Q: “What is your opinion on the frequently expressed dictum “trail brake until apex then back on throttle starting at the apex”?”
A: My opinion is that this dictum is total crap! About the only thing that I know of in performance and race driving that follows a “always do this” dictum is that there is nothing that always works! If someone tells you to always do something, run away and ignore what they just said. There are just about as many exceptions to messages like this as there are times when they work.
There are corners where you should release the brakes at the turn-in point, and therefore not trail brake at all; there are corners where you should trail brake far into the corner. There are corners where you should begin applying the throttle before the apex; there are corners where you should begin applying the throttle after the apex. And everything in between.
All of this depends on how well your car turns in, whether you’re focusing on exit speed more than entry, and track conditions.
I’ll also say that I have a hard time thinking of a corner where I’d want to trail brake all the way to the apex – and I’m a big proponent of the use of trail braking. The EoB (End-of-Braking, where you finish braking) is typically somewhere between the turn-in point and apex, but if you’re just finishing trail braking at the apex, I suspect your entry speed was too high and you’re in a bit of a “save it” mode.
Great answer! There is one more “always” statement that is correct: “There’s always more.”
If you are experiencing a lot of understeer will you get through a corner quicker if you trail it in, applying throttle later, or simply allowing the car to push with early throttle?
Trail braking more into a corner often helps reduce understeer, so that’s one option. The reason is helps is because it keeps load on the front tires. But that load can also overwork the front tires, so there are times where you need to release the brakes earlier to give grip to the front tires for turning. As for the throttle, if you get the trail braking right it won’t result in you applying it any later – if you use the brake release to help turn or rotate the car, then you’ll be reducing the understeer, and even get to throttle sooner.