DIY_EFI Digest Saturday, 9 August 1997 Volume 02 : Number 264 In this issue: Re: MAP update on tbi setup RE: DIY_EFI Digest V2 #261 RE: update on tbi setup RE: update on tbi setup Re: MAP Adjusting Boost Re: map Harmonics and Intake Disable VATS Re: TPI Questions RE: Disable VATS Re: MAP Re: TPI Questions Re: Adjusting Boost Re: Adjusting Boost Re: Disable VATS Range Rover Re: Adjusting Boost Re: TPI Questions Re: Range Rover Re: TPI Questions Re: Adjusting Boost Too good to let go by Re: MAP Re: Adjusting Boost Re: Adjusting Boost See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Rich Mauruschat Date: Fri, 8 Aug 1997 09:12:06 +0100 Subject: Re: MAP At 01:58 08/08/97 GMT, you wrote: > >I've asked the question before and have not recieved an answer. > >Anyone out there know what MAP sensor, if any, outputs as a straight voltage >devider, resistor type device? I am looking for something that is basically >a pressure controlled rheostat. >Any ideas? > Isn't this a bourdon gauge with a pot instead of the pointer?! ------------------------------ From: wstrass@xxx.com Date: Fri, 8 Aug 1997 07:11:05 -0400 Subject: update on tbi setup To: DIY --INTERNET DIY From: Wayne Strasser (CED) _______________________________________________________________________ Subject: update on tbi setup This is response to Bruno's question about 15m/s being a goal to keep the flow laminar. I am not sure the reasoning behind this, but I do know two things: 1. 15m/s in that flow regime produces a mean stream Reynolds number of around 35,000 (with a gut-feel estimate for the viscosity of air at that temperature and pressure of 0.016 cps). This is well above the laminar to turbulent transition. 2. The fact that the fluid makes many twists and turns entering the system (this includes the turning around elbows that creats twin helical vortices due to coriolis effect) will enhance the local reynolds number due to all the rotational and recirculating kinetic energy that the air has. In short, you would have to get the flow down to below 1 m/s to get it laminar. _______________________________________________________________________ Wayne Strasser Polymer Development wstrass@xxx.com *** Forwarding note from XXXXXXXX--XXXXXXXX 08/07/97 23:50 *** ========================================================================= Received: from eastman.com by GWVM1F.emn.com (IBM VM SMTP V2R4) with TCP; Thu, 07 Aug 97 23:50:16 TOD Received: by eastman.com id AA48080 (5.67b/IDA-1.5 for wstrass@xxx.com); Thu, 7 Aug 1997 23:50:10 -0400 Received: from gatekeeper.eastman.com by eastman.com with SMTP id AA24269 (5.67b/SMI-4.1 for ); Thu, 7 Aug 1997 23:50:09 -0400 Received: by gatekeeper.eastman.com; id AAA14777; Fri, 8 Aug 1997 00:19:53 - -0400 (EDT) Received: from coulomb.eng.ohio-state.edu(128.146.90.150) by gatekeeper.eastman.com via smap (3.2) id xma014773; Fri, 8 Aug 97 00:19:37 -0400 Received: by coulomb.eng.ohio-state.edu (940816.SGI.8.6.9/940406.SGI) for diy_efi-outgoing id CAA24148; Fri, 8 Aug 1997 02:10:51 GMT Received: from student.canberra.edu.au by coulomb.eng.ohio-state.edu via ESMTP (940816.SGI.8.6.9/940406.SGI) for id WAA24143; Thu, 7 Aug 1997 22:10:46 -0400 Received: from by student.canberra.edu.au (8.7.5/8.7.5) id MAA20465; Fri, 8 Aug 1997 12:10:43 +1000 (EST) Date: Fri, 8 Aug 1997 12:10:42 +1000 (EST) From: Bruno! To: diy_efi@xxx.edu Subject: update on tbi setup Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-diy_efi@xxx.edu Precedence: bulk Reply-To: diy_efi@xxx.edu Hi All, Firstly, thanks to those who replied to my question on throttle bodies and sizing. I used the following specs: engine capacity = 2000 ccs number of cylinders = 4 maximum rpm = 6600 tb id = 40mm = 0.04m throttle shaft area = 8mm x 40mm I also got my hands on an efi plenum for the engine, which came on the later model twin cams, and this has a cross-sectional diameter of 36mm. As the plenum was damaged, and able to split into two parts, i decided i would use the bottom half, which holds the fuel rail and injectors (thereby getting out of having to build one from scratch), and put the throttles on this. So, vol of air for each cyl = (500cc/2) * (6600/60) = 27.5 l/s = 0.0275 m^3/min area of tb = (area of tb id) - (area of shaft) = 9.366 x 10^-4 m^2 air speed = volume / area = 0.0275 / (9.366 x 10^-4) = 29.36 m/s I also found that the runner cross-sectional area is about 8.4% larger (average) than the tb effective area, though the throttle shaft has been machined so that there is less exposed metal at wot. It was mentioned in a previous post by James Boughton that a target air speed of 15 m/s is ideal over the intake air event (or so i read, please correct me if i'm wrong). The figure above is about twice this, and assuming the valve is open for 180 degress (half of intake cycle) , is this about right? What is the reasoning behind the 15m/s figure above? am i trying to keep the air laminar in the intake? I am yet to measure