Tonight im going to race my car at the local 1/8th mile strip. It is very hot out 90 with 90% humidity.. Has anyone ever tried putting a bag of ice in the bottom of the airbox to cool down the air coming into the engine, do you think this would help much?

 

Never tried it. I have cooled down the manifold with a bag of ice though. I'm not sure if it really made a difference that day because I still ran a slow 16.1. Personally, I'll never run on hot days again. I'm wating until the fall to hit the track again.

 

There's no point. The surface area of the bag of ice, and the rate of air consumption wouldn't make any measurable gains. In order to get enough surface area for heat exchange, you'd need a heat exchanger like a rad or intercooler type exchanger, somewhere in the intake stream.

 

can't say if this is true or not. the two times i used ice on my intake and manifold, i ran my best two times. i'm sure there might have been other factors, but i ran .2-.3 slower when not using the bags of ice.

 

There's a huge difference between ice on the intake manifold and a bag of ice in the air filter box. You chilled the intake manifold, which is often very hot, and can affect performance by heating the intake charge, while the original poster is talking about cooling the intake charge.

 

What about connecting the stock air filter box to another larger box with dry ice (if you can get your hands on some). Theoretically, if the ice acts as a cold filter for the incoming intake air, it could lower your air intake temperature levels enough to notice a difference.

Remember, for every 10 degrees increase in intake temperature, you loose about 1% power, which is about 2 hp for our cars/ten degrees.

 

I've thought about that idea as well :P The problem with that is that dry ice is carbon dioxide, which the engine cannot use, and will actually act as a snuffer, as opposed to an oxidizer. So having the air go through the dry ice will sublimate the CO2 rather rapidly, which may even prevent the engine from running.

Dry ice is used in race applications, in formed chunks that sit over transmissions and engines in F1 cars. They do this because at the starts of races, without moving air, they overheat. That's why it isn't unusual to see a large white fogging chunk of fogging material fall out of F1 cars during the first lap.