We have tested many velocity stacks over the years on the ZX6’s. These stacks have always made the best power. We see a much soother power delivery, more peak power, and a much flatter torque curve too.
2019+ ZX636 +4 HP peak, +8 HP at 14,500 RPMS.
2009 ZX6 3+ HP Peak
These stacks outperform the common 09 stack swap by a LOT. The 09 setup on a 636 gives up too much mid range.
