DIY_EFI Digest Monday, March 6 2000 Volume 05 : Number 087 In this issue: RE: anti-lag system Turbo speed sensor ever used ? RE: anti-lag system RE: anti-lag system Re: Turbo speed sensor ever used ? Re: Turbo speed sensor ever used ? Re: ECT and voltage divider help? Re: ECT and voltage divider help? Re: Turbo speed sensor ever used ? Re: Turbo speed sensor ever used ? Re: Turbo speed sensor ever used ? Re: Turbo speed sensor ever used ? OEM Black box alterations Re: Turbo speed sensor ever used ? Re: Turbo speed sensor ever used ? Re: Turbo speed sensor ever used ? Re: anti-lag system Subaru TBI RE: attn: help needed Re: Turbo speed sensor ever used ? See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Sat, 4 Mar 2000 11:12:23 -0500 From: Dylan Johnson Subject: RE: anti-lag system What if you injected H2O into the exhaust manifold to create steam? Would the expanding steam drive the turbine? - ---------------------------------------------------------------------------- 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: Mon, 06 Mar 2000 21:57:59 From: "Mike (Perth, WA)" Subject: Turbo speed sensor ever used ? HI chaps, Wonder if anyone has considered using a turbo speed sensor in any capacity to augment EFI controller inputs ? I can understand it might be more efficient to have a separate boost controller - I'm interested if anyone has already made any optical tacho setup on the inlet ie. reflect infra red of blades, count pulses, apply formula to output shaft speed as data log qty or suitable for display etc ? Rgds :) mike - ---------------------------------------------------------------------------- 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: Mon, 06 Mar 2000 22:21:18 From: "Mike (Perth, WA)" Subject: RE: anti-lag system At 11:12 AM 4/03/2000 -0500, you wrote: >What if you injected H2O into the exhaust manifold to create steam? >Would the expanding steam drive the turbine? Yes, this is what I've heard is possible, though I fear that too much might overspeed the turbine (hence my last query about turbine speed) and too little (in the wrong place) might just stress the turbine/manifold without resulting in much spinup, (when its needed), I suppose the best point of injection would be some point before the turbo - so the water has a chance to turn into steam in the distance available - this is assuming of course it starts out as water. Given the exh manifold runs way above boiling usually then the water either has to be at higher pressure or the valve for injection needs to be far enough away so there is liquid water ie. Max use of water to steam expansion where possible before hitting the turbine, or does it actually matter ? Then of course there'd need to be some transient detect so the water only comes on during 'sudden' throttle open and when the turbo is at slow speed and doesn't turn up at other times with problematic results. Tah :) mike - ---------------------------------------------------------------------------- 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: Mon, 6 Mar 2000 07:07:52 -0700 From: bearbvd@xxx.net (Greg Hermann) Subject: RE: anti-lag system >What if you injected H2O into the exhaust manifold to create steam? >Would the expanding steam drive the turbine? H2O in the exhaust manifold has a similar effect to using a smaller A/R ratio turbine housing. At lower engine speeds, it will improve turbine performance. As you approach the ideal operating flow for the turbine housing which is being used, the water will hinder performance. Bottom line--the water is some help if done right, but a hindrance if NOT done right. Coating and/or insulating the exhaust manifold will have more of a positive effect. Remember--it is HEAT ENERGY in the exhaust gasses which drives the turbine. The more heat you keep in the exhaust gas prior to the turbine, the more efficiently the turbine will operate. (Hotter gas going through the turbine=lower absolute pressure ratio across the turbine for the same power output--thus less back pressure on the motor, and more power output at the same boost level. Greg - ---------------------------------------------------------------------------- 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: Mon, 6 Mar 2000 07:09:53 -0700 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: Turbo speed sensor ever used ? >HI chaps, > >Wonder if anyone has considered using a turbo speed sensor in any capacity >to augment EFI controller inputs ? > >I can understand it might be more efficient to have a separate boost >controller - I'm interested if anyone has already made any optical tacho >setup