timer to increase the mixture to 10:1 for a preprogrammed > time. This simulates the accelerator pump on a carburated engine. > > 2) Increase the mixture to 10:1 until the ratio between MAP and > Barometer reach some set point. > > 3) Do both. > > What I don't want happening is a too rich mixture once the throttle is > wide open and the engine is loaded at some RPM that no longer increases. > > Would I be best to use the rate of change of the RPM as an indicator to > back off on the Pulse Width? > > What do the commercial injection systems do? > > Comments? > > Thanks, > > John ------------------------------ From: "Ward Spoonemore" Date: Sun, 7 Mar 1999 14:58:21 -0800 Subject: RE: Where to get ZIFs and EPROMs? No, the actual clock speed is xtal/4, this puts the p6 and p66's at a tad over 2 mHZ. or 500ns. Pretty slow huh. Ward - -----Original Message----- From: owner-diy_efi@xxx.edu [mailto:owner-diy_efi@xxx.edu]On Behalf Of Bruce Plecan Sent: Sunday, March 07, 1999 2:06 PM To: diy_efi@xxx.edu Subject: Re: Wher to get ZIFs and EPROMs? - ----Original Message----- From: Ward Spoonemore To: diy_efi@xxx.edu> Date: Sunday, March 07, 1999 2:57 PM Subject: RE: Wher to get ZIFs and EPROMs? I though the P-4 were at 5-6 Mhz?. Bruce >These ECM's clock at 1 mhz, that's 1000 ns, I don't think you could find >chips that are to slow, most likely they would be more noise susceptible is >the they are too fast. >Ward. > >-----Original Message----- >From: owner-diy_efi@xxx.edu >[mailto:owner-diy_efi@xxx.edu]On Behalf Of >ECMnut@xxx.com >Sent: Saturday, March 06, 1999 8:29 PM >To: diy_efi@xxx.edu >Subject: Re: Wher to get ZIFs and EPROMs? > > >Bob, >I have had problems with 'some' 250ns chips in my 7749 ecm. >I got a prom error and it went into limp mode. I think he should >use 200 or faster. On the other hand, I may have had some duds. >Mike V >> >> These are National Semiconductor 256's, CMOS, quartz windows, at >> 250ns access. They are pulls that I purchased from Astro Marketing. >> If these will do, $1 @xxx. >> >> I'm posting this so that maybe someone can help as to the access time, >> I don't know if these are correct for Ted's application. >> > ------------------------------ From: James Weiler Date: Sun, 7 Mar 1999 15:21:12 -0800 (PST) Subject: steering modifications I have some suspension and steering modifications I'd like to make to my '69 Cougar (same as a '69 Mustang). Can anybody direct me to a different mailing list q ------------------------------ From: James Weiler Date: Sun, 7 Mar 1999 15:22:27 -0800 (PST) Subject: steering questions Sorry guys I meant to delete that message not send it, but I hit the wrong quick key. Sorry to chew up your band width. jw ------------------------------ From: "Bruce Plecan" Date: Sun, 7 Mar 1999 18:36:21 -0500 Subject: Re: Where to get ZIFs and EPROMs? - -----Original Message----- From: Ward Spoonemore To: diy_efi@xxx.edu> Date: Sunday, March 07, 1999 6:17 PM Subject: RE: Where to get ZIFs and EPROMs? Faster and more accurate then my pen+pad thou. Thanks for those masks, at that URL. Wound up referencing the .bins I have by ecm+mask no.. Almost can find stuff now!!. Thanks Bruce >No, the actual clock speed is xtal/4, this puts the p6 and p66's at a tad >over 2 mHZ. or 500ns. Pretty slow huh. >Ward > >-----Original Message----- >From: owner-diy_efi@xxx.edu >[mailto:owner-diy_efi@xxx.edu]On Behalf Of Bruce >Plecan >Sent: Sunday, March 07, 1999 2:06 PM >To: diy_efi@xxx.edu >Subject: Re: Wher to get ZIFs and EPROMs? > > >----Original Message----- >From: Ward Spoonemore >To: diy_efi@xxx.edu> >Date: Sunday, March 07, 1999 2:57 PM >Subject: RE: Wher to get ZIFs and EPROMs? > >I though the P-4 were at 5-6 Mhz?. >Bruce > > >>These ECM's clock at 1 mhz, that's 1000 ns, I don't think you could find >>chips that are to slow, most likely they would be more noise susceptible is >>the they are too fast. >>Ward. >> >>-----Original Message----- >>From: owner-diy_efi@xxx.edu >>[mailto:owner-diy_efi@xxx.edu]On Behalf Of >>ECMnut@xxx.com >>Sent: Saturday, March 