General fuel trims with 550s at idle?

[CR95GST]

I just installed some 550s in my car. I was using the logger to set my low throttle but something struck me- In order to maintain a 0 correction, the SAFC has to be richened up all the way to -8% at idle. Now, 1-(450/550)=0.1818181818 so I would think that a good baseline would be -18% correction at idle. Am I missing something here? I am running a TT RX7 fuel pump re-wired (flows 210lph @ 12v and 43psi). I do not have an AFPR yet, but if anything, I would think that would cause it to run more rich than lean. Any ideas? Also, I pull 20inHG at idle and I checked for vac/boost leaks. Only one I have is a small one at the throttle body shaft seal.

FYI- I am running a 1st gen motor, evoIII16g, full exhaust, full IC piping, SAFC, pocketlogger

 

[kpt4321]

I wouldn't worry about it. That's really fairly normal, it could even just be the deadtime of the larger injectors.

 

[nine5raptor]

My idle correction is 0% on 580s at idle. above that it is -20%. Don't worry about it.

 

[CR95GST]

Wow, this is pretty interesting. I only recently got the logger and 550s and I never looked into this. I assume to adjust the AFC for the other low throttle settings other than idle, I would need to be moving to put load on the engine, am I correct?

 

[nine5raptor]

Just follow Kyle's guide and you should be set up in no time:
http://www.dsmtuners.com/forums/showthread.php?s=&threadid=58403