alright thanks guys. i guess when it comes time to get a new filter i'll go with a k&n or bmc street. whichever i can find a better deal on
also just got done putting my grills and air duct tubes on. now i need to get a threaded rubber so i can put my covers on lol.

 

u delete the upper resonators?

you could also cut open the bottom but with ur "dust" problem idk if u really want the possible intake of more dust.....

 

just the little rubber thing where my tube covers screw into the tank lol

 

Sorry to resurrect such an old thread, but I was hoping for a little more clarification on these aftermarket air filters, I see some positive responses in previous posts, but I was wondering if there were any dyno runs to back those up?

In my experience of dyno testing K&N filters most of the time they actually hurt the performance of the engine rather than help it. I actually wrote an article about it here

ROGUE RC51 Airfilter questions page


Ultimately I have a road going 600F4i project I am working on currently and am looking for validation from others that an aftermarket air filter is actually beneficial for performance enhancement rather than simple hearsay or bull**** that is prevalent on so many of these forums. If I have to I will put it on the dyno and test it myself, but I'm really hoping I don't have to go that far as I just don't really have the time for it currently even with the dyno sitting just 50 feet from my desk nor do I want to purchase the filters just to find out they like so many others are detrimental to the performance.

 

Personally, I'd love to see the dyno numbers...

 

you should do it yourself, but custom tune both stock air filter and aftermarket air filter, and sell your results and study to a magazine.
i think thats the only proof you are going to find, unless someone beat you to it.
just looking at things it seems they allow more air flow, but im not sure if that can be naturally aspirated, but if it can, then yeah, why not throw a bit more fuel in, boom more power.

 

There are tons and tons of dyno's of air filters for the f4i out there, and every one of them shows it does nothing. No power, no change in a/f ratio's, nothing. If the dyno's tested low enough I'd imagine a pretty good torque loss under 5k-6k from the k&n design as its just a flat filter, no airflow managment plates like the stocker has. I love K&N, and use them on every vehicle I own except my f4i.

 

Thank you for the info. No change is actually a good thing for the most part. It is nice to know they do not negatively affect the performance like what happens in so many other models of sportbikes. At the very least the argument that the filters are re-useable after being cleaned will still hold up I just did not want to install one only to find out it caused a dip in the performance or caused a stutter at a specific rpm etc. For the record I will be installing a BMC street filter. Based on the info above in that the filters do not really alter the A/F ratio I will not be dyno tuning the bike again, but if a problem with the filter install does arise I will certainly report back here.

 

Well unfortunately I don't have a before dyno, but I just got my F4 rejetted and I put a BMC race filter in it so I can give you that # even though I don't have a comparison.

 

No worries bro, from what I have read on the subject both here and other sources on the web I am willing to give this a shot on the F4i. I'm a tuner, suspension tech, test rider & instructor which combined makes me pretty astute when it comes to discerning differences in performance that most riders don't even notice let alone have a chance to dismiss. If it doesn't feel right I'll be the first one back here spouting off