Well it can be done over to the left but sometimes the BR won't register/complete itself because of the wall on the left-hand side. You can skip over the wall for the BR which is nice and fast but more often than not you'll end up facing the other direction.
There's also a doubleBR going into the tunnel (after the boost) but it's more trouble than it's worth and has to be done really well in order to get even a tiny advantage over your ghost. But it's there if you want it :+