on the inlet ie. reflect infra red of blades, count pulses, apply >formula to output shaft speed as data log qty or suitable for display etc ? > >Rgds > >:) mike > Yes, it's been done. Mostly appropriate when pushing a turbo to the ragged limits of compression pressure ratio. Greg - ---------------------------------------------------------------------------- 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: Mon, 06 Mar 2000 23:00:33 From: "Mike (Perth, WA)" Subject: Re: Turbo speed sensor ever used ? At 07:09 AM 6/03/2000 -0700, you wrote: >Yes, it's been done. Mostly appropriate when pushing a turbo to the ragged >limits of compression pressure ratio. Yeah tah, do you mean as a commercial product or hobby kit or by anyone on this group ? I'm particularly interested in the sensor physical arrangement, the rest I think I would like to do - so looking for any diagrams/pics of the setup ? Tah :) mike - ---------------------------------------------------------------------------- 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: Mon, 06 Mar 2000 10:43:05 -0600 From: "Robert W. Hughes" Subject: Re: ECT and voltage divider help? You might look at the Maxim MAX6510 family. Temperature switch with built in sensor, selectable hysteresis, and temp selection with an external resistor. Only problem might be packaging. They have other versions with remote sensors, but not some of the other neat features. Also I have a circuit which monitors the voltage across the GM temperature gauge sensor and has adjustable turn-on and hysteresis. Uses one comparator and one mosfet or two if you want air conditioner turn-on. I can post this on incoming if there is any interest, although it does not inject any fuel. - -- Robert W. Hughes (Bob) BackYard Engineering 29:40.237N, 95:28.726W Houston, Texas rwhughe@xxx.net - ---------------------------------------------------------------------------- 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: Mon, 6 Mar 2000 10:51:35 -0800 From: "Cudabob" Subject: Re: ECT and voltage divider help? >So, my question is, how do I switch something based on this >voltage? Basically, I want to monitor the voltage to the ECT >sensor and when it drops to around .4 or .5 V I want to trigger an >output (that eventually drives a relay). Then, while the output >is triggered and the voltage I must have missed something, aftermarket fan kits use a thermal switch for control. Quick and easy, what's the objection, or reason to design a circuit? CudaBob '65 - Angels Camp, Calif CudaBob@xxx.com http://www.goldrush.com/~rhuish/ - ---------------------------------------------------------------------------- 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: Mon, 6 Mar 2000 12:05:24 -0700 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: Turbo speed sensor ever used ? >At 07:09 AM 6/03/2000 -0700, you wrote: > >>Yes, it's been done. Mostly appropriate when pushing a turbo to the ragged >>limits of compression pressure ratio. > >Yeah tah, do you mean as a commercial product or hobby kit or by >anyone on this group ? > >I'm particularly interested in the sensor physical arrangement, the rest I >think I would like to do - so looking for any diagrams/pics of the setup ? > >Tah > >:) mike Lee Performance in Lake Elsinore, CA, lists it as an option for $$$$$. They are a US based dealer for your Autronics ecu's--so maybe try Ray Hall Turbocharging @xxx.au> Greg > >---------------------------------------------------------------------------- >To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) >in the body of a message (not the subject) to majordomo@xxx.org - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Mon, 6 Mar 2000 11:29:00 -0800 (PST) From: Clay B Subject: Re: Turbo speed sensor ever used ? During my search for parts, I had occasion to speak with the folks at Richard Lee Performance. Their prices are, to put it mildly, extortionist. Unless you are independently wealthy, I suggest purchasing from a more reasonably priced source. Ray Hall is a good suggestion. - - Clay On Mon, 6 Mar 2000, Greg Hermann wrote: > >At 07:09 AM 6/03/2000 -0700, you wrote: > > > >>Yes, it's been done. Mostly appropriate when pushing a turbo to the ragged > >>limits of compression pressure ratio. > Lee Performance in Lake Elsinore, CA, lists it as an option for $$$$$. They > are a US based dealer for your Autronics ecu's--so maybe try Ray Hall > Turbocharging @xxx.au> > > Greg - ---------------------------------------------------------------------------- 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: Mon, 6 Mar 2000 20:39:13 +0100 From: "Espen