I am not sure I understand how you are using the data from the AFR. I can see using it during test and tune to get the carb's jetted correctly, you are running dual carbs, I think most NSS Mopars must run dual carbs or if 1 carb it is an AFB per the rules. But the way I am reading your post you are checking the afr every run and rejetting the carbs after each run? Is this correct? Just trying to understand. I run my carbs on the lean side, one look at the weather station and I can tell how the car will respond thru out the day. I haven't touched the jetting in several years and my motor is 13+ to1 compression. I guess I've been lucky

How to find out whether you're illegal: you beat one of their friends.

nss guy: I have found jetting can vary as much as 4 jet sizes in the fall weather and 2 to 3 in spring - all during one race day.

Lets say you like to run at 13.1 to 13.5 and your at a Da of 700 ft with 60 grains of water and 58 degrees, temp change with north wind hits about 3pm, by 9 pm you at -350 ft, 20 grains of water 40n degrees and gained a full number in barometric pressure- thats 3 to 4 jet sizes to fully use that wonderful air , its 2 jet sizes to just be " safe lean".

Yes, i can get my data during test and tune or pre qualify/declare.

On other cars, not Nss, fast brackets and up, your watching weather and changing formulas constantly - every hundredth ( thousands even) matters.
On the dyno we have found even slight jetting, bleed changes make usable hp differences.

Last year we were sorting out a nss car that had a lot of changes made looking to hit 6.41"s - and we made it to .37.
I did not realize one could have the Afr gauge, but not use it after declaring.
That was brought to my attention and i just sought better clarity this year- its not a problem.

But yes, in brackets or straight index races i'm looking at data every run and watching weather changes , track temp changes, tire temps etc.
I want to leave at the same engine /trans temp each run as close as possible as well.

but weather changes effect more than jetting, im always thinking about timing as well.
I'm in East Texas and our air gets really wet during the summer and can change quite a lot on some evenings/nights depending on where we are getting weather changes from.

The Rules are the rules and so we will abide them .

Are you running a fixed index or just dial in?
When I race index I adjust to the car not the carb to hit the index. Bracket racing whatever the weather station predicts along with my wag I put adjust the dial in and don't touch the car. Now if it's fastest car wins then yes make every change possible to get max performance. I usually only run my car flat out once in the spring just to see what it's capable of and then add ballast and 'detune' to race index and usually race it the same way in et bracket dial in races. Never thought of rejetting the carb to adjust to an index.

Several things,
The Nss car i help with is straight index, last year was a LOT of changes he wanted to make so, it was about chasing a number, tuning to get there etc.
This year his will be pretty much a piece of cake- though he doesn't like to run ballast.
On Grudge, i'm looking for all i can get.
New car will be bracket and some index stuff- whatever has a decent pay-out.
Dial in, run the dial - not a big deal .

Index shouldn't be a big deal either.
once we have car sorted, get some data to work with , none of it should be a big deal really, just have to watch the weather in spring and late fall, summer is pretty much just really hot, really humid - regular old "sucks to be na" racing weather- grin.

I don't know anyone down here racing for money thats not gathering data and using it.
Of course the guys on the bottle ,,,, well, they just adjust their formula.

BTW- BEAUTIFUL CAR, sweet leave.

I have to agree with Jamie. I don't touch the carbs or timing either. Once its close the gain/loss is minimal. I've been laughed at about changing 5lbs of ballast. That being said you can get pretty darn close to index. If we're off more than .01, we made a mistake.
Doug

I had no i8dea this would be such a wide subject.
Perhaps its the difference in the parts of the country and weather.
Everyone i know down here racing for money or pints towards real money are taking in a lot of data and using that data constantly- timing, afr/jetting, driveshaft speed, attitude, g forces, tire temps, track temps etc.
Most data is just date/place data to date- patterns emerge etc.
But yes, guys are working with timing and mixtures even in the freaking staging lanes if there was an oil down and weather shifted.
When 15 to 40 k is on the line, i don't see anyone taking their car for granted because they realize the others are not.

I have a friend that won 2 championships last year and they didn't run the same formulas two runs in a row more than a few times all year, was more critical in the fall of course.

I absolutely "get it" for NSS and yes, simple bracket racing and fairly stable weather- just dial in and drive, no big deal.

but if your racing a tight /quick idex and there is a hard weather shift, the guys that win down here are the guys that work to stay tight on the number.
Our air can change radically/quickly- other places are likely different.

If im running a money index and we get a big thunderstorm stoppage ( pop up storm) and then track is cleared to restart- im gonna be watching air density hard, water grains hard- only way i know of to get back whats lost is with timing and air/fuel- exception would be if we are running ballast to "slow down" , then we could trim that.

NSS - we are adhering to those rules to a tee.