I don't have any older consoles, but sure. Racing games aren't my choice of genre (I can't drive well.) Tell me this, how does slowing down BEFORE a turn help when driving?
In a race, it helps with high speed turns with minimal understeer without sudden & drastic loss of speed, alongside chances of wheelspin, it's a bit less cool looking & complex than just power-sliding or drifting through every turn, but the payoff is very worth it.
The trick is to slow down JUST enough that you're fast but in control (aka, no understeer & wheelspin). That said, you also need to manage the speed well enough, you can gain a good boost after the turn, with only half, or even less than half, if you're skilled enough the speed sacrificed for the turn.
One more thing, if you do it as close as you can to the turn, without losing the speed & control, that also plays a drastic role in this technique. You can also combine it with the basic curb turn technique which is basically just about how you don't turn too wide at a turn, when you're just beside an opponent car, but try to stick as close to the curb of the turn as possible, cause the opponent will try to overtake you from between the opening between you & the curb that your wide turn gives them.
There's some other complex nuances too, like how every game has a different mechanics so this depends on their handling of their vehicles, or how this changes terrain to terrain, or how the cars & their higher levels also up the ante on you skill levels etc. But the gist of the technique remains the same, no matter the track, or the car/bike/truck.
It's actually a real life technique that legendary British F1 racer Jim Clark used &, in a way, even invented this technique. However, he almost never lost any speed at all, he took turns in almost the same speed as he drove.
Hell, this is actually a daily driving trick too, I use this all the time, but the speed at that time never goes past the fluctuation of 20-80 mph at best & the turns are forgiving unlike a race track.