Any correlation between fuel level and performance?

[fdjizm]

This is a weird question but one that makes me wonder.
I remember at least a handful of times where I was at the track with just below a half tank of gas, getting my best times and saying I wonder if I would have done better with below a 1/4 tank? ( due to weight) But I always remember getting to the track with slightly less thank a 1/4 tank of gas and not running my best times.

I am wondering if anyone had similar experiences or any technical input on fuel level vs performance? Besides the obvious weight reduction and assuming no traction issues.

 

[irishpwr46]

im thinking that with 1/4 tank, youre starving your system. the higher your fuel level, the more pressure being put on the inlet of the fuel pump.

 

[skwerl]

Less than 1/4 tank and your fuel temps will be higher as well. Fuel cools your fuel pump so less fluid means quicker heat transfer to the liquid.

 

[UltraKla$$ic]

All the octane sinks to the bottom..........Please move to TEKK...............

 

[travelers]

It comes down to weight and fuel temp.

 

[fdjizm]

im thinking that with 1/4 tank, youre starving your system. the higher your fuel level, the more pressure being put on the inlet of the fuel pump.

Less than 1/4 tank and your fuel temps will be higher as well. Fuel cools your fuel pump so less fluid means quicker heat transfer to the liquid.

It comes down to weight and fuel temp.

Hmm interesting, the fuel temp thing... I am wondering if too low a level causing sloshing that pisses the pump off.

 

[05stroker]

One other thing to consider, with 1/4 tank, how do you know it is all on the pump side of the tank? Remember, I starved mine with 3/8 of a tank. 4" on pass side and 1" on drivers side. Just FYI.

 

[fdjizm]

Hmm didn't think of that, makes sense.

 

[Newman]

I think it's when I have less that a 1/4 tank. When I WOT and shift to 2nd, it bogs so bad like the car shuts off, then gos back to normal WOT. I have no clue but that makes the most sense.

 

[Five Oh Brian]

I raced a couple weeks ago. Started with 1/4 tank and ended the day with 7 miles to empty. Ran the week before that with 1/2 tank. With no gas, ET's worsened by .15 second on average. However, trap speeds improved 1.5 to 2.0 mph. Very strange.

 

[s8v4o]

Since we have a returnless system would tank temps vary much with a 1/4 tank versus 1/2? With a return style system I could see that being a bigger factor since the pumps work at 100% all the time and returns that heated up fuel back to the tank but that's not the case with the returnless system.

The whole fuel starvation thing could be detected by datalogging all your fuel parameters AND AFR. Meanwhile the traction part could be observed by comparing your 60' with the different fuel levels. I think you have all the tools need to find out your answer if there is indeed a difference in performance between tank volume levels.

 

[UltraKla$$ic]

I guess on a good note, if you ran out of gas in a 3V, you could PUSH it just as fast down the 1320........no?

 

[firestang70]

Darren you have to at least burn fuel with your car before you post in this thread. Your car hasn't been past 7/8 yet.

 

[UltraKla$$ic]

Thread was moving as fast as a herd of turtles. Figgered I'd lite the wick on it. LOL!!!

 

[s8v4o]

Darren is just primping his car for the next guy when he trades it in on the next generation mustang. Just like he did with his last one.

 

[fdjizm]

^sad but true, hear that Darren.
drive that bitch!