I bought a factory kit when I got the slip-ons and K&N, (big debate on the filter), and found it ran a little rich untill I got the full system on. I think the biggest plus to aftermarket pipes is in weight savings, those stock cans have to weigh close to 30 pounds!

 

What's the big debate about the K&N filter?

 

Maybe on the top end, but not the midrange. They pick up way more than 1hp in the mids. Mine, with Jardine race baffle (read: really loud) needed rejetting. The driveability was really bad. I've done just jets and shimmed the needles on other bikes, I knew this one was going to need more than that as soon as I rode it.

I'm running a Factory Pro Ti kit and I love it.

Jamie Daugherty
http://members.iquest.net/~daugherj

 

Again, what's the big debate about K&N filters?

 

The K&N is just hard to tune for. There's something about its flow characteristics that don't agree with the stock needles. You can tune it for idle and full throttle but its hard to tune in the midrange. Stock needles definitely don't get along with the K&N. The Factory Ti1.1 does fine for me. The needle profile is what matters, not so much their height.

 

Like Hawkrider said, a lot of people have a hard time getting them to run right with the K&N filter and it really doesn't seem to give a big benefit in hp. If it's tuned right there's only a slight gain but it does fill a little drop in the tourque curve. The main reason I use it is I live in a place that has lot's of dirt roads and I can just clean it and not replace it every time like an oem filter. I've seen a couple different Dyno sheets, some have a slight gain and some even a slight loss. I think it would probably do more for an engine that was built a little bit.