Hilde" Subject: Re: Turbo speed sensor ever used ? Hi! I think its very strange that any form of turbocharger rpm or measuring backpressure in a turbo application is not more used in cars. A changing backpressure ,depending on the rpm on turbocharger and wastgate, has a great influence on cylinder filling .A map sensor is not aware of whats going on , and air volume measuring is missing the right ignition timing. Boost VS.backpressure is great to know in development stages.Tells the efficency of the turbo used. Spool up creates more backpressure ,more backpressure ,wants less ignition advance. less air consumption .A fast car is living in theese arias all the time . Just some toughts Espen > >Yes, it's been done. Mostly appropriate when pushing a turbo to the ragged > >limits of compression pressure ratio. > > Yeah tah, do you mean as a commercial product or hobby kit or by > anyone on this group ? > > I'm particularly interested in the sensor physical arrangement, the rest I > think I would like to do - so looking for any diagrams/pics of the setup ? > > Tah > > :) mike > > - ---------------------------------------------------------------------------- > 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: Tue, 07 Mar 2000 04:07:00 From: "Mike (Perth, WA)" Subject: Re: Turbo speed sensor ever used ? At 11:29 AM 6/03/2000 -0800, you wrote: > >During my search for parts, I had occasion to speak with the folks at >Richard Lee Performance. > >Their prices are, to put it mildly, extortionist. mmm I suppose the paradign of "if someone really wants one well lets charge heaps" comes to mind - since they are not common items and I don't see any vehicle manufacturer make them >Unless you are independently wealthy, I suggest purchasing from a more >reasonably priced source. Ray Hall is a good suggestion. mmm- Tah, had a look at the site - couldn't see em, have sent an email so I'll see whats up, Rgds Mike >- Clay > >On Mon, 6 Mar 2000, Greg Hermann wrote: > >> >At 07:09 AM 6/03/2000 -0700, you wrote: >> > >> >>Yes, it's been done. Mostly appropriate when pushing a turbo to the ragged >> >>limits of compression pressure ratio. > >> Lee Performance in Lake Elsinore, CA, lists it as an option for $$$$$. They >> are a US based dealer for your Autronics ecu's--so maybe try Ray Hall >> Turbocharging @xxx.au> Rgds Mike Massen Ancient Sufi saying: "Should your God save you from adversity, choose another God" Pictures of site installation at Mendulong near Sipitang, Sabah (Malaysia) for container based RAPS... http://www.wantree.com.au/~erazmus Vehicle modifications on GMH Turbo, twin tyres, possible 175Kw at wheels Preliminary pictures at http://www.wantree.com.au/~erazmus/Twin_tyre_vehicle/ My editorial on twin-tyre opinion and good reference about tyres:- http://www.geocities.com/MotorCity/2195/ttyreopinion.html - ---------------------------------------------------------------------------- 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: Mon, 6 Mar 2000 12:00:44 -0800 From: "Cudabob" Subject: OEM Black box alterations Steve Burgess wrote, 7F00,0000,0000 > I have, against better advice, taken apart the hermetically sealed > ignitor box on my yamaha motorcycle, looking for dip switches, > potentiometers, or any secret method of altering the stock ignition > timing. (I'm one of those people that if they say it can't be done, > I've got to try it on my own and see if I can proove them wrong) > Great fun...always wanted to destroy....take apart that unit. :-) My guess as to what the box contained was a R/C circuit that controlled the trigger point of the output circuit, yielding a fixed rate of advance. My thought was to add a pot in parallel with the timing resistor to change the advance curve. I designed a circuit that was programmable, but my son add multispark as a additional requirement. There additional hardware exceeded the physical space available, so the project came to a halt. Ultimately the plan is to FI the bike and handle the ignition with the ECU. Space is still a problem. 