DIY_EFI Digest Friday, May 14 1999 Volume 04 : Number 283 In this issue: Re: OBD_II You asked for experiences Re: horse power/acceleration Re: Modifying OBD-II systems Re: In cylinder pressure measurement Re: Modifying OBD-II systems Re: alternative engines, WARPED Re: OBD_II You asked for experiences Re: Variable Restrictiveness Exhaust Re: Re:Just out shopping for injectors Re: alternative engines, WARPED Re: Variable Restrictiveness Exhaust Re: Honda Vtec ECU See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Thu, 13 May 1999 22:11:32 EDT From: AL8001@xxx.com Subject: Re: OBD_II You asked for experiences In a message dated 99-05-13 21:01:00 EDT, Wayne.MacDonald@xxx.au writes: With some >research I found it used the OBD_II interface so I built an adapter to >connect a laptop inline before the SAE-J1962 plug, I wrote a program to trace all the >traffic then got the dealer to use the diagnostic tool to reset/read some of the sensors (He didn't know I had a PC connected) I've thought of this as well for my 99 Chrysler 300M engine trans swap. The program you wrote, is is just a serial port recorder? I'm not a programmer and just have started into the word of OBD II stuff. > I then spent the next couple of days at the standards >office going through >the data I had gathered, I found that the first thing the diag tool did was > request that >the ECU unlock, to this the ECU responds with a two byte seed value, the >diag tool then responds >with the correct key for this seed value and the ECU is unlocked. For the American cars, the vehicle serial # is programed in to the ECU. The ECU also has it's own (different) serial # printed on the outside. I wonder if the serial # laters the code. >I hope I have not been a bore. > >Wayne Macdonald. > > Not a bore at all! This is a great story on how to crack the codes! Harold ------------------------------ Date: Thu, 13 May 1999 19:39:04 -0700 From: "Fran and Bud" Subject: Re: horse power/acceleration Try this site for Bowlings Automotive Equations. Even if not exactly what you want, you will like it! http://sura1.jlab.org/~grippo/auto.html - ---------- >From: "Jeff W" >To: >Subject: horse power/acceleration >Date: Thu, May 13, 1999, 2:19 PM > >dear sir >I am writing to you because I am looking for the correct calculation/formula >for finding the approximate horse power conversion from vehicle weight and >acceleration curve. > I am presently in Vancouver community college, in Vancouver B.C and my >instructor (Dave William's) gave me your e-mail address feeling that you may >be of some help to me. > >vehicle weight + acceleration curve + some other things I don't know= >approximate HP@xxx. >thank you! >Jeff Weinberger >sierraj@xxx.com > > ------------------------------ Date: Fri, 14 May 1999 03:00:54 +0000 From: Donald Whisnant Subject: Re: Modifying OBD-II systems > > Date: Thu, 13 May 1999 20:36:14 -0400 > From: Todd Israels > Subject: Re: Modifying OBD-II systems > > Without causing any trouble is it possible to read the current VE table > and replace values in the table through the ADL interface? From what I > have heard from dealer tecs a new VE table or even operational program for > the PCM but they are unaware of being able to read this info, but then they > dont need to? > thanks for any info you can give > Todd Israels > Todd... Anything is possible via the ADL port -- actually called the DLC port on newer vehicles... Reading is actually easier than writing... Since the PCM uses flash memory, you can't write without erasing (unless you are only changing a '1' to a '0')... That means the write code must also know how to erase the flash and the read doesn't and is thus inherently more complex... Also, it means that most "writes" can NOT occur "on the fly" with the vehicle running -- since erasing the flash will kill it, not to mention screwing up checksums... Thats about all I'm allowed to say... Donald ------------------------------ Date: Thu, 13 May 1999 22:34:43 -0500 From: Tom Sharpe Subject: Re: In cylinder pressure measurement All you need is