I drove the drag moonhawk in a straight line and I noticed that the coolant never overheated and even started to cool down once it started reaching higher speeds and it took about 6 and a half miles before any damage was caused which seems like quite a while for a dragster, is it realistic or not?
It is kinda realistic I suppose.. Due to the fact that the drag version has a heavily modified radiator. So I guess it is semi realistic.. I don't know much about drag cars but should be enough to say that..
It is somewhat realistic, but the devs said that they didn't want the cars to overheat too quickly so it takes more time for an engine to truly overheat. Not every car can overheat rapidly either. Certain cars either don't have thermal codes like off-sites or out-of-date mods like the the CR-X. Others might have engines that are just difficult to overheat, such as the Pigeon's underpowered diesel engine.
But a dragster should probably be generating a lot of heat... but if you just floor it the coolant only starts heating up briefly then the temperature goes back down, the only reason it even overheats is because of the oil(and that overheats pretty slowly too) otherwise it would be able to drive full throttle until it runs out of gas, I feel like the drag radiators work so well that if you just change the tires and suspension you would be able to drive them around a track with no problem. I could see that becoming a problem when career mode is added because they would be able to do most races or whatever else needs to be done as long as it isn't loo long and they have way more power than all the other engines without any turbo lag.
It's the radiator, the drag version uses a special radiator just for it. Removing or changing the radiator will make the coolant temperature rapidly rise to to 130°. It takes time for the oil to overheat, it's like that on every car.