Auto trans on the track?
Been doing it for nine years, everywhere from Roebling Road to Sebring and many others.
First, please take note that my TTO crash in 2003 was certainly not due to a downshift by adding more power LOL
Second, the reason I do it is I'm too linear for shifting and heel and toe clutch management.
I can remember left foot is STOP and right foot is GO. Add shifting, throttle blipping and clutch actuation and I'd never learn to go around the track at all!
There were a few gotchas.
There needs to be a big enough trans cooler.
The torque converter needs to have a low enough stall speed and permit enough
oil circulation to avoid heat excess heat generation.
The trans needs to be modified to produce crisp shifting to minimize heat generation and also to make sure there's enough
oil flow to take advantage of the cooler.
After getting that right, the car can be run as hard as possible for thirty minute sessions at Sebring without any overheating problems with the trans.
The absence of shifting has a huge advantage for me: I can concentrate on the correct racing line, where to brake and accelerate and yes(!) even passing.
It was a long learning curve with the hardware because I could not find precedent and had to work out each item myself. It took four transmissions, three torque converters and a lot of hard nosed negotiation with vendors before it came together.
There is very little experience available in road racing as most cars have engines that may be a bit small for the job. There is some added hp loss compared with a stick shift; the big block doesn't seem to mind.
The most similar usage I've found is -GASP- mud trucks! They have large engines and often get used for a full tank of gas playing on the back 40 between trips to the race track. Anyone who builds a converter for mud trucks can probably build a successful version for road racing.
The biggest problem to date has been separating
experience from opinion.
(note to self: this separation can be problematic for all kinds of other car-related technical questions and even non-car related questions)
Most folks who have never done this have opinions that are incorrect. Even pros.
Case in point: I went to a recognized torque converter maker and asked for a very low stall speed converter, say about 1600 rpm lockup. The maker then proceeded to talk me out of it by opining (note: opinion, not experience, at the name brand professional level, sigh) that he could make a looser, low heat converter for me. It didn't work. Boiling trans fluid after ten minutes is a no-fun experience...
The mud truck guy nailed it on the first try.
In all, I find the auto trans car much easier and more pleasant to drive both at the track and on the street. Finally. Just put it in Drive and go do stuff! YMMV
Tom