The stock velocity stacks for the BMW S62 are deficient. They are not quite the correct length and diameter, but their most egregious flaw is the flat-edged bellmouth, which materially disrupts and slows the velocity of incoming air. Our carbon fiber velocity stacks correct this and employ a 180-degree bellmouth. Combined with the correct dimensions, our velocity stacks showed a 22 whp increase on our naturally aspirated high output S62 engine on back to back sets of runs compared to the stock stacks on the same dyno, same engine, same day, same weather conditions. The sole difference was our velocity stacks. The design of our velocity stacks enables them to be used with the stock plenum without modification, but obviously work best with the Partee Racing S62 carbon fiber plenum. Made from pre-preg carbon fiber baked in an autoclave, then glued with MMA into billet flanges designed and made in our machine shop, and hand finished. Along with headers, the single biggest bang for your buck to increase wheel horsepower on a naturally aspirated BMW S62.