the length of the whole system, though as a side note the twin carb setup un the car right now has a very peaky intake resonance at about 4100 rpm. I had noticed a slightly louder "gargle" at about 2000 rpm when running the engine in (still does - just that i didn't rev past 3000 for a while), the noise at 4000 took me completely by surprise when i first heard it. Good prompt for shifting while street driving :). The intake runner on the efi manifold will ultimately be longer, as it is about the same length without the tbs & trumpets bolted on. Any ideas and comments most welcome. Thanks. Bruno. (b.marzano@xxx.au) On the internet, no-one can hear you scream. ------------------------------ From: John Hess Date: Fri, 8 Aug 1997 08:59:52 -0500 Subject: RE: DIY_EFI Digest V2 #261 Again, reading and writing to the EPROM is no problem. The point of my original post is that these "infomercial" products allow you to read and map the EPROMs. They do what they are advertised to do, yet some would write the "Hot Rod" article off as an infomercial. I do have a few of the memory addresses (thanks to others on this mail group), and am looking for others. As I get them, I am writing small, specialized programs to remove VATS, set the idle table, etc on those specific EPROMS that I can verify the data locations on. When I finish, I will (am) share(ing) the data and programs with contributors - ---------- From: Mark Taschek[SMTP:mtaschek@xxx.com] Sent: Thursday, August 07, 1997 4:32 PM To: diy_efi@xxx.edu Subject: RE: DIY_EFI Digest V2 #261 > > Reading the PROM is actually quite simple. Get a PROM > Reader/Programmer. Get a dual inline header strip. Bend the long > pins outward so that they can be plugged into the Programmer socket. > Plug your Memcal onto the pins sticking up (the pinout for the Prom > is the first (I think 28 pins) of the header. Cut off the rest of > them and you can read (and burn an erased memcal). The trick is not > reading or burning the EPROM; but, in knowing where the various maps > are on the PROM and what they are doing. > > > ---------- > From: Joe Boucher[SMTP:BoucherJC@xxx.com] > Sent: Thursday, August 07, 1997 10:29 AM > To: diy_efi@xxx.edu > Subject: Re: DIY_EFI Digest V2 #261 > > > From: Jennifer Rose > > Date: Wed, 06 Aug 1997 21:39:54 -0700 > > Subject: Re: July "Hot Rod" > > > > [snip] > > > > > > >Hi Joe > > > > Yes - read the article - feel it was mainly infomerchal for > the software > > programs. My .02$ worth. > > > > Vance > > > > ------------------------------ > > Agreed!! Mr. Peterson didn't get rich by being stupid. > > It was informative to me with details I didn't know. I was unaware > how > to read the prom. Reading the prom has been mentioned on the list. > Someone has mentioned having files of various proms. Now I know one > method of doing it. I also know I'll never have the resources to do > it > myself. > > Joe Boucher xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Ok so it has been said through the group that a prom can be read.. (great) now can some one show me what some different tables look like??? example that im looking for is water temp table?? manafold air temp table?? map table??? and timing advace table??? how easy is it to pick out the tables in the hex dump... I have some hex dumps but can't seem to notice any tables?? thanks if anyone can help... eamil mtaschek@xxx.com ------------------------------ From: James Boughton Date: Fri, 8 Aug 1997 10:14:42 -0400 Subject: RE: update on tbi setup >I used the following specs: >engine capacity = 2000 ccs >number of cylinders = 4 >maximum rpm = 6600 >tb id = 40mm = 0.04m >throttle shaft area = 8mm x 40mm >I also got my hands on an efi plenum for the engine, which came on the >later model twin cams, and this has a cross-sectional diameter of 36mm. >As the plenum was damaged, and able to split into two parts, i decided i >would use the bottom half, which holds the fuel rail and injectors >(thereby getting out of having to build one from scratch), and put the >throttles on this. Do you intend to have any ability to adjust length for development? If not, I would suggest a length shorter that what you think is correct. Power can fall off very dramatically once the runner becomes too long, but tends to fall off much more gradually if the runner is too short. >vol of air for each cyl = (500cc/2) * (6600/60) = 27.5 l/s = 0.0275 m^3/min >area of tb = (area of tb id) - (area of shaft) = 9.366 x 10^-4 m^2 In actuality, the average area of the intake system should be used if you are going to use the calculations in the SAE papers by Engleman and Eberhard. >air speed = volume / area = 0.0275 / (9.366 x 10^-4) = 29.36 m/s Very high! >I also found that the runner cross-sectional area is about 8.4% larger >(average) than the tb effective area, though the throttle shaft has been >machined so that there is less exposed metal at wot. The larger runner area should help with the high