06, 1999 8:29 PM >>To: diy_efi@xxx.edu >>Subject: Re: Wher to get ZIFs and EPROMs? >> >> >>Bob, >>I have had problems with 'some' 250ns chips in my 7749 ecm. >>I got a prom error and it went into limp mode. I think he should >>use 200 or faster. On the other hand, I may have had some duds. >>Mike V >>> >>> These are National Semiconductor 256's, CMOS, quartz windows, at >>> 250ns access. They are pulls that I purchased from Astro Marketing. >>> If these will do, $1 @xxx. >>> >>> I'm posting this so that maybe someone can help as to the access time, >>> I don't know if these are correct for Ted's application. >>> >> > ------------------------------ From: "Bruce Plecan" Date: Sun, 7 Mar 1999 19:04:05 -0500 Subject: Re: injector drivers - -----Original Message----- From: John Dammeyer To: diy_efi@xxx.edu> Date: Sunday, March 07, 1999 4:52 PM Subject: Re: injector drivers Delta TPS, and Delta MAP, both corrected by coolant temp., are common. Bruce >I'm building a ignition/injection system for a Honda 1595 CC engine. So >far the CD ignition works great as do all the appropriate sensors like >the MAP/Air Temperature etc. I'm wondering how to go about handling the >Throttle Position Sensor. > >ie: While the engine is in a steady state condition the combination of >MAP and Barometric Pressure sensors along with RPM determine the initial >injector pulse width. The O2 sensor closes the loop. Now if the >throttle is opened suddenly I know I need to increase the pulse width. > >I can: > >1) just use a timer to increase the mixture to 10:1 for a preprogrammed >time. This simulates the accelerator pump on a carburated engine. > >2) Increase the mixture to 10:1 until the ratio between MAP and >Barometer reach some set point. > >3) Do both. > >What I don't want happening is a too rich mixture once the throttle is >wide open and the engine is loaded at some RPM that no longer increases. > >Would I be best to use the rate of change of the RPM as an indicator to >back off on the Pulse Width? > >What do the commercial injection systems do? > >Comments? > >Thanks, > >John > ------------------------------ From: Frederic Breitwieser Date: Mon, 08 Mar 1999 00:12:51 +0000 Subject: Re: steering questions > Sorry guys I meant to delete that message not send it, but I hit the FORDNATICS - -- Frederic Breitwieser Bridgeport, CT 06606 http://www.xephic.dynip.com 1993 Superchaged Lincoln Continental 1989 500cid Turbocharged HWMMV 1975 Dodge D200 Club Cab (soon to be twin turbo 440) 2000 Buick GTP (twin turbo V6) ------------------------------ From: DC Smith Date: Sun, 07 Mar 1999 19:00:05 -0600 Subject: Re: Which Intake Frederic Breitwieser wrote: > > > concern is where the throttle blades are located. The turbo will quickly lose > > rpm with the blades after the turbo. To counter act that condition a relief > > But, if you place the throttle blades BEFORE the fresh air > side of the turbos, for a few seconds anyway, the turbo will > keep pressurizing the plenum while creating a vaccum on the > pre-turbo side... thus giving you less throttle reponse when > you let up on the gas pedal. Don't you want less throttle response when you let up? (sorry, Fred.. couldn't help it on that one) Vacuum is good. > Most OEMs, as far as I can > tell, place the throttle plates after the turbo, and I > copied this on my twin-turbo setup, with two throttle > assemblies. I can't vouch for what most OEM's did or didn't do, but I can tell ya what GM did on the Buicks. (I know the carbed cars had it before the turbo) The 84/5 non-intercooled turbo cars had the throttle body before the turbo. Maybe it's just me, but I feel that the vacuum caused when closing the throttle quickly, is actually is easier on the turbo than the "fart" caused when hammering the throttle shut, with the TB after the turbo . (such as my car does now) I do feel that the non-intercooled car's turbo's lasted longer, due to this design. No air (vacuum) = nothing to hammer the bearings. No matter what way it's done, they both have their advantages / disadvantages on different buildups. Either way works quite well. IMO :) *********************************************************************** Dan Smith 84 Regal 12.13@112 GSCA# 1459 St.Charles, Missouri mailto:dcsmith@xxx.net mailto:dcsmith@xxx.org mailto:morepoweral@xxx.net mailto:morepoweral@xxx.org mailto:morepoweral@xxx.net mailto:smithd@xxx.com http://www.tetranet.net/users/morepoweral *********************************************************************** ------------------------------ From: Niinikoski Juha Date: Mon, 8 Mar 1999 03:07:36 +0200 Subject: PIC ALDL display Just got my first Internet pages up and running. Pages are still very preliminary but you can find something about my PIC16F84 ALDL display project from there. In next few days I am going to uppload HC12 project stuff and some pictures there. http://www.geocities.com/MotorCity/Factory/6113/ Juha ------------------------------ From: WLundquist@xxx.com Date: Sun, 7 Mar 1999 20:26:44 EST Subject: Re: Which Intake I am in agreement with Dan, on the issue of location, what is the application of your car? In the world challenge series we had a big problem with turbo lag do to the throttle being located after the turbo, the drivers had to simultaneously feather the throttle when braking to keep the boost up so that they weren't left behind coming out of the corners. I had suggested putting a vacuum operated dump valve in the intake runner between the turbo and the throttle but it was never tried, something the stock Eagles had. Allowing the turbo to spin in a vacuum after closing the throttle means instant boost when the throttle is nailed. Refer to TURBOCHARGERS by Hugh Macinnes. TIA Wayne ------------------------------ From: AL8001@xxx.com Date: Sun, 7 Mar 1999 20:37:38 EST Subject: Re: Which Intake In a message dated 99-03-07 12:59:45 EST, frederic.breitwieser@xxx.com writes: > >But, if you place the throttle blades BEFORE the fresh air >side of the turbos, for a few seconds anyway, the turbo will >keep pressurizing the plenum while creating a vaccum on the >pre-turbo side... thus giving you less throttle reponse when >you let up on the gas pedal. Most OEMs, as far as I can >tell, place the throttle plates after the turbo, and I >copied this on my twin-turbo setup, with two throttle >assemblies. > > >-- >Frederic Breitwieser Early Chrysler 2.2 turbo cars had the throttle body on the inlet side of the turbo. Later cars had the throttle body on the outlet side. Anyone have or has driven both? A tbody on the inlet side would produce a vaccume during light throttle openings. This would tend to draw oil past the turbo seal. If the tbody is after the turbo, the compressor seal would only see boost or atmospheric pressure. I agree with FB's above reply. Though a after turbo tbody system should have a blowoff valve between the turbo and the tbody. This relieves pressure when the throttle is snaped shut, reducing stress in the turbo and allowing the compressor stay at speed. SAAB/ Mitsubishi and others use this valve. Harold ------------------------------ From: Chris Conlon Date: Sun, 07 Mar 1999 21:00:42 -0500 Subject: Re: throttle before or after turbo At 12:32 PM 3/6/99 EST, WLundquist@xxx.com wrote: >A better alternative is to put the tb's before the turbo inlet >so that when the tb's are closed the turbo will spin in a vacuum and maintain >rpm, this will make for guicker recovery when you stab the throttle. Frederic mentioned poor trailing-throttle response as a possible drawback to this approach... I personally don't believe that, for various reasons, but the thing I do worry about is having lots of oil sucked into the air in the turbo. How much of a problem is this, really? I know some turbo vendors have special sealing options avilable, but I'd like to hear from people who have set any old turbo up with the TB before it, if you had much problem with sucking oil into the intake. The only reason I care this week is a weird turn of events has led to the possibility that I'll get a turbo'ed car soon, and