7F00,0000,0000> I tried to describe the circuit as best as I could, but I have drawn > it out if anyone does'nt immediately recognise it's purpose, and > want's or needs to see it, I can attach it to an email to that person, > I don't want to upload pictures to the list, especially since it's not > directly related to efi. > Send me the schematic...it may fit in to what I expected the box to look like. 7F00,0000,0000> Steve CudaBob '65 - Angels Camp, Calif CudaBob@xxx.com http://www.goldrush.com/~rhuish/ - ---------------------------------------------------------------------------- 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: Tue, 07 Mar 2000 04:29:17 From: "Mike (Perth, WA)" Subject: Re: Turbo speed sensor ever used ? At 08:39 PM 6/03/2000 +0100, you wrote: >Hi! >I think its very strange that any form of turbocharger rpm or measuring >backpressure in a turbo application is not more used in cars. Yes wondered that a little, though thought (so far) the use would be negligible, assuming correct operation (and B/w) of other sensors, >A changing backpressure ,depending on the rpm on turbocharger and wastgate, >has a great influence on cylinder filling .A map sensor is not aware of >whats going on , and air volume measuring is missing the right ignition >timing. >Boost VS.backpressure is great to know in development stages.Tells the >efficency >of the turbo used. >Spool up creates more backpressure ,more backpressure ,wants less ignition >advance. >less air consumption .A fast car is living in theese arias all the time . mmm - Interesting, I'd assumed air flow measurement and MAP would be sufficient to determine volume of air entering the chamber. Are you suggesting AFM doesn't give an accurate enough figure due to backpressure at the turbo and that MAP in no way assists this - in the circumstance where we have an AFM and MAP ? Should we have a pressure sensor before and after turbo or just one, surely AFM output would indicate chamber volume as the air can't go anywhere else ? >Just some toughts Yeah sure, what-ever arrives at an improved understanding, tah, I've alwayus wondered what the relationshiup is between boost and less ignition advance - is it simply chamber filling, propensity to ping, or some other presumably non-linear relationship ? even more to think about and "algorithmate" - somewhere, Rgds ~`:o) Mike Massen Trading as "Network Power Systems" and "Network Computers" Perth, Western Australia Ph +61 8 9444 8961 Fx +618 9264 8229 (fax -> email) Products/Personal/Client web area at http://www.wantree.com.au/~erazmus (Current pics - trip to Malaysia to install equipment in jungle power site) Some say there is no magic but, all things begin with thought then it becomes academic, then some poor slob works out a practical way to implement all that theory, this is called Engineering - for most people another form of magic. - ---------------------------------------------------------------------------- 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: Mon, 6 Mar 2000 14:57:03 -0700 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: Turbo speed sensor ever used ? >>Boost VS.backpressure is great to know in development stages.Tells the >>efficency >>of the turbo used. >>Spool up creates more backpressure ,more backpressure ,wants less ignition >>advance. >>less air consumption .A fast car is living in theese arias all the time . > >mmm - Interesting, I'd assumed air flow measurement and MAP would be >sufficient to determine volume of air entering the chamber. Are you >suggesting AFM doesn't give an accurate enough figure due to backpressure >at the turbo and that MAP in no way assists this - in the circumstance >where we have an AFM and MAP ? > >Should we have a pressure sensor before and after turbo or just one, surely >AFM output would indicate chamber volume as the air can't go anywhere else ? > Espen is absolutely right. where you need the back-pressure sensor is between the engine and the turbo. Back pressure on the engine affects cylinder filling and fuel requirements on a turbo motor just as it does on an NA engine. Greg - ---------------------------------------------------------------------------- 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: Tue, 7 Mar 2000 00:10:01 +0100 From: "Espen Hilde" Subject: Re: Turbo speed sensor ever used ? Hi Again! > mmm - Interesting, I'd assumed air flow measurement and MAP would be > sufficient to determine volume of air entering the chamber. Are you > suggesting AFM doesn't give an accurate enough figure due to backpressure > at the turbo and that MAP in no way assists this - in the circumstance > where we have an AFM and MAP ? The AFM dont know the backpressure and therefore the ecu cant predict the right advance....we are wanting to be right on the edge of detonating here....at a 700hp 2l turbo engine 0,5 degree wrong advance at max torque is 40 hp lost. AFM and a MAP sensor on the exhaust could do the trick if the AFM is fast enough. How the algorithm or map for backpressure vs .boost should work beets me....Ignition retard under accleration when backpressure is higher than steady state... Its complex...... Turbo speed VS. engine rpm wot table? A