How significant does acceleration affect fuel distribution and HP?

[Anthony]

I was wondering about all this talk about dyno HP, but it's not a true enviroment of racing, and one of these multiple aspects involves G-force, and its affect on fuel distribution in the intake manifold. I was told that with NASCAR, when the cars are under high cornering G-force, there can/is substantial alterations in fuel distribution, which I would think affect HP.

With drag racing in a normally aspirated car, , with acceleration, there is obviously some G-force with acceleration. In a 11 sec 1/4 mile car, would there be significant fuel distribution changes that occur as opposed with running the engine on a dyno? Is there a difference between single and dual plane intakes?

[BossCER]

I'm not too sure that there is significant fuel distribution problems w/ an 11 sec. carbuerated car, but it does make a pretty good argument for port fuel injection if in fact there is significant power loss.

[Anthony]

Originally Posted by BossCER

I'm not too sure that there is significant fuel distribution problems w/ an 11 sec. carbuerated car, but it does make a pretty good argument for port fuel injection if in fact there is significant power loss.

And if not an 11 sec car, what about a 10 sec, 9 sec, etc.

[olddog]

I don't know about the atomized fuel after the carb, but I can tell you it can cause problems in the carb fuel bowl. Under large G forces the fuel can all run to one side of the bowl and uncover the jets, and it results in fuel starvation. Some carbs have baffles to prevent this - other solutions as well.

At the London car show last year there was a fellow that was having this problem. He would launch and the engine would stumble bad. Second gear was a slight stumble, and then it was ok. He ran over and over again. I wanted to suggest he try raising the float level, but never got the chance.