airflow rates, but unfortunately, now you are creating some of the highest air velocities in region of high turbulence. This cannot be good. I worked with an airflow engineer that would cringe at the process of speeding the air up and slowing it down in the intake system. He believed that the process should be a consistent decrease in area except in the port (which is a different story. >It was mentioned in a previous post by James Boughton that a target air >speed of 15 m/s is ideal over the intake air event (or so i read, please >correct me if i'm wrong). The figure above is about twice this, and >assuming the valve is open for 180 degress (half of intake cycle) , is this >about right? The figure used is 60 m/s over the intake cycle which is 4 times the figure you are using because the intake event is only one of the 4 events of the 4-stroke process. This would put your throttle bodies at about twice what I would suggest. It is really the throttle blade that causes most of the problem, but what can you do? >What is the reasoning behind the 15m/s figure above? am i trying to keep >the air laminar in the intake? 15m/s or 60m/s over the intake event was an empirical number used by a number of intake engineers over the last decade or so. This is changing as engines get better, but since no one understands the mechanisms by which this phenomenon works it is hard to say why. I dealt with an engine that was over 100m/s (I will always quote velocity over the intake event), but that was through development. We started out at around 60m/s. I think part of the historical increase is due to the improvement in ports. Our ports tended to have >0.9 discharge coefficients which I believe helped out a lot. So if you are going to run high velocities, I would invest in some very good port work. >Any ideas and comments most welcome. Thanks. > Bruno. (b.marzano@xxx.au) I might be able to give you my suggestion for length later if I can dig up the spreadsheet, or the SAE paper. It has been a while, but I need to do this for a friend of mine anyway. Regards, Jim Boughton boughton@xxx.net ------------------------------ From: Bruno! Date: Sat, 9 Aug 1997 01:39:13 +1000 (EST) Subject: RE: update on tbi setup On Fri, 8 Aug 1997, James Boughton wrote: [snipped bit about intake] > Do you intend to have any ability to adjust length for development? If not, > I would suggest a length shorter that what you think is correct. Power can > fall off very dramatically once the runner becomes too long, but tends to > fall off much more gradually if the runner is too short. I quickly went to the garage and measured the length of the runner. The manifold part is 155 mm average, and the throttles with the trumpets will be about an extra 100 mm. I am going to try use the trumpets that are on the carbs right now, otherwise, i could whip up some, of different lengths if necessary. > > >vol of air for each cyl = (500cc/2) * (6600/60) = 27.5 l/s = 0.0275 m^3/min > >area of tb = (area of tb id) - (area of shaft) = 9.366 x 10^-4 m^2 > > In actuality, the average area of the intake system should be used if you are > going to use the calculations in the SAE papers by Engleman and Eberhard. If i assumed the area of the tb was the same as the runner due to the reduced area of brass at WOT, then the cross sectional area would be approximately 1000 mm^2, which put into the formula below would give 27.5 m/s. > >air speed = volume / area = 0.0275 / (9.366 x 10^-4) = 29.36 m/s > > Very high! > The figure used is 60 m/s over the intake cycle which is 4 times the figure you > are using because the intake event is only one of the 4 events of the 4-stroke > process. This would put your throttle bodies at about twice what I would suggest. > It is really the throttle blade that causes most of the problem, but what can you do? [stuff on port theory snipped] Before the engine was screwed together my brother and i tidied up the intake and exhaust ports. the intake was port-matched, and left rough, until just near the valve. all casting marks and irregular spots in the ports were removed. Nothing drastic. If you take the amount of air sucked into one cyl (500 cc) and put this into equation, this gives 55 l/s air flow, and over the area, gives about 60 m/s. This is the speed over the intake cycle. The division by 2 in the equation earlier i understood was from the intake event being half a revolution. Comments most appreciated. Thaks very much. Bruno. (b.marzano@xxx.au) On the internet, no-one can hear you scream. ------------------------------ From: clsnyde@xxx.net (Clare Snyder) Date: Fri, 8 Aug 1997 15:42:08 GMT Subject: Re: MAP > >Try a GM one. >3 pins: 5v, gnd, out >the 1 and 2bar units seem to be pretty linear too. > >I think this is what you're after. > >Fred > >At 01:58 AM 8/8/97 GMT, you wrote: >> >>I've asked the question before and have not recieved an answer. >> >>Anyone out there know what MAP sensor, if any, outputs as