backpressure table of %influens on volumertric filling at wot? Use a valve on the exhaust pipe for adjusting backpressure under dyno runand fill the tables....a hard day work? Different engines responds different to backpressure at different rpms. > > Should we have a pressure sensor before and after turbo or just one, surely Both is better if you have data log and you are then able to see if your exhaust system is up to the job. > AFM output would indicate chamber volume as the air can't go anywhere else ? IF you have a small overlap camshaft. > > >Just some toughts > > Yeah sure, what-ever arrives at an improved understanding, tah, Even more toughts...... Espen > I've alwayus wondered what the relationshiup is between boost and less > ignition advance - is it simply chamber filling, propensity to ping, or > some other presumably non-linear relationship ? Exhaust backpressure is driving the exhaust temp to the roof..more residual hotexhaustgasses .more prone to detonation. > even more to think about and "algorithmate" - somewhere, - ---------------------------------------------------------------------------- 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: Mon, 06 Mar 2000 18:25:22 -0500 From: Seth Subject: Re: anti-lag system I realize that this isn't legal in most racing classes, butI have seen a 2 second shot of N20 wired into the full throttle switch work wonders as anti-lag. That car (280ZX turbo with bigger turbo) would do prodigious burnouts. - -Seth Greg Hermann wrote: > > >What if you injected H2O into the exhaust manifold to create steam? > >Would the expanding steam drive the turbine? > > H2O in the exhaust manifold has a similar effect to using a smaller A/R > ratio turbine housing. At lower engine speeds, it will improve turbine > performance. As you approach the ideal operating flow for the turbine > housing which is being used, the water will hinder performance. Bottom > line--the water is some help if done right, but a hindrance if NOT done > right. > > Coating and/or insulating the exhaust manifold will have more of a positive > effect. Remember--it is HEAT ENERGY in the exhaust gasses which drives the > turbine. The more heat you keep in the exhaust gas prior to the turbine, > the more efficiently the turbine will operate. (Hotter gas going through > the turbine=lower absolute pressure ratio across the turbine for the same > power output--thus less back pressure on the motor, and more power output > at the same boost level. > > Greg > > ---------------------------------------------------------------------------- > 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: Tue, 7 Mar 2000 08:36:26 +0800 From: dzorde@xxx.com Subject: Subaru TBI Just down the road from me, good to see some fellow West Aussies on the list. On a different note. I just picked up a Subaru TBI (centre point injection, think its of a 1.8L import motor), the injector is a 1.6 ohm unit. Can someone tell me if this has to be driven as P/H or whether it can be driven as saturated (if so does it need a resistor ?) The plan is to fit this to my supercharged Fiat 850. Dan dzorde@xxx.com (Balcatta, WA) >Adrian Broughton >1990 Celica GT-Four, 1974 VW Kombi, 1967 Holden HR >Fremantle, Western Australia > >Just up the road from me. > >- -- >Real Name: Bernd Felsche > Email: bernie@xxx.au > http://www.perth.dialix.com.au/~bernie - Private HP > - ---------------------------------------------------------------------------- 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: Mon, 6 Mar 2000 16:40:04 -0800 From: "Al Lipper" Subject: RE: attn: help needed This is a multi-part message in MIME format. - ------=_NextPart_000_000A_01BF878A.9FD905E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Ali, I will offer what help I can. I believe Franklin Software has a C cross-compiler for the 8051 (http://www.fsinc.com/) and you may want to look at http://www.fsinc.com/ and http://www.hitex.com/automation/FAQ/8051/ and maybe http://www.PhilipsMCU.com/ftp.html. I hope these will provide useful 8051 unfo. If you have specific questions on the software, I'll try to answer them, but I don't have the time to write the pages of documentation required for ECU6.BAS (though I wish I did :) As far as testing goes, a regular test bed should be fine - All you need is an electric fuel pump and fuel return line. The rest of the sensors, and of course the throttle-body, are part of the EFI system. I don't know what is available there, but you I have purchased used throttle-body units from junkyards for relatively little money. Good luck. Al -----Original Message----- From: Ali Hasan [mailto:u961142@xxx.pk] Sent: Sunday, March 05, 2000 1:02 PM To: efi@xxx.org Subject: attn: help needed Dear Mr. Lipper! I am a student of electronics and, along with two other people, am involved in a final year design project just like your ECU6. We have gone through your files and have found them to be of IMMENSE help in doing our project. But we need some help and explanations regarding some of the features of your project. First of all when we started the project we had in mind to use C/C++ to program the microcontroller, unlike you who have used BASIC. The problem is that as yet we have been unable to find a suitable assembler that would convert the C code into HEX for the 87C51GB. Please guide us in finding one. Secondly we are finding it hard to find a final testing platform for the device once it would be completely implemented. We have an engine test bed in one of our labs here, but the machine runs on a conventional carburetor system. This is the BIGGEST problem that we are facing right now. The readme file that you have appended with the ECU6 folder is helpful enough, but for us who have no teachers here specialized in this kind of automotive systems, it is rather hard to get the intricacies of the software files. We've made some good "guesses" on our part, but we want to be sure of everything. Please send some explanatory material in this regard. We know you might be following a busy schedule, but we only have a month more before our project gets graded. Hence we are in real need for some timely help. We hope that you'll reply and that we could develop some sort of correspondence in the future as well. Thanks in advance! Ali Hasan GIK Instt.of Engg. and Technology Pakistan. - ------=_NextPart_000_000A_01BF878A.9FD905E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Ali,
    I will offer what help I = can. =20 I believe Franklin Software has a C cross-compiler for the 8051 (http://www.fsinc.com/) and you may = want to look=20 at http://www.fsinc.com/=20 and http://www.hitex.com/a= utomation/FAQ/8051/=20 and maybe http://www.PhilipsMCU.com/ftp= .html. =20 I hope these will provide useful 8051 unfo.  If you have specific=20 questions on the software, I'll try to answer them, but I don't have the = time to=20 write the pages of documentation required for ECU6.BAS (though I wish I = did=20 :)  As far as testing goes, a regular test bed should be fine - All = you=20 need is an electric fuel pump and fuel return line.  The rest of = the=20 sensors, and of course the throttle-body, are part of the EFI = system.  I=20 don't know what is available there, but you I have purchased used = throttle-body=20 units from junkyards for relatively little money.  Good=20 luck.
 
 
       &nbs= p;   =20 Al
 
 
 -----Original = Message-----
From:=20 Ali Hasan [mailto:u961142@xxx.pk]
Sent: Sunday, March 05, = 2000=20 1:02 PM
To: efi@xxx.org
Subject: attn: help=20 needed

Dear Mr. Lipper!
I am a student of electronics and, = along with two=20 other people, am involved in a final year design project just like = your ECU6.=20 We have gone through your files and have found them to be of IMMENSE = help in=20 doing our project. But we need some help and explanations regarding = some of=20 the features of your project.
First of all when we started the = project we had=20 in mind to use C/C++ to program the microcontroller, unlike you who = have used=20 BASIC. The problem is that as yet we have been unable to find a = suitable=20 assembler that would convert the C code into HEX for the 87C51GB. = Please guide=20 us in finding one.
Secondly we are finding it hard to = find a final=20 testing platform for the device once it would be completely = implemented. We=20 have an engine test bed in one of our labs here, but the machine runs = on a=20 conventional carburetor system. This is the BIGGEST problem that we = are facing=20 right now.
The readme file that you have = appended with the=20 ECU6 folder is helpful enough, but for us who have no teachers here=20 specialized in this kind of automotive systems, it is rather hard to = get the=20 intricacies of the software files. We've made some good "guesses" on = our part,=20 but we want to be sure of everything. Please send some explanatory = material in=20 this regard.
We know you might be following a busy = schedule,=20 but we only have a month more before our project gets graded. Hence we = are in=20 real need for some timely help.
We hope that you'll reply and that we = could=20 develop some sort of correspondence in the future as = well.
Thanks in advance!
Ali Hasan
GIK Instt.of Engg. and = Technology
Pakistan.
