So today I went out for a couple of dyno pulls and on the first run the operator noticed the average AFR with the stock tune was 13.8 and we were like wtf?!
That run logged 226hp/229tq. He asked how long its been since I cleaned the MAF and I haven't since I've owned the truck. I pulled the MAF and we cleaned it and on the second run still with the stock tune it made 236hp/243tq.
Pretty cheap little power adder I thought lol.

 

or just custom tune it and turn off the maf.

Good tip for those running a MAF. Everyone changes filters and such but probably don't think about cleaning the maf sensor.

 

Yeah this guy was saying its a big problem especially with wet CAI setups.
I've kicked around the idea of running a SD Tune, but don't want to retune everytime the weather changes. I've definitely noticed better response in SD though.
I also found out that my "tune" needs work...picked up a whopping 1rwhp lol.

 

good advice, so if the operator was like wtf with a 13.8 afr where did he tune it 12.8?

 

Well heck yeah! You know all LS motors run best at 12.8 afr...lol

Actually I like to see the afr around 12.6 to 12.7 around peak torque and lean it out on the top side, usually to about 13.1 or 13.2. Some like richer some like a little leaner. Mine likes a little leaner on the top side.

Another thing to think about with the dirty maf is that the spark tables are based on grams/cyl airflow so if you are reading lower airflow you may be in a higher timing area of the map then where it was tuned to run at wot, this may get you some knock retard.

 

I had PE set for 12.6 across the board, logged average was 12.4...not too shabby for NB only street tuning I thought.

 

Nah its not, what were your o2's at? About 900 mv?

 

Right around there yeah.
Not to get too far off topic, but I'm pretty sure my method of tuning spark, i.e. adding until KR is encountered, was flawed. 37 degrees at WOT is too much.
Back to the ol drawing board lol.

 

You shouldnt need more than mid 20's to be honest, I wouldn't think...

 

what shop did you go to? aps?