a straight voltage >>devider, resistor type device? I am looking for something that is basically >>a pressure controlled rheostat. >>Any ideas? >> Pinouts anyone? How about resistance specs? Thanks ------------------------------ From: bibie@xxx.com (Bibiana Lim) Date: Fri, 8 Aug 1997 23:46:14 +0800 Subject: Adjusting Boost Hi Guys, Here goes a silly question which maybe peanuts to all of you out there. Anyway...I've heard that it is possible to make the "kick in the pants" come sooner. What I want is the boost to happen earlier in the lower RPM. I don't know if it means the fuel boost or the turbo. Please help...I'm a lady and the guys just won't show me how to do it. I ain't worry of gettin' my hands dirty... BTW...I'm driving a Nissan 200SX - Turbo version(Japan Import 1990). Thanks Bibie ------------------------------ From: clsnyde@xxx.net (Clare Snyder) Date: Fri, 8 Aug 1997 15:57:02 GMT Subject: Re: map Anyone out there with a speed density EFI GM Vehicle care to chech resistance of the MAP sensor - with plug disconnected and engine not running - - across complete sensor, and from end to centre? Greatly appreciated Thanks ------------------------------ From: wstrass@xxx.com Date: Fri, 8 Aug 1997 12:17:04 -0400 Subject: Harmonics and Intake To: BOWLING --INTERNET Bowling cc: DIY --INTERNET DIY From: Wayne Strasser (CED) _______________________________________________________________________ Subject: Harmonics and Intake Hello Bruce: I have a question/concern about your "optimum intake runner calculation". I have not seen the estimating equation(s) used on this page, but I do assume based on your introductory paragraph that the equations ignore load (charge density) and are only a function of RPM. I would argue that the mean density of the charge in an important factor when estimating the harmonic properties of the flowing gas stream. Here is my reasoning: Since this is a problem of transient momentum and energy transfer, we can revert to fundamental Eulerian continuum mechanics to provide necessary conservation laws (mass, momentum, energy, and angular momentum).. Assuming the following: 1. Isentropic, irreversible system a. The momentum flux (double dot product between the shear stress tensor and the diadic product grad v) and the heat flow (grad dotted into heat flux) are allowed to vanish from the equations b. The time scale needed to change the temperature of the gas stream is much greater than the time scale of velocity profile development 2. Equilibrium local velocities, temperatures, and pressures a. No shock wave present b. No mechanical energy dissipated it can be shown that the speed and amplitude of the pulses "bouncing" around in the intake medium are a direct function of both the mean and instantaneous charge density. I would like to know more about your calculations and how they were empirically determined. Thanks for your time. _______________________________________________________________________ Wayne Strasser Polymer Development wstrass@xxx.com ------------------------------ From: Terry Martin Date: Fri, 08 Aug 1997 10:00:11 -0700 Subject: Disable VATS >Date: Thu, 7 Aug 1997 13:48:43 -0400 >From: David Goodhue >Subject: How can I disable Vats? > >My friend just bought a totalled 92 Z28 60K miles 350, (for $300). >The drivetrain was not hurt in the accident. The kid who he bought >it off of, lost the keys to it (probally had to do with drinking and >driving). My friend would like to part the car out. Before he pulls >the engine he would like to video tape the motor running, but he doesn't >know if their is an easy way to bypass the VATS. Any susgestions? > >Dave >86 Conv. The cheapest way is get a 555 timer and clock it at a 50% duty cycle for the PCM VATS terminal to ground. Have a look at the Mitchell PCM wiring diagram and trouble shooting the VATS section. It doesn't straight out say it, but they even draw a little square wave pattern on the diag., and tell you the 5v pull-up on the PCM should drop to 2.5v if the VATS is working. Or if you want to get real cheap get a little electric motor out of a kids toy, and put a piece of tape to insulate 1/2 of the shaft. Use that as an armature and drag a piece of wire on it. You can vary the motor speed, and when you hit the right pulse rate, away goes the PCM. I bet nobody ever fiqured a McCullough loop for this :-) Go fiqure. Terry ------------------------------ From: Joe Boucher Date: Fri, 08 Aug 1997 12:40:46 -0500 Subject: Re: TPI Questions [snip] > >3. Any concerns with eliminating the EGR valve. > Noy sure but, without egr there could be more pinging (detination) If you are chunking the EGR valve just because it's the EGR valve, allow me to offer you a differing opinion. The EGR valve does not dilute the mixture during full throttle acceleration. When you are cruising or at part throttle, the EGR allows the engine to run at leaner mixtures. If you are running a stock ECM and prom and you