Getting hot on the highway with the AC on.

PredaFran said

that's not how cooling works. water doesn't work like that it will always be picking up and shedding heat through the radiator. you can either circulate it slowly so the water stays longer, which can cause centralized boiling which will create hotspots, or you can make it pass through the radiator more times in the same amount of time, which is what using a bigger water pump does. it's just an old tale like cars liking exhaust backpressure.

Click to expand...

I guess I didn't word that very well, and if you think the time the water spends in the radiator makes no difference, it's very easy to test.

Look at at it this way, the water is moving at a fixed rate because the thermostat is the smallest port the water goes through, that will control the amount of water even at different RPM's. It will change some but it will max out even with higher pressure.

If you had a 20" single core rad, the water moving through it will be X what ever that is, but the water will move pretty fast through the rad.

Now put in a 26" 3 core, now you have more surface area and a lot more cores so the water will move a lot slower and will loose more heat not only because the rad is bigger but the water spends more time in it to shed the heat.

Also I have straight drag pipes on my Harley and with putting a small restrictor in the pipe it runs a lot better, so yea it likes a little backpressure.