LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

OBD1 and OBD2 questions

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Old Dec 30, 2005 | 01:39 AM
  #1  
scottslt1z28's Avatar
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OBD1 and OBD2 questions

OK, I will be buying a tune here shortly from PCM4less

what are the advantages from going from OBD2 to OBD1????

is there any REASON too?????

Would there be any performance advantages in doing so????

I dont see how there could be and peformance advantages considering pcm4less will be tuning for MY mods and they can just tell the computer to ignore the !egr, !air, and my rear o2's.


Sooooooo. with all that said, is it really worth the extra money to go from OBD2 to OBD1

PLEASE PLEASE HELP computer guys, if there is ANY reasons please bring them forward. I just want to make the RIGHT decision.

Thanks guys, Later
Old Dec 30, 2005 | 01:50 AM
  #2  
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Re: OBD1 and OBD2 questions

OBD1 is easier to tune.
Old Dec 30, 2005 | 02:49 AM
  #3  
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Re: OBD1 and OBD2 questions

Originally Posted by blackz97
OBD1 is easier to tune.

yeah i have heard that it is easier to tune..........however I wont be tuning it myself
Old Dec 30, 2005 | 08:43 AM
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Re: OBD1 and OBD2 questions

The advantage for me is best described by looking at the following
dyno graph comparison:

OBDII an OBDI Dyno Comparison

OBDII and my car just did not get along. I have no idea why. OBDI
was the ticket for my setup.
Old Dec 30, 2005 | 09:18 AM
  #5  
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Re: OBD1 and OBD2 questions

Some of the tuners are able to find extra power in OBD1, have not seen any real good explaination as to why.

IMO the best reason to go to OBD1 though is if you care to you can buy a cable and then just do all the updates through email, Not a big benifit iof you are looking for a one time tune on a bolton car but if you are constantly modding and needing pcm work it is a huge benifit.
Old Dec 30, 2005 | 11:17 AM
  #6  
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Re: OBD1 and OBD2 questions

OBDI advantages: The tuners can usually get a few extra HP, tuning and datalogging software is cheaper, and you never have to worry about missfire detection.

OBDII advantages: Many guys have run into issues using a high-stall TC and OBDI... OBDII often cures this. Also, OBDI will only support 7000RPM, whereas OBDII is significantly higher. Many people use a properly programmed OBDII PCM to pass the "plug-in" emissions test.

I went OBDI and I'm happy with it. Since I have a 6-speed and a 383 that I only rev to 6500, the high-stall problems and the 7000RPM limit disadvantages don't apply to me. And for emissions testing here, a sniffer test is done.

Last edited by Dave '97 Z28 M6; Dec 30, 2005 at 11:24 AM.
Old Dec 30, 2005 | 11:32 AM
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Re: OBD1 and OBD2 questions

OBD2 might go a couple hundred rpms more than OBD1 but not signifigantly, heard a few reports of about 7200 and that is all she wrote. The high stall OBD1 thing can be addressed by most tuners without a swap to OBD2.
Old Dec 30, 2005 | 01:12 PM
  #8  
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Re: OBD1 and OBD2 questions

I agree that the high-stall issue can often be sorted out with a tuned OBDI PCM. But if someone has OBDII, an A4, and no plans for tuning, but does plan on getting a high-stall TC, they might be better off staying with OBDII. Of course, that may or may not apply to the OP.

As far as the RPM limit goes, I had the impression that the OBDII PCM could support much higher revs, like 9000RPM or so. Again, this likely isn't an issue for the OP.
Old Dec 30, 2005 | 02:12 PM
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Re: OBD1 and OBD2 questions

Originally Posted by truedualws6
The advantage for me is best described by looking at the following
dyno graph comparison:

OBDII an OBDI Dyno Comparison

OBDII and my car just did not get along. I have no idea why. OBDI
was the ticket for my setup.
man that is one flat torque curve
Old Dec 30, 2005 | 02:25 PM
  #10  
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Re: OBD1 and OBD2 questions

ok, from what i've read OBD1 it is................
Old Dec 31, 2005 | 02:29 PM
  #11  
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Re: OBD1 and OBD2 questions

Originally Posted by blkchevyz
man that is one flat torque curve
It's the Crane 104227 baby cam. My goal in cam selection was no lope
and passing CA emmissions. The idle is very close to stock.
Old Jan 6, 2006 | 01:41 AM
  #12  
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Re: OBD1 and OBD2 questions

After thinking about this a bit, I think that 96capricemgr is right and I'm wrong about the RPM limits of OBDII vs. OBDI. I don't know where I heard that OBDII could go to 9000RPM, but I think it's wrong.
Old Jan 6, 2006 | 02:26 AM
  #13  
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Re: OBD1 and OBD2 questions

The OBD II RPM limit is 8000 That is with LS1 Edit & HP Tuners, I know a little about tuning both systems (OBDI & OBDII) and I really think the OBDI is the best option for the one that is always trying to get the most out of his car. Hardware & Software are cheaper and easier to use.......... you don't know how little mods affect your engine till you start tuning your PCM!
Old Jan 6, 2006 | 03:50 AM
  #14  
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Re: OBD1 and OBD2 questions

vettered: What's the limit with the LT1 OBDII? And to get up to 8000RPM, are you adding tables, or does the factory PCM have tables that go that high?
Old Jan 6, 2006 | 04:38 PM
  #15  
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Re: OBD1 and OBD2 questions

Originally Posted by truedualws6
The advantage for me is best described by looking at the following
dyno graph comparison:

OBDII an OBDI Dyno Comparison

OBDII and my car just did not get along. I have no idea why. OBDI
was the ticket for my setup.
So when you get smogged here in CA, do you have to swap back to the obd2? Or do have to have someone "look the other way"? I've considered this but don't know if the machine that it's hooked up to will register that the computer doesn't match the car's vin



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