Secondary runners

[rendyx]

Okay, I keep hearing about them, but what are they, and where are they?

 

[twr]

They are the short runners (snakes) on the intake.

 

[rendyx]

Sweet, I just have always known only a little about them, so I thought I'd finally ask.

 

[pete c]

ever wonder why the intake looks like it belongs on a v-12? It's cause them clever yamaha engineers realized that short runners work good at hi-rpms and long runners work better down low, so they gave each cylinder one of each.

 

[Mike Kopstain]

For a little more detailed explanation:

Basic intake knowledge is that the longer & skinnier the runner, the more torque you will get down low in the RPM's, and the shorter and fatter the runner, the more air you get up high when you need it. The problem is that you either have one or the other, but most manufacturers settle middle of the road for an intake that will provide decent power throughout the whole power band. Yamaha decided that this was a no go and decided to include the best of both worlds in their new engine. The short/ fat runners open up at about 4000 rpm, which gives your car Two (count em' two!) torque peaks.

It's a beautiful design. Probably more detailed than you wanted, but I'm bored.