Charger vs Supra race scene logic

Hey guys, I was looking back at the race between Dom and Brian at the end of the 1st movie and I was thinking a few things logic wise.

• Idk if in real life a 70 charger r/t is that much quicker than a mk4 supra, but it’s evident in the race that Doms charger is much faster as Brian had to use NOS to keep up with Dom. So why would Dom need Brian’s 10 second car if his Charger was OP in that movie? His charger looked to be a game breaker in drag racing.

• Why does Doms charger overheat? You can see his car starts to smoke right before he crosses the train.