[sean.cooper01]

Hey all, I just logged a 4th gear pull today and after looking it over, my AFR seems a little high, and my boost seems to be making 1psi less than requested.

2015 328i 8AT EWG
67k miles
1k miles on new NGK plugs gapped at .022
Intake, tune and muffler delete.
Log was smooth, no hiccups or lost of power felt.
I retuned it right before the log only to change burble settings.

LOG: https://datazap.me/u/seancooper01/da...4&tmax=6170.00

Any help with the AFR and boost difference is appreciated as well as anything else you guys see that is off!

[dfwF30bmw]

Only thing I see is your AFR of 12.6 or so with a catalytic still in place seems like you would damage or burn up the cat. I thought I read if you going to do the AWG or stage 2 you really need to have no cat.

[sean.cooper01]

Originally Posted by dfwF30bmw

Only thing I see is your AFR of 12.6 or so with a catalytic still in place seems like you would damage or burn up the cat. I thought I read if you going to do the AWG or stage 2 you really need to have no cat.

I'm only on BM3 Stage 1 93 OCT, they didn't require a downpipe for that tune.
Also, i read somewhere that the AFR should be in the 12's but towards the end of my pull the AFR went up to the 14's. I don't know if that is concerning or not.

[jkstyle834]

Originally Posted by sean.cooper01

I'm only on BM3 Stage 1 93 OCT, they didn't require a downpipe for that tune.
Also, i read somewhere that the AFR should be in the 12's but towards the end of my pull the AFR went up to the 14's. I don't know if that is concerning or not.

isn't it supposed to be at 14.7? isnt that nomimal?

[Knifeedge2k1]

Originally Posted by jkstyle834

isn't it supposed to be at 14.7? isnt that nomimal?

No

You don’t want far in the 14s if you’re running high power. The purpose of the extra fuel by running rich is to help cool the combustion chamber to prevent hot spots from detonating and to ensure complete “use” of available oxygen (oxygen reacts with everything)

If you’re running at low load 14.7 is indeed normal, if you’re running high loads upper 12s and lower 13s is entirely appropriate.

[jkstyle834]

Originally Posted by Knifeedge2k1

No

You don’t want far in the 14s if you’re running high power. The purpose of the extra fuel by running rich is to help cool the combustion chamber to prevent hot spots from detonating and to ensure complete “use” of available oxygen (oxygen reacts with everything)

If you’re running at low load 14.7 is indeed normal, if you’re running high loads upper 12s and lower 13s is entirely appropriate.

ah... i see... yea i do see that AFR going down when I floor it but stay around 14.69~14.7 when not accelerating.

[Knifeedge2k1]

it should be around 14.7 for anything less than like 50% throttle

above that it depends on the custom tune, there's little benefit to going TOO low, but definitely danger if you go too high