don't have an EGR then you run the risk of detonation at part throttle settings. Bottom line, the EGR won't hurt your performance and the driveability will be better. Unless your striving for a cosmetic goal or just want less complexity, I think you should connect it. Joe (That's my story and I'm sticking to it) Boucher '81 TBI Suburban '70 RS/SS Camaro ------------------------------ From: John Hess Date: Fri, 8 Aug 1997 13:02:42 -0500 Subject: RE: Disable VATS If you can reprogram the EPROM, try this. Change EPROM Memory address &H0016 from &H10 to &H00 Subtract &H10 from what you find at EPROM Memory address &H0007 write the resulting file back to the EPROM. Address &H0016 is the VATS Address &H007 is the low byte of the Checksum. >---------- >From: Terry Martin[SMTP:terry_martin@xxx.ca] >Sent: Friday, August 08, 1997 12:00 PM >To: diy_efi@xxx.edu >Subject: Disable VATS > >>Date: Thu, 7 Aug 1997 13:48:43 -0400 >>From: David Goodhue >>Subject: How can I disable Vats? >> >>My friend just bought a totalled 92 Z28 60K miles 350, (for $300). >>The drivetrain was not hurt in the accident. The kid who he bought >>it off of, lost the keys to it (probally had to do with drinking and >>driving). My friend would like to part the car out. Before he pulls >>the engine he would like to video tape the motor running, but he doesn't >>know if their is an easy way to bypass the VATS. Any susgestions? >> >>Dave >>86 Conv. > >The cheapest way is get a 555 timer and clock it at a 50% duty cycle for >the PCM VATS terminal to ground. Have a look at the Mitchell PCM wiring >diagram and trouble shooting the VATS section. It doesn't straight out >say it, but they even draw a little square wave pattern on the diag., >and tell you the 5v pull-up on the PCM should drop to 2.5v if the VATS >is working. > >Or if you want to get real cheap get a little electric motor out of a >kids toy, and put a piece of tape to insulate 1/2 of the shaft. Use that >as an armature and drag a piece of wire on it. You can vary the motor >speed, and when you hit the right pulse rate, away goes the PCM. > >I bet nobody ever fiqured a McCullough loop for this :-) > >Go fiqure. > >Terry > > ------------------------------ From: Fred Miranda Date: Fri, 8 Aug 1997 13:29:27 -0500 (CDT) Subject: Re: MAP Maybe I did misunderstand what you're after. The GM sensors are active, not passive as a pot. Maybe if you describe what you're trying to do someone can answer better then I have. Fred At 03:42 PM 8/8/97 GMT, you wrote: >> >>Try a GM one. >>3 pins: 5v, gnd, out >>the 1 and 2bar units seem to be pretty linear too. >> >>I think this is what you're after. >> >>Fred >> >>At 01:58 AM 8/8/97 GMT, you wrote: >>> >>>I've asked the question before and have not recieved an answer. >>> >>>Anyone out there know what MAP sensor, if any, outputs as a straight voltage >>>devider, resistor type device? I am looking for something that is basically >>>a pressure controlled rheostat. >>>Any ideas? >>> >Pinouts anyone? How about resistance specs? > >Thanks > > > ------------------------------ From: Jeffrey R Muehl Date: Fri, 08 Aug 1997 13:37:47 -0500 Subject: Re: TPI Questions Thank you for your response - this is exactly what I was looking for. I do understand that at idle and under full throttle EGR is inactive. I am running headers on this motor so I do not have a source for exhaust for EGR. Next question: Is there something I can do with the fuel regulator vacuum line to increase fuel pressure at part throttle, (and increase fuel delivery hopefully avoiding detonation). >From what I've read, illuminating EGR and increasing fuel delivery at part throttle helped throttle response. Any guesses on how much I need to richen the mixture when EGR would have been active? [snip] >> >3. Any concerns with eliminating the EGR valve. >> Noy sure but, without egr there could be more pinging (detination) > >If you are chunking the EGR valve just because it's the EGR valve, allow >me to offer you a differing opinion. > >The EGR valve does not dilute the mixture during full throttle acceleration. When you are cruising or at part >throttle, the EGR allows >the engine to run at leaner mixtures. If you are running a stock ECM >and prom and you don't have an EGR then you run the risk of detonation >at part throttle settings. > >Bottom line, the EGR won't hurt your performance and the driveability >will be better. Unless your striving for a cosmetic goal or just want >less complexity, I think you should connect it. > >Joe (That's my story and I'm sticking to it) Boucher >'81 TBI Suburban '70 RS/SS Camaro ------------------------------ From: bwmsbldr@xxx.com (William A Williams) Date: Fri, 8 Aug 1997 12:44:18 -0600 Subject: Re: Adjusting Boost Ok here is the story. In general the lower the A/R number of the turbine side of the turbocharger the sooner the boost comes in. This number describes (in effect) how much the exhaust is throttled down on it's way to