I'd like to know, if I move the throttle before the turbo, how much trouble am I asking for? Yeah I could get a new turbo/upgrade it/etc, but for various reasons I would not like to have to do that. TIA, Chris C. ------------------------------ From: Mark Romans Date: Sun, 07 Mar 1999 19:14:10 -0800 Subject: Re: steering modifications http://merchant.calweb.com/business3/business3/totalcontrolproducts/ Awesome Ford stuff. They said they are developing GM stuff too. Mark - -----Original Message----- From: James Weiler To: diy_efi@xxx.edu> Date: Sunday, March 07, 1999 3:25 PM Subject: steering modifications > >I have some suspension and steering modifications I'd like to make to my '69 >Cougar (same as a '69 Mustang). Can anybody direct me to a different >mailing list q > ------------------------------ From: bearbvd@xxx.net (Greg Hermann) Date: Sun, 7 Mar 1999 20:29:54 -0700 Subject: Re: Which Intake >Frederic Breitwieser wrote: >> >> > concern is where the throttle blades are located. The turbo will >>quickly lose >> > rpm with the blades after the turbo. To counter act that condition a >>relief >> >> But, if you place the throttle blades BEFORE the fresh air >> side of the turbos, for a few seconds anyway, the turbo will >> keep pressurizing the plenum while creating a vaccum on the >> pre-turbo side... thus giving you less throttle reponse when >> you let up on the gas pedal. > > > Don't you want less throttle response when you let up? (sorry, Fred.. >couldn't help it on that one) Vacuum is good. > >> Most OEMs, as far as I can >> tell, place the throttle plates after the turbo, and I >> copied this on my twin-turbo setup, with two throttle >> assemblies. > > I can't vouch for what most OEM's did or didn't do, but I can tell ya >what GM did on the Buicks. (I know the carbed cars had it before the >turbo) The 84/5 non-intercooled turbo cars had the throttle body before >the turbo. Maybe it's just me, but I feel that the vacuum caused when >closing the throttle quickly, is actually is easier on the turbo than >the "fart" caused when hammering the throttle shut, with the TB after >the turbo . (such as my car does now) I do feel that the non-intercooled >car's turbo's lasted longer, due to this design. No air (vacuum) = >nothing to hammer the bearings. > No matter what way it's done, they both have their advantages / >disadvantages on different buildups. > Either way works quite well. IMO :) Hi Dan-- No question here that a draw through throttle set up will give you better spool up from a turbo, shut-down lag is negligible, although a bit more than with a blow through. You do need the premium compressor seal in a draw through turbo. I SUSPECT that the main reason why most mfgrs go with blow through set-ups is because of the length of the emissons warranty they must meet--lose a compressor seal, and the impact on emissions is VERY distinct and immediate! Also, with a properly sized compressor, their is NO WAY you ever put your compressor into surge with a draw through set up. Nor, contrary to popular old wive's tales, are you in any danger of overspeeding your turbo under vacuum conditions. (To verify this statement, look at how turbos behave on aero engines at higher altitudes.) As far as I am concerned for a custom turbo set-up, draw through is the superior way to go UNLESS you are using a VATN type turbo. If I ever get around to figuring out a way to control the variable turbine vanes on a VATN while running one of them in the draw through mode, I would be highly inclined to use them that way too! Regards, Greg > > >*********************************************************************** >Dan Smith 84 Regal 12.13@112 GSCA# 1459 >St.Charles, Missouri >mailto:dcsmith@xxx.net >mailto:dcsmith@xxx.org >mailto:morepoweral@xxx.net >mailto:morepoweral@xxx.org >mailto:morepoweral@xxx.net >mailto:smithd@xxx.com >http://www.tetranet.net/users/morepoweral >*********************************************************************** ------------------------------ From: "Gary Derian" Date: