short exhaust throwing off tune?
07-20-2010, 10:31 PM
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short exhaust throwing off tune? ok guys i was running slp loud mouth 2 mufflers right off my headers and sent my data logs to ion soltan to have him tune it for speed density but he said something wasnt right but didnt know what it was. so today just to quiet the car down i added pipe to the exhaust and it is running about 17 to 1 afr where it was running about 14.7 afr.
does that seem weird?
does that seem weird?
07-21-2010, 12:01 AM
#2
Ion should be able to tell you what was amiss or at least given you something to go on. I highly doubt that adding a short length of pipe to each muffler could affect that.
17:1 is dangerously lean. If that's a true reading on a wide-band, you need to figure out whats going on and quick before you blow something up.
17:1 is dangerously lean. If that's a true reading on a wide-band, you need to figure out whats going on and quick before you blow something up.
07-21-2010, 12:15 AM
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he thinks it might be the computer but wasnt sure. my afr was fine before i added the pipes on. but i also snugged 3 rocker nuts down. im talking maybe a 16th of a turn and those were the only 2 changes made. so i thought ide ask before i adjusted the rockers again
07-21-2010, 01:12 AM
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obviously you are getting the AFR from a wideband correct? If that is the case, where is your bung welded for the wideband and could you have perhaps jarred something loose or had something not seal up for you during the installation of the extra pipe which in turn could be leading to fresh air hitting your sensor? 17:1 makes absolutely no sense even if it is a speed density tune your computer should be able to compensate and be looking for stoich (during non WOT)
07-21-2010, 05:48 PM
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ok guys, ion soltan replied to my email and he said that you must have atleast 4 foot of exhaust in order for the o2 sensors to read right. i had aboout 3 foot wen he was having trouble tuning it then when i added the extra 18"s of pipe it started getting the right readings.