Ok so ive got a intake and a catback, not too agressive, ive got hks 272's on the horizon. Now my question is i see the stock map with a bunch of 8 and 9's around the 5000 rpm / 160 - 200 % load range. Should they be leaned out? a 9.0 afr is ugly and my narrowband (i know AEM uego coming also) always pegs rich when im wot. Id like to get it back into the middle of the band. any direction on this? should i bring them up to 10's? thanks! -- Jeremy

p.s. damn i such a noob at tuning, this is my first timer.

 

With an intake you could already be lean. Do nothing until you have a wideband on there.

With a wideband on my particular setup I ended up richening by 10% in the early midrange, and leaning by up to 10% at the top. But without a wideband you're BLIND, especially with an intake, engine blow up territory by guessing.

 

yeah, i know i need a wideband. how conservative is mitsu by making it richer than necessary. Im going to do a intake piping leak check today also, that should help. Ive never done one and its got 40k miles and its been taken apart tons by mitsu when i had a bad synchro. Im just saying in general how off is the map, because 8's and 9's at wot near max load is really rich! Just wondering. Thanks.

 

On mine it was 10% rich at the top. I've leaned it to low 11s:1. This is low 10s:1 on the fuel map. However, this is airbox and also has lean spool stuff running.

 

The 8's and 9's that you see in the fuel map are _target_ values only. In reality there are other things behind the scenes that will affect the ultimate AFR target that the ECU will try to shoot for. Also, while the target value may in a lot of instances be close to the actual AFR, it can vary quite a bit ... especially with an aftermarket intake. A narrowband sensor is woefully inadequate to fine tune your AFR, since the voltage it will display for a given AFR can vary with your car's EGT. Just be patient until you get your wideband hooked up.

l8r)