I have been keeping a close eye on my AFR gauge an an concerned that I might be running lean....

Backround:
I recently installed:
TBE+test pipe
AMS CAI
UICP
LICP
AMS FMIC

I am running boost and wideband AFR gauge.
I am NOT tuned yet, (awaiting my appt).
I have not gone WOT only partial throttle and shifting at 4.5K MAX until the tune.

Question:

My wideband is showing an AFR that is usually between 11.8-12.5 under partial throttle, partial boost, at about 4K RPM (i never go WOT and try not to boost higher than 15psi)

I know that a 11.2:1 is ideal at redline, but would the mentioned AFRs be acceptable at the 4K RPM range (partial throttle, partial boost)? Or is this too lean?

Side note. It does appear that the higher I rev the richer it will get.

Also, gets much richer during shifts. (duh) haha

Any input here?

 

I would think that you're ok as long as you stick to part throttle like you have been. At lower rpm's and light throttle, you will be in closed loop anyway, and the ECU will automatically target 14.7 afr. If you always stayed under 3000 rpm's and didn't get too aggressive with the throttle, you'd probably stay in closed loop nearly all the time. Generally speaking, I try to get my AFR in the low 12's once boost gets above 10 psi, and quickly richen down to the 11's.

Since you mentioned you're getting tuned soon, just take it easy for now and you'll be fine.

 

thanks!

 

i ran with this mods for close to 40k miles and was still hitting like 9:1 afrs

 

The proper AFR is one that keeps the ignition timing high and the knock as close to 0 as possible. Each car is a bit different so the AFR's at redline change sometimes to meet those goals. I am fine with 11.5 to 11.7 AFR at WOT with my mods.

Just stay at part throttle until a tune is done.

 

Go WOT you got stock tune right? Not going hurt anything. I flash back just see how slow my car felt lol. But without WOT log seeing your AFR's who knows. But should be pig rich still man your not changing timing or anything so should knock no more than it did when it was stock. maybe less.

 

just out of curiosity, how did you manage to log a 9:1 AFR? My Bosch Sensor (and most others that I have seen, will peg the rich side at 10:1 and the lean at 20:1.

Glad to hear you didnt have any problems though!

 

evoscan

i may want to point out that i was also original factory flash... so i was pretty damn rich from the get go... however, i was also doing crazy rich numbers with my fuel pump relay being out.

i currently am set up like a few others in here to run in the 11.5 range

looks like everyone thinks youre good to go, but whatever makes you comfortable is what you should do. theres no harm in controlling how you drive til you know the car is set up how you want it.

 

+1.

 

+1 for that!

Which wideband you using? thanks for the reply!

 

You are running 11.5 AFR - what is your EGT temperature ?