My Thumper inspired dominator....

worked flawless in it's first time out at dragway 42 this weekend,had it hooked up to the wide band and it is running leaner than the 3 circuit did by a good margin but still appears to be a little fat right after the starting line hit and all the way down track with the wide band showing in the 11.5 range, need to get it in the 13.0to13.5 range, bumping the high speed bleed from a 26 to a 28 helped so I am going to drop the main jettingand the PVCR a few numbers and go out to the local track and give it another test session in the next few weeks so I can be ready for Monster Mopar at Norwalk next month, thanks Dom I think it just a few steps away from total success, next is toss the 3 circuit to 2 circuit conversion carb on and dial it in too,

Dominic seems to be getting pretty good at this stuff.

Cool man and great news and ya, I'd rather be 11.5 than 15.5 for sure and it WILL start to shine when leaned out............

Do not chase Air Fuel Numbers!! Go by what the engine tells you when it's happy. The Air Fuel Number is just for reference for when you find the best performance tune.

Exactly, a directional tuning aid then it is what it is BUT, without one you never REALLY know where you're at and they are eye opening when tuning the 4 circuits on the street........idle, transition, cruise and WFO............

What Steff said. Don't chase AFR chase ET and MPH AFR is just a reference/target once you get to the best ET and MPH. One issue I see all the time helping people with racepacks is they are chasing the "ideal" number for a given channel, ignoring what the time slip says. MPH is still the barometer to measure by. There is NO "magic number" to chase. Every combo will want something different, even different fuels have different stioch numbers. FWIW if the heads up car was at 11.5 it would be pretty damn close for us where is makes max power/best MPH. Just one example.


AS for being fat at the hit its pretty typical, especially in a car with a brake. Even foot braking you have the pump shot that will spike it fat at the hit, its not unusual. You can help that by adding timing at the hit to help burn that excess fuel. But chase numbers on the slip not numbers on a gauge!

So true about the fuels and different needs then the mods to the carb(s) to get the curve set as needed..........fun chit...........

I know the wide band is a tuning aid and is not a end all be all iron clad deal, but by using it I can make changes and see what it does and how the car reacts to it by watching the time slip's also, if by leaning it out some and it slow's or mph drops down,then I know I went the wrong way and it actually likes a little more fuel than I thought,and vise versa, I did pull a plug and they have colored some but it is a lighter grey than ever before and the collectors are lighter in color than before so to me that is a plus, the biggest thing I was happy about, was with Dom's help and guidence I never had the first hiccup, that just made my job even easier because I am not chasing a gremlin while trying to find the tune.

Thank you sir and do what YOU want and get the results that get you the best time slip from the 60 on out.........

Al, the numbers so far are just a baseline to get things going, every individual motor has it's own "ideal" number and I am just starting the process of finding mine but I will be using "time slip tuning" as my primary information, my next purchase will be a weather station to help keep track of the conditions

Time slip,(use all of the measurements) spark plug and weather stations are your friend, especially on jetting, timing and spark plug heat range

Data is always your friend. But don't look passed the basics as well. I see it all the time helping people who are more worried about what the racepack says rather than listening to what the car is telling them. That was my point.

Couldn't agree more and I too am guilty as charged........

I would guess every carb was phat at Quaker City this weekend since the air was rarely below 3000ft. We saw 3900 on Sunday.

If you have a smart phone try Dr. Dial-In from the appstore. You can lookup the tracks closest airport weather station and use that. Its pretty darn accurate. I hope I don't regret sharing my super secret tips.

Google is your friend. A number of density altitude calculators on the web for free. All you need is your tracks altitude and use current conditions from the nearest Accuweather site.
Humidity, temp, baronetric pressure. All those figures show up when you hit current conditions on Accuweather.
Use it all the time.... one i use is dragtimes. Quick and easy

And the way I was sweating my butt off I was feeling pretty phat my darned self, lol,, and yes Sunday was by far the worse.