So I noticed this new WR run (even though it's 8 years old) has a potentially useful trick in it. Skip to 1:57 and look at how he's shifting to retain booster speed. It could just be a visual trick but I'm not sure, could be something interesting. I have no idea where it could be useful but I'm going to attempt it on the US cartridge.

(Current WR?)

I can confirm it works on the US version as well. And it does appear to retain the higher speed while allowing for regular turning, could be very useful if applied correctly.

Yeah, the trick is pretty much the same as "gear gacha" in the original OutRun. It's absolutely allowed so go ahead!

Is there a static # to the times you can shift before the car loses speed? There's times where it seems like I can keep it at 330 km/h for what feels like a very long time and others where you stop slowing down within 5 shifts.

Also I've seen from the runs I've been doing that if you shift while boosting on tarmac, you slow down to 330km/h and while off track, most of the time you get down to 314km/h. There also seems to be places where attempting gear gacha just doesn't work. I think it has to do with bushes that are placed off track but I haven't tested that theory.

Upon further investigation I believe the "speed" number, while displaying as higher, isn't actually making you move any faster. In fact it's more beneficial to get it down to 580 more quickly because that is the only number that passes the check for the game allowing you to build turbo. Basically, it seems useless, but I could be wrong, I didn't test it very thoroughly.