I'm a second slow. I blame the opening bumps. Practice mode Golden Fox CPU does wonders. GP mode Expert CPU not so much, apparently. Whether it's my technique or just that these CPU are not good bumping material is in question. I want Master unlocked!
Regardless, if anyone wants this .lsmv file that lasts only one lap, I'm making it available.
Also, those dirt patches reduce your turning rate, but only reduce speed by roughly 4 per frame. The electric rails don't affect turning rate, but reduces speed by 16 per frame. Your turning rate is still limited by your momentum, which usually can't be sped up reasonably, but the dirt patches are more than enough to let your momentum catch up with your facing.