STEP 1, DIY Horsepower

1. Make ONE hole in the air box underneath the air filter , overall diameter no more than 35mm or remove the outside snorkel and increase the hole on the outside like these pictures.



Power curve below, and you will notice it too, especially the new induction noise. :)

Airbox BHP

Horsepower before and after, using a GTS1000 with a standard exhaust fitted (catalyst).

STEP 2, DIY Horsepower+

For the second stage you can get a little more horsepower by modifying the exhaust (removing the catalyst) and fit a less restrictive silencer (green curves)

STEP 3, DIY Horsepower++

Third stage
, even more horsepower (see red curve)

1. Do the STEP 1 & 2 mods, then remove the “snorkels” from inside the air box (as shown)

Do not make the hole under the filter this big, because it only needs to be ONE at Ø35mm maximum, like you did in the first stage.
This was the first air box I modded, so the hole is too big, and it was before I knew better.

Enjoy your new horsepower (red curve), and look at the difference from the original (bottom curve). :)

This is what I did on the later bike, I removed the inlet snorkel on the outside, and made a new hole, and fitted a rubber off a Kawasaki ZXR, as you can see below.



You can use any filter, OEM K&N or DIY! This is a DIY version