Z-Tube is minimal, 1-2 HP maybe. Its biggest benefit is improved intake sound. The Rev-up Airbox will give you zero performance benefit, at least nothing measureable. Its benefit is also cosmetic, i.e. a tweak to the intake note. The spacer OTOH is a definte boost you'll feel almost everywhere in the power band, but especially from 3500+ to redline. But these 3 in concert really change the way the engine sounds and performs.
Quote:
Originally Posted by scrapiron7
I was expecting the additional weight of the battery cover to slow me down  |
It's a trade-off. The extra weight is countered by the improved airflow.
