Adapting a 2 bar MAP sensor and wideband O2?
12-18-2001, 09:30 PM
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Adapting a 2 bar MAP sensor and wideband O2? What would have to be done to get these to work with the stock computer.
Why couldn't the stock computer be programmed to take advantage of wideband O2 sensors?
The same thing goes for the 2 bar MAP sensor. What sensor would work and could the computer be programmed to take advantage of it?
I just want to get some people who know what there talking about
in here to discuss this. <img src="graemlins/gr_hail.gif" border="0" alt="[hail]" /> <img src="gr_grin.gif" border="0">
[ December 18, 2001: Message edited by: XLR8NSS ]</p>
Why couldn't the stock computer be programmed to take advantage of wideband O2 sensors?
The same thing goes for the 2 bar MAP sensor. What sensor would work and could the computer be programmed to take advantage of it?
I just want to get some people who know what there talking about
in here to discuss this. <img src="graemlins/gr_hail.gif" border="0" alt="[hail]" /> <img src="gr_grin.gif" border="0">[ December 18, 2001: Message edited by: XLR8NSS ]</p>
12-18-2001, 10:09 PM
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Re: Adapting a 2 bar MAP sensor and wideband O2? Let's see, how should I put this...
Ummmmm, no.
<img src="gr_grin.gif" border="0">
This has been discussed and hashed on the LT1_Edit mailing list multiple times - trying to use something like a Syclone/Typhoon 2-bar MAP sensor on an LT1 car (the LT1 PCM is far more thoroughly hacked than the LS1, BTW). There were thoughts of treating the tables like they were half the resolution (20 to 100 kPa would become 40 to 200 kPa), but stuff would invaribly get thrown off... Such as right before the car is started, the computer takes a measurement of the ambient MAP, and makes calculations based on it (for example, my LT1 PCM logs about 89 kPa at my altitude as "ambient"). That would certainly throw off the calculations. So, there would need to be significant code modifications to the LS1 computer - and hacking through these later PCMs is not an easy task - the file sizes keep getting larger (512 kbytes for a '98 LS1 file). Code bloat is happening within GM PCMs (a la Microsoft and their code bloat - faster, cheaper hardware means sloppier, fatter code to run the same speed <img src="gr_images/icons/wink.gif" border="0"> ).
Now, for the wideband. The wideband O2 sensor is linear across a wide range of air fuel ratios. That is completely incompatible with what the stock PCM is expecting to see. The PCM expects .45 to be stoich, and anything above rich, anything below lean. Our O2s are only linear across a VERY narrow range. Again, code modifications with a hacked PCM, or...
Best bet would be something like a Speedpro, DFI, etc. with the Wideband and multi-bar option. Sure, it's pricey, but it would take a very long time to hack and modify the code to the extent that you could get these to work with the stock computer.
Just calling it like I see it. I'd love to hear opposing thoughts, but these are my observations based on many conversations I've had and seen on the mailing lists. <img src="gr_stretch.gif" border="0">
Andrew
Ummmmm, no.
<img src="gr_grin.gif" border="0">
This has been discussed and hashed on the LT1_Edit mailing list multiple times - trying to use something like a Syclone/Typhoon 2-bar MAP sensor on an LT1 car (the LT1 PCM is far more thoroughly hacked than the LS1, BTW). There were thoughts of treating the tables like they were half the resolution (20 to 100 kPa would become 40 to 200 kPa), but stuff would invaribly get thrown off... Such as right before the car is started, the computer takes a measurement of the ambient MAP, and makes calculations based on it (for example, my LT1 PCM logs about 89 kPa at my altitude as "ambient"). That would certainly throw off the calculations. So, there would need to be significant code modifications to the LS1 computer - and hacking through these later PCMs is not an easy task - the file sizes keep getting larger (512 kbytes for a '98 LS1 file). Code bloat is happening within GM PCMs (a la Microsoft and their code bloat - faster, cheaper hardware means sloppier, fatter code to run the same speed <img src="gr_images/icons/wink.gif" border="0"> ).
Now, for the wideband. The wideband O2 sensor is linear across a wide range of air fuel ratios. That is completely incompatible with what the stock PCM is expecting to see. The PCM expects .45 to be stoich, and anything above rich, anything below lean. Our O2s are only linear across a VERY narrow range. Again, code modifications with a hacked PCM, or...
Best bet would be something like a Speedpro, DFI, etc. with the Wideband and multi-bar option. Sure, it's pricey, but it would take a very long time to hack and modify the code to the extent that you could get these to work with the stock computer.
Just calling it like I see it. I'd love to hear opposing thoughts, but these are my observations based on many conversations I've had and seen on the mailing lists. <img src="gr_stretch.gif" border="0">
Andrew
12-20-2001, 12:42 AM
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Re: Adapting a 2 bar MAP sensor and wideband O2? Oh Well...It was a nice dream.
I wasn't sure if the existing "tables" could be modified or the PCM would have to be reworked. <img src="gr_eek2.gif" border="0">
Camaroholic --> <img src="gr_grin.gif" border="0">
I wasn't sure if the existing "tables" could be modified or the PCM would have to be reworked. <img src="gr_eek2.gif" border="0">
Camaroholic -->
<img src="gr_grin.gif" border="0"> 
