gas tank fullness

[Maroon 6.2L SS]

I was just wondering how much gas everyone keeps in their tank when drag racing their camaros. Yesterday when I was at the strip, for only the second time, I had 1/8th tank of gas when doing some runs. I noticed (with all things being equal before launching) that my 60' and E/T were down. Last time I had a 1/4 tank of gas in my tank. It was also windy out 15-20mph cross wind the whole time. I'm wondering if with the car having less weight over the rear (due to less gas) as well as the high cross winds if that had an effect on traction? I know more gas will add weight to the car, but wouldn't it also help with having a little more weight over those rear tires to give it better traction??? So much to learn.

[Netraa]

I have always tried to keep 3/4 to a full tank of gas in the car. I did this for a couple of reasons, first, at 6 pounds to the gallon, 60 pounds for 10 gallons on a 4300 pound car is tiny. Second, I didn't want that tiny amount of gas sloshing away from the pickups on a hard launch and leaning out the engine with a sudden drop in fuel pressure. And Third, I didn't want the fuel pump running in air and getting hot, heating up the fuel.

I'm not sure about the third reason as this was a suggestion to me by another racer that makes sense at first blush but I never looked into how hot the fuel pump would get during a burnout and pass compared to normal driving.

Another thing that came into play was when I ran street stock at the circle track, we always installed baffles in our fuel cells to stop the gas from sloshing around if the car got loose, stepped out hard and then hooked just as hard starting a tank slapper. I'm not sure if the same thing can happen in our plastic fuel tanks, but it wasn't something I wanted to worry about.

Add to the fact that I mostly run bracket racing, I can compensate for the .07 performance loss due to the fuel weight.

[Maroon 6.2L SS]

Thanks Netraa, makes total sense!!! You know another thing I thought about is when you run the gas that low who knows the quality of it, with regards to everything else mixing in from the bottom of the tank vs everything else in the bottom of the tank being mixed in with a fuller tank of gas.

[Joe M 2012 2SS]

When my L99 had headers, cold air, exhaust, torque converter, and a tune, on MT ET Street R 18's, I always ran as little gas as possible to get my best time.

Less weight always gives better ET. Every 100 lbs. of weight reduction is a tenth.

You mentioned all things being equal, but having two separate days where track prep, DA, and wind are exactly the same, is very rare, if not impossible.

If your not using any type of forced induction, I'd run as little gas as you can before you go to the drag strip. Run as much air in your rear tires as you can and still hook up. The more pressure you run, the faster you go, due to less rolling resistance. Always run fronts as high as you can as well.

I wouldn't get so caught up in ET as I would reaction time. Running a good time is fun, but reaction time wins races.

[Pro Stock John]

Always have run mine at 1/4.

[stratman2SSRS]

1/4 tank