Hi all,

New to logging had a few questions regarding logging AFR and Boost.

Just has car tuned and AFR's were spot on Dyno.

1. Boost: ECU based boost control with Grimspeed. # on MAP senor is MN 153281.

AEM boost gauge shows 26 psi in 3rd gear WOT.
I selected JDM Map in Evoscan, 0.19347*x-14.7. I'm @ sea level

2. AFR: AEM wideband. I'm using rear 02 mod to log through ECU. No serial cable.
Formula I'm using is:
0.03913*x+9
Forgot where I found it but, it looks off based on log values.

thanks for you help

 

For logging boost...you're going to need to get a Omni 4 Bar Map Sensor. The stock map sensor which is what you have only reads vacuum...and a very small window of boost...I believe only up to like 1 psi...

 

MN 153281 is a EVO 9 3 bar map sensor.

 

Your AFR looks off in the logs?

 

yeah, if you look @ AEM UEGO, the #'s are too low. On Dyno AFR's much more in line with AFR settings.

I'm gonna try playing with the formula in EVO Scan

Someone else used 0.03913*x+10 instead of 0.03913*x+9

 

Yea, you have to play with that number to get the logs numbers to match the gauges. It has to do with where you grounded your gauge.

It works best to log both your rear O2 AFR and then your AEM from serial so you can see both side by side on a chart and then know how much to change it by.

 

thanks, I'll give that a try later.