[Taz]

As someone who's just had a Mountune 275 kit installed, I was wondering. Is it better to keep the end cap off the air filter? I've been told keeping it off improves performance.

 

[Toadster]

less restriction and more noise if you keep the cap off, but potential to suck in hotter air if it's warm under the hood... most likely it's about preference of tone

if you do a dyno test, the hood is "up" and open - so you don't get any heat soak with an open element

 

[juicyz]

The change will be so minor you wouldn't notice the difference. If you like the sound better with it off, keep it off else put it back on. If you have a snorkel, keeping it capped and closed is the "correct" way but still there likely won't be a notice at all.

 

[Taz]

Thanks for the info.