the turbine wheel. The problem is that the sooner the boost comes in the quicker it climbs out of sight and most of your exhaust is going out the waste gate. This holds more back pressure in the exhaust manifold which isn't good. Like a restrictive exhaust. Rather than an expensive change in turbos you should look into a slightly improved cam. This might give you what you need at a lower cost and without the side effects at higher RPM. Don't let the "guys" get you down. An engineering friend at DEC in Colorado Springs once told me that her manicurist asked what she did to her fingernails. There was a stunned silence when she said " Changed the spark plugs in my Audi!" Bill in Boulder ---- "Engineering as an Art Form" ---- ------------------------------ From: Ed or Jose Date: Fri, 08 Aug 1997 02:46:26 -0700 Subject: Re: Adjusting Boost Bibiana Lim wrote: > > Here goes a silly question which maybe peanuts to all of you out there. > Anyway...I've heard that it is possible to make the "kick in the pants" come > sooner. What I want is the boost to happen earlier in the lower RPM. I don't > know if it means the fuel boost or the turbo. Please help...I'm a lady and > the guys just won't show me how to do it. I ain't worry of gettin' my hands > dirty... > I'd recommend an electronic boost controller from the likes of GReddy, HKS, or A'pex. You can also run a mechanical boost controller using easy to access parts...there's a DIY setup in www.supras.com and I believe also in www.dsm.org. What these do is basically "fool" the wastegate into boosting sooner. - -Ed ------------------------------ From: "Greg Abarr" Date: Fri, 8 Aug 1997 14:30:57 -0500 Subject: Re: Disable VATS - ---------- From: John Hess To: 'diy_efi@xxx.edu' Subject: RE: Disable VATS Date: Friday, August 08, 1997 1:02 PM If you can reprogram the EPROM, try this. Change EPROM Memory address &H0016 from &H10 to &H00 Subtract &H10 from what you find at EPROM Memory address &H0007 write the resulting file back to the EPROM. Address &H0016 is the VATS Address &H007 is the low byte of the Checksum. >---------- >From: Terry Martin[SMTP:terry_martin@xxx.ca] >Sent: Friday, August 08, 1997 12:00 PM >To: diy_efi@xxx.edu >Subject: Disable VATS > >>Date: Thu, 7 Aug 1997 13:48:43 -0400 >>From: David Goodhue >>Subject: How can I disable Vats? >> >>My friend just bought a totalled 92 Z28 60K miles 350, (for $300). >>The drivetrain was not hurt in the accident. The kid who he bought >>it off of, lost the keys to it (probally had to do with drinking and >>driving). My friend would like to part the car out. Before he pulls >>the engine he would like to video tape the motor running, but he doesn't >>know if their is an easy way to bypass the VATS. Any susgestions? >> >>Dave >>86 Conv. > >The cheapest way is get a 555 timer and clock it at a 50% duty cycle for >the PCM VATS terminal to ground. Have a look at the Mitchell PCM wiring >diagram and trouble shooting the VATS section. It doesn't straight out >say it, but they even draw a little square wave pattern on the diag., >and tell you the 5v pull-up on the PCM should drop to 2.5v if the VATS >is working. > >Or if you want to get real cheap get a little electric motor out of a >kids toy, and put a piece of tape to insulate 1/2 of the shaft. Use that >as an armature and drag a piece of wire on it. You can vary the motor >speed, and when you hit the right pulse rate, away goes the PCM. > >I bet nobody ever fiqured a McCullough loop for this :-) > >Go fiqure. > >Terry > > unsubscribe diy_efi greg@xxx.com ------------------------------ From: collet Date: Fri, 08 Aug 1997 22:28:12 +0200 Subject: Range Rover For the two persons who ask for the wiring of Range Rover 3,5 with Luca EFI try HAYNES Manuels. It's technical book about many cars, they come from England, you will see all wiring. (But unfortunatly not the schematic of the ECU) Their site:http://www.haynes.com. ------------------------------ From: Dan Date: Fri, 08 Aug 1997 16:30:31 -0400 Subject: Re: Adjusting Boost I have been wondering about electronic boost controllers (EBC) because I have heard at lot of stuff that just didn't make sense. Seems to me that the main benefit is that it keeps the wastegate closed longer before opening up. A regular wastegate using a spring starts to open before the boost is near the desired level so that the wastegate is fully opened by the time (or rather pressure) that the maximum boost is reached. I don't see that it will add any more top horsepower, but maybe some middle HP after reaching about 1/2 full boost. The people selling the EBC (or EVC) talk about an extra 50HP on my 435HP, .85Bar engine but I am skeptical. Anybody do a controlled test with these? I have talked to a guy who does some racing (pretty successful too) and he doesn't think much of EBC. What about the difference between high quality vs low quality wastegates? Do the better ones stay closed longer using a regular pressure