I have a 2021 Corolla, and a time machine. How far back must I go to win the Indy 500?

[Robot_Arm]

@Tired_and_Cranky

It looks like you might have a good chance to beat George Robson in 1946 , who averaged only 114.82 mph. By 1950, the average speed was 124, including pit stops, etc. and I think your Corolla would be pretty well outclassed.

I’m pretty sure these average speeds include laps that are run under caution. If Robson averaged 114.82 over the whole race, some portion of the race was run under a yellow flag behind the pace car, at maybe 70 or 80 mph. (I don’t know how fast the pace car went in the 1940s.) When the green flag came out, he must have been going 130 or so, in order to bring his average up to 114.

Now imagine the OP is in that race with his Corolla. When the yellow flag is out, he’s stuck behind the pace car along with everyone else. Then, when the green flag comes out, he’ll never be able to keep up with the other cars at race pace

[penultima_thule]

For every lap driven under yellow @ 70mph, he needed to be going @ 130mph under green for 6 laps to get the average back to 114.8mph.

[Robot_Arm]

Regardless of the exact math, our Corolla will have to keep pace with the other cars during green-flag laps. According to Wikipedia, the qualifying speed for the pole in 1946 was 126.471 mph. That was for an ideal, four-lap run, but race speeds above 120 were probably possible. I had to go all the way back to 1931 to get a pole speed of 112.796; our Corolla might be able to keep up with that.

@Dr.Strangelove

Wikipedia says that 1925 was the first time anyone averaged over 100 mph. Other sources say that the curves at Indianapolis are 250 m in radius. The Corolla can do about ~0.75 g on the skidpad; if we derate this to 0.65 g, we find that the Corolla should be able to do 90 mph around the turns–and that’s without taking the bank into account. So it would not surprise me if it could do 100 mph, or close to it, through the turns.

That 250m radius for the curves, is that for the inside edge of the track? The actual racing line through the corners at Indy would have a much larger radius, so the speed will be higher than your calculations.

[TriPolar]

Is there something preventing modification of the Corolla? The rest of those cars aren’t stock models. I’m sure that engine can be juiced up to produce more HP and run hot for just 500 miles and do better than 120MPH. That engine without modification could run seriously low on oil and still go for 500 miles, that kind of engineering didn’t exist back in the 50s. With better wheels, tires, and suspension the turns won’t be a problem. The current body is probably more aerodynamic than the competition so it could be improved but you could just leave it as is. And I doubt the competition can get as far on a gallon of fuel as the Corolla at any speed.

[Tired_and_Cranky]

@Robot_Arm

I’m pretty sure these average speeds include laps that are run under caution.

Good point. I mentioned pit stops but not yellow flags which would also be a real issue.

@Robot_Arm

According to Wikipedia, the qualifying speed for the pole in 1946 was 126.471 mph. That was for an ideal, four-lap run, but race speeds above 120 were probably possible.

Another good point.

@TriPolar

Is there something preventing modification of the Corolla?

As asked, it’s an interesting interesting comparison of historical race car performance to today’s economy cars. Your alternative is a Ship of Theseus philosophy question that I wouldn’t have spent a moment pondering.