- ------=_NextPart_000_000A_01BF878A.9FD905E0-- - ---------------------------------------------------------------------------- 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: Tue, 7 Mar 100 10:28:27 +0800 (WST) From: Bernd Felsche Subject: Re: Turbo speed sensor ever used ? Espen Hilde writes: >> mmm - Interesting, I'd assumed air flow measurement and MAP would be >> sufficient to determine volume of air entering the chamber. Are you >> suggesting AFM doesn't give an accurate enough figure due to backpressure >> at the turbo and that MAP in no way assists this - in the circumstance >> where we have an AFM and MAP ? >The AFM dont know the backpressure and therefore the ecu cant predict >the right advance....we are wanting to be right on the edge of detonating >here....at a 700hp 2l turbo engine 0,5 degree wrong advance at max torque >is 40 hp lost. The state of the turbo is defined by the operation of the engine. In theory, the ECU should be able to work it out given sufficient knowledge and the appropriate algorithm. If the *backpressure* is so critical, then you should arrange for phasing the exhaust pressure pulses before the turbo so that the exhaust still "scavenges" the combustion chamber as the valve closes during overlap. A reduction in overlap may also be worth considering. You don't really want internal exhaust gas recirculation if your sole quest if for maximum power. >AFM and a MAP sensor on the exhaust could do the trick if the AFM is >fast enough. Those sensors would not be fast enough and sufficiently resistant to the 500+C temperatures in the exhaust. If you're getting 700bhp from 2 litres, you're spinning at close to 10,000 rpm if not more. A pressure sensor needs to pick up the peaks and throughs at the exhaust valve to adapt the airflow. Similarly, to accurately measure the airflow, you need a fast pressure measurement at the inlet as well. There are pulsations in the airflow even with (turbo-)supercharging. Transducers will typically not give you enough information at high speed. Pressure sensors take about a millisecond to respond to a pressure change. So at 10,000 rpm, you get all of 6 samples per revolution - not very accurate in identifying the pulsations. (vis Motorola MPX5700 or MPX4250A) Those sensor need to be mounted remotely from the engine - else they become soup - so you need to have a pressure line to the ECU that introduces minimal delay. An oil-filled tube would improve the response time - you still need to allow for the speed of the wave propagation to determine precise phasing. >How the algorithm or map for backpressure vs .boost should work beets >me....Ignition retard under accleration when backpressure is higher than >steady state... >Its complex...... >Turbo speed VS. engine rpm wot table? >A backpressure table of %influens on volumertric filling at wot? >Use a valve on the exhaust pipe for adjusting backpressure under dyno >runand fill the tables....a hard day work? >Different engines responds different to backpressure at different rpms. Because of the dynamics of the flow as noted above. Having no overlap would go a long way to solving the problem. As you don't have a long exhaust tract, you lose out on taking advantage of an "under-pressure" to help evacuate burnt gases from the combustion chamber as you have a turbocharger sitting in the way, a short distance downstream from the valve. If you had freedom in designing your cylinder head and exhaust valves, I'd suggest that you have one exhaust valve from each cylinder directed to the turbocharger, opening first and a second (or third) valve opening later to a turbo-bypass with the first closing slightly to prevent return flow. That permits a degree of overlap on the second exhaust with the possibility of useful scavenging. With say three camshafts, a variable timing of the second exhaust camshaft and hence the valve timing will also alter the boost pressure - the duration of the second exhaust opening need only be (guessing here!) about 100 degrees. The maximum duration would be determined by the boost requirements and the limit of overlap. Also, the greater the advance on the second exhaust, the greater the scavenging, but the lower the boost. Applying traditional exhaust tuning techniques (resonance, etc) to the bypass exhaust would mean more effective scavenging during overlap as the bypass exhaust is only carrying a portion of the full exhaust flow - between a quarter to a third (again, guessing). >> I've alwayus wondered what the relationshiup is between boost and less >> ignition advance - is it simply chamber filling, propensity to ping, or >> some other presumably non-linear relationship ? >Exhaust backpressure is driving the exhaust temp to the roof..more residual >hotexhaustgasses .more prone to detonation. The higher temperature will also contribute to detonation because the exhaust side stays hot. That may be good for increasing boost, but not so good if you have to lose power by retarding the ignition. If the static backpressure is too high and phasing the exhausts doesn't contribute to better throughflow, then it may be necessary to split the inlet and exhaust systems to equally-phased cylinder groups, necessitating multiple turbo-chargers. - -- Real Name: Bernd Felsche Email: nospam.bernie@xxx.au http://www.perth.dialix.com.au/~bernie - Private HP - ---------------------------------------------------------------------------- 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 #87 **************************** 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".