I'm curious.... In your testing, was the first (boosted) attempt at braking your car effective at slowing it despite the full throttle? What about successive (unboosted) attempts?

It was quite a while ago the last time I tried this. And what are lunch breaks for if not some driving around? So I just gave it another shot in the Honda.

Starting at 70, I floored it. The first brake press was more effective than I remembered. I could slow down reasonably well, although not like normal. As the speed dropped to a down shift point for the automatic tranny, it became a bit harder to slow down. Which makes sense, as the engine moved up in its power band.

For the drained vacuum reserve, I started at 60, floored it, then pressed the brake several times. The brake pedal became very hard. When my speed hit 70, I started braking in earnest. I could slow the car a bit, but not a lot. It took a couple seconds to get down to 60. Again, I think I'd be a bit more effective if I could have had both feet on the brake. The down shift was a bit unnerving as the engine started generating a bit more power. But again, I could slow the car.

If I didn't care about the car and were willing to burn through some brakes, I'd carry the testing further. I don't know if I could get to a full stop against the full throttle with no brake assist.

--Peter