Q: “For momentum cars like Spec Miata, is trail braking still an effective method for improving overall braking and speed out of the corner?”
A: Absolutely. Watch the brake lights of the fastest Spec Miata drivers, and you’ll see that they often don’t go out until after the turn-in. But, think about the brake zone, and think about moving the entire brake zone in. This way, you increase the length of the preceding straightway, and use trail braking to help rotate the car. The sooner you rotate the car and get it on the line you want, the sooner you can get back to full throttle.
When we think about why we use the brakes, we typically only think about using them to slow down, and to keep weight/load on the front tires when turning into a corner. But think about using the brakes to help you get to full throttle sooner. So, that’s why you do want to trail brake some amount in a Spec Miata – to help you get to full throttle sooner.
Finally, as I mentioned many of times, trail braking is not for all corners, but it is for many of them.