regulator? I am using an HKS racing wastegate now which maintained a very consistent boost on the engine dyno unlike another wastegate I once had. ------------------------------ From: "Mike Palmer" Date: Fri, 8 Aug 1997 17:16:39 EST5DST Subject: Re: TPI Questions > Date: Fri, 08 Aug 1997 13:37:47 -0500 > From: Jeffrey R Muehl > Subject: Re: TPI Questions > To: diy_efi@xxx.edu > Reply-to: diy_efi@xxx.edu > > Thank you for your response - this is exactly what I was looking for. > > I do understand that at idle and under full throttle EGR is inactive. > I am running headers on this motor so I do not have a source for exhaust > for EGR. > Next question: Is there something I can do with the fuel regulator vacuum > line to increase fuel pressure at part throttle, > (and increase fuel delivery hopefully avoiding detonation). > My 1994 Probe GT has a solenoid (called the FPRC or Fuel Pressure Regulator Control) solenoid that uses a PWM (I think :) waveform from the PCM and bleeds vacuum at selected times from the vacuum line to the regulator. I wonder if you could find this piece at a wreckers and build a small electronic box with a "knob" sticking out of it that just fed varying voltage or a PWM signal to the solenoid to make the FP regulator adjustable from the driver's seat. It's one idea (however cheesy...) - - Mike - ------------------------------------------ 1994 Probe GT Leather/PMoonroof/5-speed "You'll laugh, you'll cry, you'll hurl..." - ------------------------------------------ ------------------------------ From: Terry Martin Date: Fri, 08 Aug 1997 15:51:59 -0700 Subject: Re: Range Rover collet wrote: > > For the two persons who ask for the wiring of Range Rover 3,5 with Luca > EFI try HAYNES Manuels. It's technical book about many cars, they come > from England, you will see all wiring. (But unfortunatly not the > schematic of the ECU) Their site:http://www.haynes.com. And I thought they sold underwear :-) ------------------------------ From: "George M. Dailey" Date: Fri, 8 Aug 1997 18:18:03 -0500 (CDT) Subject: Re: TPI Questions Ah ha! That's probably why my milage was so bad with my TPI set up. On advice of Peter F., I attempted to bump it up to 12 btdc. Ratteled like a coffee can full of 3/4" marbles. I discovered that I had it set at 4 degrees and was able to bump it up to 6 degrees without detonation. Picked up some extra milage too, I'd say I'm at 13-14 mpg city now. My EGR is disconnected due to a leaking actuator. Maybe I can bump it to 14 once it's repaired. Thanks again Peter. GMD At 12:40 PM 8/8/97 -0500, you wrote: >[snip] > >> >3. Any concerns with eliminating the EGR valve. >> Noy sure but, without egr there could be more pinging (detination) > >If you are chunking the EGR valve just because it's the EGR valve, allow >me to offer you a differing opinion. > >The EGR valve does not dilute the mixture during full throttle >acceleration. When you are cruising or at part throttle, the EGR allows >the engine to run at leaner mixtures. If you are running a stock ECM >and prom and you don't have an EGR then you run the risk of detonation >at part throttle settings. > >Bottom line, the EGR won't hurt your performance and the driveability >will be better. Unless your striving for a cosmetic goal or just want >less complexity, I think you should connect it. > >Joe (That's my story and I'm sticking to it) Boucher >'81 TBI Suburban '70 RS/SS Camaro > > George M. Dailey gmd@xxx.com ------------------------------ From: DemonTSi@xxx.com Date: Fri, 8 Aug 1997 19:48:20 -0400 (EDT) Subject: Re: Adjusting Boost In a message dated 97-08-08 18:39:49 EDT, you write: << The people selling the EBC (or EVC) talk about an extra 50HP on my 435HP, .85Bar engine but I am skeptical. Anybody do a controlled test with these? I have talked to a guy who does some racing (pretty successful too) and he doesn't think much of EBC. >> The reason for the increased power usually does not come with the wastegate opening later (which in most cases it doesn't really do...) but with most reliable electronic boost controllers, you are able to raise and maintain the boost pressure...hence the increase in power. One thing is for sure though, EBCs are way more reliable than most standard manual boost controllers...which have a tendency of overboosting. Van ------------------------------ From: Terry Martin Date: Fri, 08 Aug 1997 16:50:09 -0700 Subject: Too good to let go by The following was posted to this list, and commented on by almost nobody. I think it deserves more attention than that. >I'm not subscribed to the list, but have this suggested url that would >highly educational >to anyone interested in automotive fuel systems. >http://www.inett.com/himac/ OOOH, now I know why my 2 ton vehicle only gets 8mpg. And all this time I thought it might have something to do with thermo-dynamics, volumetric efficiency, or common sense. Wasn't there a cartoon character named Poque? But I've been