The Phakisa circuit, a stand-alone facility near Welkom in the South African gold fields, is a flat and frequently dusty track, ringed by a speed bowl designed for CART-style car racing.

Not used as a venue for pre-season testing, it always throws up some peculiarities come race weekend and has a consistent reputation of featuring a slippery surface due to the dusty environment.

More than most tracks, the key to a quick lap time at Welkom is good machine balance, with a harmonious relationship of chassis and engine, allied to a keen tyre choice for the prevailing conditions.

Always bumpy, the low change in gradient over the lap distance of 4.242 kilometres is a factor in suspension set-up. The front and rear suspension needs enough pliability to handle the staccato bumps at full lean, but enough firmness during acceleration to keep the rear tyre in contact with the tarmac at all times, thus preventing understeer on the exit.

Softer springing and damping rates are generally the starting point for the Phakisa set-up, moving progressively firmer as the lap times drop and the work done by the suspension becomes more demanding.

The most significant factor affecting the performance of the engine is the relatively high altitude in that part of South Africa. The thinner air robs any engine of outright power, due to the decreased density of the incoming fuel/air mixture and thus the lower energy yield of each combustion cycle.

With all MotoGP machines producing comfortably over 200bhp at present, this may be less of a factor across the board than it may at first appear. Fast work in qualifying, and reference to data from previous seasons, will nonetheless be required to make the necessary fuelling adjustments to the M1 in preparation for raceday.

 

Comments

Loading Comments...