Sun, 7 Mar 1999 22:08:59 -0500 Subject: Re: throttle before or after turbo Old style carbureted turbos with draw thru carbs had decent throttle response but the volume of the intake was small, carb, turbo, manifold with no intercoolers, etc. If you have a high performance turbo with high boost and an intercooler, lots of plumbing, etc, you definitly need to have the throttle after the turbo. In that case, you also need a valve to prevent surging the turbo when closing the throttle after a high rpm run, say a shift. Gary Derian >At 12:32 PM 3/6/99 EST, WLundquist@xxx.com wrote: > >>A better alternative is to put the tb's before the turbo inlet >>so that when the tb's are closed the turbo will spin in a vacuum and maintain >>rpm, this will make for guicker recovery when you stab the throttle. > >Frederic mentioned poor trailing-throttle response as a possible drawback >to this approach... I personally don't believe that, for various >reasons, but the thing I do worry about is having lots of oil sucked >into the air in the turbo. How much of a problem is this, really? I >know some turbo vendors have special sealing options avilable, but I'd >like to hear from people who have set any old turbo up with the TB >before it, if you had much problem with sucking oil into the intake. > >The only reason I care this week is a weird turn of events has led >to the possibility that I'll get a turbo'ed car soon, and I'd like to >know, if I move the throttle before the turbo, how much trouble am >I asking for? Yeah I could get a new turbo/upgrade it/etc, but for >various reasons I would not like to have to do that. > > TIA, > Chris C. ------------------------------ From: bearbvd@xxx.net (Greg Hermann) Date: Sun, 7 Mar 1999 20:50:45 -0700 Subject: Re: Which Intake >I am in agreement with Dan, on the issue of location, what is the application >of your car? >In the world challenge series we had a big problem with turbo lag do to the >throttle being located after the turbo, the drivers had to simultaneously >feather the throttle when braking to keep the boost up so that they weren't >left behind coming out of the corners. I had suggested putting a vacuum >operated dump valve in the intake runner between the turbo and the throttle >but it was never tried, something the stock Eagles had. The old Accel draw thru carb turbo adapter kits had this feature--they called it a "priority valve"--twenty years ago. Regards, Greg Allowing the turbo to >spin in a vacuum after closing the throttle means instant boost when the >throttle is nailed. Refer to TURBOCHARGERS by Hugh Macinnes. > TIA > Wayne ------------------------------ From: "John Dammeyer" Date: Sun, 7 Mar 1999 20:30:26 -0800 Subject: Re: injector drivers Definitely a 'rube' when determining delta TPS in software is trivial. Thanks for the idea though. John - -----Original Message----- From: Clarence L.Snyder To: diy_efi@xxx.edu Date: Sunday, March 07, 1999 2:08 PM Subject: Re: injector drivers >> While the engine is in a steady state condition the combination of >> MAP and Barometric Pressure sensors along with RPM determine the initial >> injector pulse width. The O2 sensor closes the loop. Now if the >> throttle is opened suddenly I know I need to increase the pulse width. >> >This may be a real "rube", but try this on for size. Hook up a small DC >motor as a generator with a rack and pinion drive connected to the >throttle. Rectify the output so it is uni-polar (only reads when >positive) and use a positive output from this device to add an >additional pulse, or lengthen the pulse on the injectors. As long as the >foot is going down there will be a signal, which richens the mix. When >you reach equilibrium, the pulse goes back to normal. The MAP will >compensate for the extra load pretty well by itself, and the extra >enrichment from this device would be automatic and self limiting. >A detonation sensor could be connected to the same circuit to richen the >mixture under "ping" conditions. > ------------------------------ From: "John