obd1 - obd2 swap??
02-17-2006, 07:53 PM
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obd1 - obd2 swap?? ok this is what im doing, i have a 69 chevelle and i have put in a 97 camaro motor and the t56. I have been told from a friend that i can use a computer from the 94-95 camaro and plug it in to the 97 wiring harness. I was wondering is this possible.
I am using the full harness from the 97 including the column gauges.
I am using the full harness from the 97 including the column gauges.
02-17-2006, 08:22 PM
#2
Yes, many of us with 96-7 cars swap to OBD1 pcm because tuning and datalogging is much much cheaper. Some tuners claim to get a few more HP out of the OBD1, I don't understand why, the OBD2 pcm is supposed to process faster which you would think would help, but I am in no position to argue with professional tuners who make this claim and I am not paying to have my old OBD2 pcm programmed to find out if it makes less power.
02-17-2006, 08:32 PM
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ok so I can got to my local parts place grab a new computer and just plug it in, what happens with the coded key? or is that a diferent item all together? b/c this is going in to my chevelle i have removed all the smog stuff except the o2's when i run the obd1 computer i can drop the rear o2's right i just want to make sure its going to be mostly plug and play.
02-17-2006, 11:43 PM
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hey thanks man u have been a big help anything elts you think i should do to help the motor out. the set up will be a cold air intake from the bumper and 1 3/4 headman headers with true duel 2 1/2" magna flow that will dump infront of the rear tire. the car only ways about 3600lb.
02-18-2006, 08:41 AM
#6
How much cam and any head work?
I know this will be an unpopular answer here but for a stockish motor 1 5/8" is better for average power unless you spin say north of 6500rpms. Here is some testing one of the Impala SS guys did. http://home.comcast.net/~mmsmith17/ look in the "tech" section. He thought that on his heads/cam/juice/ car the 1 3/4" 4into1s would be best, turned out the 1 5/8 Tri-Ys made the most average power and he would have to spin past 6800 to take advantage of the extra HP the quads offered at higher rpms.
I know this will be an unpopular answer here but for a stockish motor 1 5/8" is better for average power unless you spin say north of 6500rpms. Here is some testing one of the Impala SS guys did. http://home.comcast.net/~mmsmith17/ look in the "tech" section. He thought that on his heads/cam/juice/ car the 1 3/4" 4into1s would be best, turned out the 1 5/8 Tri-Ys made the most average power and he would have to spin past 6800 to take advantage of the extra HP the quads offered at higher rpms.
02-18-2006, 09:40 AM
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i was thinking about a mild cam but i dont want to hert the drive ablity of the car i want to still be able to do long hauls in it do u have any recomidations for the cam.
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02-18-2006, 10:02 AM
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The ONLY thing you need to take care of when going from OBDII to OBDI is the knock sensor.
The "ideal" thing in your situation would be to get a new knock sensor, for a '94-95 F-body. That way the PCM stays stock. You also only need to run the front O2 sensors (don't need the rears any more).
If you don't want to buy a knock sensor, you can buy a 3.9k resistor from Radio Shack, open up the PCM, and carefully solder it on the back side of the circuit board between Blue 22 and Blue 1 (it will lay down between the row of pins - but use some insulating piece of electrical tape wrapped around the resistor to prevent shorts).
I converted my OBD1 car to OBDII at one time. The OBDII PCM has better automatic transmission control - the OBD1 PCM simply could not handle my 3500 stall converter. It'd freak out and send me in to "soft shift to third" limp home mode. The OBDII computer never did that.
But stuff for OBDI PCMs is less expensive (scan tool, programming tools). That's the biggest reason for it. Consider if you want to program an OBDII PCM, you're looking at AutoTap to scan it ($300-ish), LT1Edit for OBDII or Tunercat (haven't checked lately, but let's say $400-ish). Versus $90 for a cable, plus free scan software, plus $90 tunercat. Darn near the same thing, but for 1/3 the price.
Now, if you buy an OBD1 PCM from a parts store, odds are very good that it will NOT have the right program in it. You'll need to find the right program on the 'net (or send me an email / PM and I'll email you one, I have all of them). You'll need to match it up to your combo - M6 transmission. And keep in mind that not all 16188051 PCMs ran a 350ci motor... there was a 262ci L99 that used it as well (Caprices). So the program that's in the PCM could be for that motor... in which case, your motor won't run very well at all (heh, been there, done that). But that PCM can be reprogrammed to run your motor just fine. Did that too.
The "ideal" thing in your situation would be to get a new knock sensor, for a '94-95 F-body. That way the PCM stays stock. You also only need to run the front O2 sensors (don't need the rears any more).
If you don't want to buy a knock sensor, you can buy a 3.9k resistor from Radio Shack, open up the PCM, and carefully solder it on the back side of the circuit board between Blue 22 and Blue 1 (it will lay down between the row of pins - but use some insulating piece of electrical tape wrapped around the resistor to prevent shorts).
I converted my OBD1 car to OBDII at one time. The OBDII PCM has better automatic transmission control - the OBD1 PCM simply could not handle my 3500 stall converter. It'd freak out and send me in to "soft shift to third" limp home mode. The OBDII computer never did that.
But stuff for OBDI PCMs is less expensive (scan tool, programming tools). That's the biggest reason for it. Consider if you want to program an OBDII PCM, you're looking at AutoTap to scan it ($300-ish), LT1Edit for OBDII or Tunercat (haven't checked lately, but let's say $400-ish). Versus $90 for a cable, plus free scan software, plus $90 tunercat. Darn near the same thing, but for 1/3 the price.
Now, if you buy an OBD1 PCM from a parts store, odds are very good that it will NOT have the right program in it. You'll need to find the right program on the 'net (or send me an email / PM and I'll email you one, I have all of them). You'll need to match it up to your combo - M6 transmission. And keep in mind that not all 16188051 PCMs ran a 350ci motor... there was a 262ci L99 that used it as well (Caprices). So the program that's in the PCM could be for that motor... in which case, your motor won't run very well at all (heh, been there, done that). But that PCM can be reprogrammed to run your motor just fine. Did that too.
02-18-2006, 01:54 PM
#9
You can take a fairly big step up in cam size before drivability is compromised. The Caprice LT1 came with a 191/195 cam and I replaced it with a 208/221 cam(ZZ3/zz4 crate motor cam) and even with 2.03s and 1650 stall it drove fine and it has a race weight without me of like 4100lbs.
For a sleeper I would say the Crane 227 cam 210/224 nice mid and upper rpm gains but docile as stock, you want a little lope go up into mid to upper 21X range on the usual 112. Any cam swap will require pcm reprogramming and new valvesprings with roller rockers being a good idea as well.
For a sleeper I would say the Crane 227 cam 210/224 nice mid and upper rpm gains but docile as stock, you want a little lope go up into mid to upper 21X range on the usual 112. Any cam swap will require pcm reprogramming and new valvesprings with roller rockers being a good idea as well.
