Front Brake Duct Hose Size
 

What is the best brake duct hose size when it comes to fitting and routing? 2.5" or 3". Track days

The Stillen kit is 2" hose. It's not too hard to route around the washer reservoir. 3" is a challenge around the washer reservoir. You have to cut the inner fender liners on both sides too.

Stillen Kit was 2".

MY kit was 3"

You'll have more difficulty routing the 3" hose to the rotor, but more air = gooder.

I have 3 inch in mine. You won't be able to completely lock you wheel because it will hit the hose but how often would you actually do a complete turn on the track? 3inch = better.