Ideal timing and 02 voltage

[tim_korn_99]

Ok, my pocketlogger should be in tomorrow, but before i start logging, i would like to know what the ideal timing advance and 02 voltage are.
I always run 93 octane, and i will be tuning for about 20psi on an EVOIII 16g, 255 pump, 550cc injectors, s-afcII, and all the usual supporting mods.
Im thinking i should shoot for a steady 14-15 degrees advance? does that sound about right?
I just want to get all the info i can before i start tuning too much.
Thanks
-Tim

 

[CanadianTSi]

With my Evo 3 at 20psi I get 21 degree's of timing with O2's of .94 at 6800 rpm.

 

[kpt4321]

This is a loaded question. There simply is no easy answer.

The optimal timing advance is the most advance you can run without knock retard or without power loss occuring. That can be anywhere from 15 to 30 degrees of advance, probably in the low 20's for your setup. However, the only way to find out for yourself is to tune the car.

As for O2 voltages, you simply can't use them to tune I am afraid. The stock narrowband O2 sensor is almost useless for tuning, if you want more information do a search about it, it has been discussed before. The short answer is you can't depend on it's numbers, and if you want to know AFR you need to use a wideband.

 

[kyle h.]

I agree with the fellow above on this one. (of course)

average timing i've seen on a few setups with *minimal* mods like those u listed are around 18-24* WOT.

as for o2 readings. the standard narrow band o2 sensor is not tuning quality. i read anywhere from .82 to .86 nothing higher at WOT with zero knock and 19*+ timing advance.

most people will tell you around .9 is optimal, but some wont read that high, some will always read that high...etc...

 

[kpt4321]

average timing i've seen on a few setups with *minimal* mods like those u listed are around 18-24* WOT.

Just keep in mind that 1g's and 2g's will be way different.

as for o2 readings. the standard narrow band o2 sensor is not tuning quality. i read anywhere from .82 to .86 nothing higher at WOT with zero knock and 19*+ timing advance.

most people will tell you around .9 is optimal, but some wont read that high, some will always read that high...etc...

In my car, when the O2 sensor is warm but not hot (coming off cruise) about 0.86V is ~11.0:1 AFR. That's a 93 AWD.

However, O2 sensor voltage varier by car, by model year, by generation, by temperature, etc. Therefore, in the end, it's hard to make a judgement based on it.

You generally will get a feel for what your car likes, and then you can use it as a secondary reference from there.