Installed my Utec about 1 month ago and have been running in lean + knock conditions from their Stage 1 map. 20PSI.

after I read most of the post on here about this problem.
I have few questions in my mind.

1) how do I make sure I have the same background map as others that is running the perfect 11.1 A/F ratio per TURBO XS when their fuel colum is set to Zero.

2) I just dont understand how two similar EVO
Basicly stock can be so big of a difference in a/f ration.

{the only thing I have on my car now is a Cat Delete Pipe (where I mount my O2 Sensor) and boost set to 20psi w/utec,}


My car is running basicly 12-12.35 vs Turbo XS 11.1

can someone explain

 

it needs to be tuned, you can't use the off the shelf map and go.

 

yes your right, thanks for your feed back

but my question is not about getting tuned or not.
it more of a comparison.

 

and further more, you can't even see your background map in the UTEC

 

What octane are you running?

 

I'm running on 91 octane

 

If you are running 91 octane you will run at a leaner afr. The base map is for 93 octane. You should probably add a good bit of fuel to get your car to a safer afr.

Thanks,
Jermaine

 

thank you for your post Jermaine,

very interesting 91 to 93 octane will make so big of a difference in AFR.
from 12.35 ~ to 11~ with just 02 octane more
so if I go with 97 octane which one of the 76 gas station sells them
I will be at 8.5 ~ AFR ?

 

It's all dependent on the additives used to make the gas arrive at your octane level.

 

oh I see.
but why does all of the NEW STOCK Mitsubish Evolution VIII accross USA runs rich from the factory setting disregard of the Octane level ?

 

where did you mount your 02 sensor?

 

Mutiple Fuel Maps.