Dammeyer" Date: Sun, 7 Mar 1999 20:06:03 -0800 Subject: Re: injector drivers - -----Original Message----- From: Jemison Richard To: 'diy_efi@xxx.edu' Date: Sunday, March 07, 1999 3:06 PM Subject: RE: injector drivers >John, > >How about some details of your design - maybe some parameters, example maps? >Also, the ignition system. Are you able to advance completely >electronically or do you still depend on a mechanical advance system - to >any extent? Catch me offline if you'd rather. Sounds great! > Yes, I advance completely electronically. I use grey code for determining which of the four quadrants I am in on the camshaft. The unit has a CAN bus so I spit out the engine parameters to a PC via CAN and then display on a PC the entire instrument panel using Delphi and ActiveX. I have a circular gauge that has 720 degrees and a set of coloured anular rings representing Intake valve open, Exhaust valve open, the needle shows advance and a third red ring shows the injector pulse width. Under low pulse widths it sits nicely under the blue intake valve portion starting inection about 5 degrees after the intake starts to open. As the engine speeds up the red ring creeps in the same direction until about 5 degrees before the intake valve closes. After that the open time shifts earlier and earlier into the engine cycle. At RPM's under 4000 there is no intake/exhaust overlap. At 4000 RPM the indication that the VTEC solonoid has been activated arrives and so the two anular rings that show valve timing change to show that now there is exhaust/intake overlap. I run stock injectors at 80% duty cycle. The ignition is High Energy Capacitive Discharge and produces a decent spark even at 8V battery voltage. It's really quite fascinating to watch. As the engine speeds up the valve and ignition timing changes graphically on the PC screen. I have a linear gauge that shows the O2 sensor and it tracks mixture nicely. Overall, thanks to information from Bruce Bowling, Al Grippo, a series of articles in Circuit Cellar Ink by Ed Lansinger along with all sorts miscellaneous application notes from Siemens and Philips Semi. the system is coming along nicely. Hopefully, we'll be testing injection on the dyno this week. So far, with an Alison mechanical fuel injection throttle body the ignition has allowed the engine to produce 130HP at maxium RPM. And we know that the Alison doesn't provide an even mixture to the cylinders. Cheers, John >rick >jemisonr@xxx.com > >> -----Original Message----- >> From: John Dammeyer [SMTP:johnd@xxx.com] >> Sent: Sunday, March 07, 1999 3:59 PM >> To: diy_efi@xxx.edu >> Subject: Re: injector drivers >> >> Hi All, >> >> I'm building a ignition/injection system for a Honda 1595 CC engine. So >> far the CD ignition works great as do all the appropriate sensors like >> the MAP/Air Temperature etc. I'm wondering how to go about handling the >> Throttle Position Sensor. >> >> ie: While the engine is in a steady state condition the combination of >> MAP and Barometric Pressure sensors along with RPM determine the initial >> injector pulse width. The O2 sensor closes the loop. Now if the >> throttle is opened suddenly I know I need to increase the pulse width. >> >> I can: >> >> 1) just use a timer to increase the mixture to 10:1 for a preprogrammed >> time. This simulates the accelerator pump on a carburated engine. >> >> 2) Increase the mixture to 10:1 until the ratio between MAP and >> Barometer reach some set point. >> >> 3) Do both. >> >> What I don't want happening is a too rich mixture once the throttle is >> wide open and the engine is loaded at some RPM that no longer increases. >> >> Would I be best to use the rate of change of the RPM as an indicator to >> back off on the Pulse Width? >> >> What do the commercial injection systems do? >> >> Comments? >> >> Thanks, >> >> John > ------------------------------ End of DIY_EFI Digest V4 #151 ***************************** 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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