revolutions per mile (each gear) and total weight (mass). Tom Todd....!! wrote: > Charles, it sounds as though you need to get some sorta input as to how > much torque is being produced by the engine.. One way could be to put > two sensors somewhere along the drive shaft or an axle shaft or > something that you could calulate the 'twist' of the shaft using the two > sensors timing differencs due to the varying load on the shaft that they > are located on... ------------------------------ Date: Thu, 13 May 1999 22:46:22 -0500 From: "G. Scott Ponton" Subject: Re: Modifying OBD-II systems Mostly what they have been doing with the OBDII stuff is replacing the PCM with a 95 unit. The 95 unit can be programmed by several sources. The other popular convertion around here (Dallas) is the Accel DFI unit. Accel makes a dedicated harness which plugs into the stock engine sensors and injecters etc. Personally I am slowly Collecting the needed equipment and knowledge to try my hand at programming the OBDII units. I am told there is someone out there who is supposed to be selling software and cables etc. soon. Problem is the rumor mill says it's BIG BUCKS. I guess they figure the normal DIY's aren't capable of using their software or they just want to make sure it's a limited source. As I find out more I will post. Scott P.S. I haven't forgotten the info on my ignition convertion. Just been to busy to sit down an write and dig up 10 year old notes. Will be posting this info soon. ------------------------------ Date: Thu, 13 May 1999 23:02:24 -0500 From: Tom Sharpe Subject: Re: alternative engines, WARPED Just wanted to say that 9" Fords are easier to work on than Dana 60's.. Mopar 8 3/4 are fine unless you need a new Posi. Tom S ------------------------------ Date: Fri, 14 May 1999 00:02:36 -0400 From: "David A. Cooley" Subject: Re: OBD_II You asked for experiences At 10:11 PM 5/13/99 -0400, you wrote: >> I then spent the next couple of days at the standards >>office going through >>the data I had gathered, I found that the first thing the diag tool did was >> request that >>the ECU unlock, to this the ECU responds with a two byte seed value, the >>diag tool then responds >>with the correct key for this seed value and the ECU is unlocked. > > >For the American cars, the vehicle serial # is programed in to the ECU. The >ECU also has it's own (different) serial # printed on the outside. I wonder >if the serial # laters the code. The SAE J-1850 spec states that the manufacturer can use whatever security algorithym they want... IE it's not a standard code formula. The protocol for the communications is a standard, as are the trouble codes... the rest is up to the maker as to how they want it. =========================================================== David Cooley N5XMT Internet: N5XMT@xxx.net Packet: N5XMT@xxx. Member #7068 Sponges grow in the ocean... Wonder how deep it would be if they didn't?! =========================================================== ------------------------------ Date: Thu, 13 May 1999 23:04:15 -0500 From: "G. Scott Ponton" Subject: Re: Variable Restrictiveness Exhaust Ord Miller wrote: >I use high flow cats. For the 1 or 2 HP difference, I really don't think >it's worth the risk of legal problems or injuring my environmental >consience. ;) >On the other hand, I am wondering if I could improve low rpm torque if I >could add a variable restrictor?? I would tend to agree with ORD. I have run vehicles with and with out cats. They seem to have very little if any effect on power output. I think this comes from the early units they used in the start. Back in the 70's the cats were resterictive enough you didn't need a muffler. The cats they have today flow as well as a straight piece of pipe. I have built and installed a 3" crossover and single high flow cat system for a 96 Z28. The engine was a stroked LT1 with ported heads, aftermarket cam, headers etc. and a centrifical blower boosting to 15 PSI. On a chassis dyno it made 605 horses at rear wheels. Passed emissions test here in Dallas with .01 CO and .00 HC at idle and .00 CO and .01 HC at 2500. Biggest gain was installing a cat back system. 