Muffler positioning

As a newbie to racing should the angle of the muffler make any difference. Should it be level with the exhaust manifold? Pointed downwards at an angle or even pointed slightly at an upwards angle?
I should mention i’m using a rlv pipe exhaust.

Hi Martin. What engine package?

KT100 yamaha with wet clutch, senior heavy class.

Close to horizontal is good enough. Don’t think it makes much difference. Keep it from hitting the brake rotor and away from the plastic bumper. Drive and have a good time.