How much should I back off the ignition timing while tunning (with crome) a 12.5:1 itr motor? It's running 93 octane and ctr cams. First couple tunning pulls in vtec we got the air fuel ratio down to low 13s high 12s but then when you let off the gas it back fires and throws a check engine light (didn't pull the code because we just reset it, will check next time). I got a feeling that knock sensor is acting up a little, plus the o2 does not seem to respond at all. We know that o2 fucked and need to be replaced. Any tips? Please no flaming...

 

Listen carefully
Get your car on a dyno

 

okay I know that. We need to base map it first make sure that it doesn't have any missfires and hold compression and all that. Still need to break the motor in all the way before it goes on the dyno. I was just wondering what's safe on a 12.5:1 comperession motor with 93 octane

 

or better yet can somebody give me their crome map bin.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ABK &raquo;</TD></TR><TR><TD CLASS="quote">or better yet can somebody give me their crome map bin.</TD></TR></TABLE>
From my experience they wont,,..