highly educationalized now, and thank (or was that by?) christ my vehicle gets, what was it again? Oh yeah, 100mpg. Even better on down-grades, so I try to stay with them. I bet with a MAGNET attached to my fuel line I could energize the atoms, or was that molecules?, whatever, and get even more free energy from its intrinsic poential. If I tie in RADIO waves, and ELECTRONIC beams that the government uses to spy on me, I could make it fly, maybe even go into SPACE, where the MAGNETIC FLUX would propel me ever onward. Hmmmm. Then again maybe not. Oh well, sigh.... ------------------------------ From: clsnyde@xxx.net (Clare Snyder) Date: Sat, 9 Aug 1997 00:44:31 GMT Subject: Re: MAP >Maybe I did misunderstand what you're after. > >The GM sensors are active, not passive as a pot. > >Maybe if you describe what you're trying to do someone can >answer better then I have. > >Fred > >At 03:42 PM 8/8/97 GMT, you wrote: >>> >>>Try a GM one. >>>3 pins: 5v, gnd, out >>>the 1 and 2bar units seem to be pretty linear too. >>> >>>I think this is what you're after. >>> >>>Fred >>> >>>At 01:58 AM 8/8/97 GMT, you wrote: >>>> >>>>I've asked the question before and have not recieved an answer. >>>> >>>>Anyone out there know what MAP sensor, if any, outputs as a straight voltage >>>>devider, resistor type device? I am looking for something that is basically >>>>a pressure controlled rheostat. >>>>Any ideas? >>>> >>Pinouts anyone? How about resistance specs? >> >>Thanks >> >> >> > > I've got one, off of the vehicle, that I want to test and see exactly what it does and iff I can use it on a project (---++----) ( O O O ) (---------) 1 2 3 Which pin is +5V, Which is Ground, and which (obviously the only one left is the signal? Facing the connector on the MAP, connector up and vac line to left. ------------------------------ From: Seth Date: Fri, 8 Aug 1997 17:42:33 -0700 (PDT) Subject: Re: Adjusting Boost On Fri, 8 Aug 1997, Bibiana Lim wrote: > Hi Guys, > > Here goes a silly question which maybe peanuts to all of you out there. > Anyway...I've heard that it is possible to make the "kick in the pants" come > sooner. What I want is the boost to happen earlier in the lower RPM. I don't > know if it means the fuel boost or the turbo. Please help...I'm a lady and > the guys just won't show me how to do it. I ain't worry of gettin' my hands > dirty... > > BTW...I'm driving a Nissan 200SX - Turbo version(Japan Import 1990). > > Thanks > > Bibie > Bibie- you could change the turbo, go to a cam with less overlap. But for about $800, you could get rid of the lag with a nitrous system. A very quick shot of 1-2 seconds at full throttle brfore the turbo spins up will give and instant 50 hp or so, and make it shut off as soon as the manifold pressure goes above atmospheric. Instant power and much faster turbo spool up. And in most cases, the nitrous in emissions legal, with a CARB exemption sticker. Seth Allen ------------------------------ From: Ed or Jose Date: Fri, 08 Aug 1997 08:50:26 -0700 Subject: Re: Adjusting Boost Dan wrote: > > I have been wondering about electronic boost controllers (EBC) because > I have heard at lot of stuff that just didn't make sense. > > Seems to me that the main benefit is that it keeps the wastegate > closed longer before opening up. A regular wastegate using a spring > starts to open before the boost is near the desired level so that > the wastegate is fully opened by the time (or rather pressure) that the > maximum boost is reached. I don't see that it will add any more > top horsepower, but maybe some middle HP after reaching about 1/2 full > boost. You're correct. Running an EBC will usually give you more midrange power. Also, an advantage with the EBC is the ability to hold a set amount of boost without worrying about spiking or overboosting. > The people selling the EBC (or EVC) talk about an extra 50HP on > my 435HP, .85Bar engine but I am skeptical. Anybody do a controlled > test with these? I have talked to a guy who does some racing (pretty > successful too) and he doesn't think much of EBC. > > What about the difference between high quality vs low quality > wastegates? Do the better ones stay closed longer using a regular > pressure regulator? I am using an HKS racing wastegate now which > maintained a very consistent boost on the engine dyno unlike another > wastegate I once had. It's usually not the wastegate design that's the problem...it's usually the wastegate spring. I had such a problem when dyno testing/tuning a project car for Muscle Mustangs and Fast Fords magazine. Boost was rather incosistent, and would not go any higher after numerous adjustments. After pulling out the spring and replacing it with a new one (luckily had a identical wastegate lying around), we were able to continue testing/tuning. - -Ed ------------------------------ End of DIY_EFI Digest V2 #264 ***************************** 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".