For those of you street tuning your cars, what are some of your first instincts when it comes to reading a datalog?

For example


You see knock in the High RPMS....pull timing/add fuel/turn down boost (which is your reaction)

You see Knock in the Low RPMS....fluke/etc

You see a poor Air/fuel via onboard wideband....what do you do


Id like to see this turn into a kind of FAQ where as what a newer tuner should look for when they see common symtoms on thier datalog.

 

I'll start off by saying I'm no expert, by any means, but the first thing I address when tuning are the areas with the highest knock count. I drop the timing until the knock is gone all over the RPM range.

Then I work on getting the A/F where I want it to be at various load points.

Once the A/F is stable and there is still no knock I'll bump the timing back up 1* at a time until knock comes back, then back it off a degree or two from there.

Sounds simple enough but it takes a while to get the hang of it.

 

I am currently following this methodology:

1.) set boost to ~20-21psi, fuel pig rich (e.g. 10.0-10.5, aka stock )
2.) do some runs to make sure I have no knock
2a.) if there is knock, dial back the timing in the offending load cells
3.) fill up with racegas
3a) dial in the fuel map to hit 11.0 afr +/- .2 AFR at WOT, depeding on gear
4) fill up with pumpgas again and verify that there is no knock with the higher AFR
4a) if there is knock, dial back timing
5) add boost in ~1 psi increments and make sure there is no knock up to a maximum of 22-23 psi for 93 octane
6) now see about adding timing, if possible.

It's fairly time-consuming to do it this way, especially since I spend a lot of time analyzing logs and graphing them, but I'd rather be safe than sorry.

l8r)