Hey guys,

Got my wbo2 installed a few weeks ago and have a few questions. I noticed from YouTube videos and such others have more steady afr than I'm reading. I'm wondering if it's just because they have stock motors, injectors and cams, so since I have 1150 cc injectors, gsc s2 and a built block us that why my afr have more fluctuation?

For example at idle abs cruise the cat wants to be at 14.7, but it jumps between 13.5 and 15.5 and sometimes even gets to 16. For the most part it is at or just about 14.7 but the fluctuation I've been seeing from others is like 14.4-14.8 at idle and cruise.

At WOT my afr is consistently extra rich for safety I'm guessing... Looks to be between 10.8 and 11.3 with 25 psi. I was reading that the most power will be made at 12.5 afr... Isn't below 11 a little extra rich?

 

The fluctuations sound about normal if you've got a built motor with cams, etc.
You might need a tune if you haven't already got one.

 

I was reading that the most power will be made at 12.5 afr... Isn't below 11 a little extra rich?

Your right in you assessment, but the most power is made at 12.4-- on NA motors--turbo you going to have to be a little richer-- most tune to 11.5. to be safe.. Below 11, yes is very rich and a waste.

 

At WOT you could have it leaned out a bit, 11.5 flat is good to shoot for, 12.5 is ideal for NA motors.


The swings in AFR at idle/cruise are normal.

 

Thanks guys. The car was already tuned by strictly modified. I just wanted to make sure this was all normal.