Do you think an automatic transmission would "fry up" in a NASCAR race car?

May be...

Quicker than a scab at a Teamster strike.

no i dont think so the technology today they would figure something out

No, not really.
It would just do all the shifting for the drivers.
I've floored an automatic...it revs hard but it still shifts.

But I'm far from mechanically inclined, so don't hold me to that.

I think that a automatic would fry.Yes

You could add a big enough cooler and beef up the parts and pieces to handle it. Many really high horsepower drag cars use automatics without any trouble. There would be a really big learning curve though.

Do you think the heat and high r.p.m.'s would "fry" an automatic transmission in a NASCAR race car? And, would it cause more failures?

High rpm? A NASCAR typically revs at about 9500rpm on the big super-speedways. That's minuscule compared with say F1 which is limited to 19,000rpm.

Torque and stress more than anything else kills transmissions, and there are trucks which produce more torque than NASCARs.

So, NO. I think a "fry up" is a silly suggestion.

An automatic would work if it had a lockup converter strong enough to handle the power. Torque converter slippage is what makes the heat in an automatic. A drag car heats the fluid tremendously in 7 to 10 seconds. There is no way you can race for extended periods with a torque convertor.

It would have more power losses than the manual they use now though because of the oil pump in the automatic. This would reduce speeds.

Nascar is not going to allow any changes. It would just make more work for the tech crews and cost the teams more money.

If they can make an automatic transmission strong enough to use in an 18 wheeler to haul 80,000 pounds of goods cross country then they can make an automatic transmission strong enough to use in a race car. Just any transmission would not be capable. Also you would have to reroute the headers so as to keep the heat away from the transmission. In a road course it would be awesome because it would allow the driver to focus on working the steering wheel and the gas pedal. On a larger track however ... like Talladega and Daytona .... and also some tracks like Texas and Atlanta (as was stated by Beth) ... there would be some internal losses.

Every transmission suffers internal power losses. Automatics are worse.sprint trio 650