3" with Flowmaster. Second biggest was the 3" crossover. The cat had no effect at all so was left in after it was installed. This project is the reason for my interest in learning how to tune OBDII systems. In order to make it drivable ended up with an Accel DFI unit. Although I have no problem with it on the whole, it is a royal pain to tune with all the mods which were done to this car. Also it eliminated the EST system. On this thing it is definetly needed. Scott ------------------------------ Date: Thu, 13 May 1999 22:12:06 -0600 From: "Programmer" Subject: Re: Re:Just out shopping for injectors check out www.lindertech.com tell Jim that Lyndon sent ya--maybe he'll charge you more Check out Bubba's fuel injection tips--you'll love 'em. LWester@xxx.com - -----Original Message----- From: Fisystems@xxx.com> To: diy_efi@xxx.edu> Date: Tuesday, May 11, 1999 6:11 PM Subject: Re:Just out shopping for injectors >Just out shopping for injectors ( GM port, 24-27lb) any ideas for a good >supplier? >Ken Murillo ------------------------------ Date: Fri, 14 May 1999 00:40:40 -0400 From: Shannen Durphey Subject: Re: alternative engines, WARPED Todd....!! wrote: > > I have a 72 Buick 455 in my 72 Jaguar, but the carb that was on it was > jetted for Cheyenne, Wyoming, I already messed up my first 455 that I > put in the Jag due to this carbs' pretetonation causing lean > condition... broke a couple of peices of ring crowns off the top of a > couple a the pistons.... Damage was already done long before I swapped > out the carb for a sea level configured rochester... Well, I don't believe Cheyenne is too much higher than Hardin, MT. Before I left Hardin, I swapped the primary jets for jets that were 2 sizes larger. Once I arrived here (900 ft above sea level) I had to retard the timing slightly. The car is slightly rich now, but I don't use it much so I haven't finished the tuning. This is a 455 buick, 3.08 rear gear, 18mpg on the highway. Shannen ------------------------------ Date: Fri, 14 May 1999 00:51:19 -0400 From: Shannen Durphey Subject: Re: Variable Restrictiveness Exhaust Vacuum operated valve, WOT= bypassed cat. Shannen David A. Cooley wrote: > > How about a test pipe for the cat... > when you need to get it smogged, bolt the cat back in. > > ----- Original Message ----- > From: William T Wilson > To: > Sent: Thursday, May 13, 1999 2:40 PM > Subject: Variable Restrictiveness Exhaust > > > Okay, this seems to be the best place to talk about random, goofy car mods > > that just might work. :} > > > > Suppose I have a car that I want to pass emissions, but I also want it to > > gogood. Why couldn't I make some sort of cat-bypass system which would > > allow the exhaust to flow openly at high revs, but flow through the cat at > > more "normal" RPM? Maybe a solenoid-activated valve attached to the tach, > > or perhaps just a flap on a spring like at the top of a big-diesel > > smokestack. > > > > ------------------------------ Date: Fri, 14 May 1999 00:05:47 -0500 From: Sergio Ivan Ornelas Subject: Re: Honda Vtec ECU It's at http://hybrid.honda-perf.org The guys from the crx performance page are the ones who are trying to program the ecu, their at http://crxhonda-perf.org WILMAN wrote: > ---------- > > From: Wen Yen Chan > > To: diy_efi@xxx.edu > > Subject: Re: Honda Vtec ECU > > Date: Thursday, May 13, 1999 7:29 PM > > > > Hello, > > > > I think they guys on the Honda Hybrid page have reverse engineered the > 1.6 > > vtec's ECU. > > Would you happen to know how I could get on this page? > > > > > Wen > > > > On Wed, 12 May 1999, WILMAN wrote: > > > > > Hello, > > > > > > Is there anybody out there who can help me to reprogram the ECU's > > > found on 1992 onwards Honda Civic EG6 1.6 Vtec. Codes are either > P30-G00 > > > or P30-000. > > > > > > > > > > > > Wilman > > > > > ------------------------------ End of DIY_EFI Digest V4 #283 ***************************** 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".