So this is my new purchase list to gain more low end torque. Ironman rear sprocket 43T, k&n air filter and KDX Snorkel. What number should I go for the countershaft sprocket 14/15? (80% city riding @20% off road) Cant got lower on rear sprocket because 43T is lowest ironman offers.

Thanks!

 

For serious trail riding, you can't beat a 13T.

 

larger on the rear & smaller on the front = more torque, lower top speed.

 

K&N filter in dusty silt, not good. Stay with foam. Otherwise the K&N flows.

If I didn't do off road I'd probably do some cutting on the air box, lid off, but I do ride off road and stay with the larger snorkel to keep mung and drool off the air filter.

 

My Can-am came with a K&N from the factory. It was a competition motocross bike and had 34 years on the original bore. K&N filters are fine. Haters gonna hate.

I run one on my KLX, and have since 08

 

No hater, just relaying the facts.

If they filter better than foam why does K&N make a foam sock to fit their air cleaners and recommend them for driving/riding in dusty conditions?



From K&N's own site...

"What is a K&N Airforce Air Filter Wrap?

The K&N Airforce Pre-CleanerŽ is a specially designed foam air filter wrap made to extend the service interval of your K&N Filtercharger when used in very dusty conditions. (my emphasis - MK)

Red colored pre-cleaner filter wraps are made from large, open cell foam that is oiled. They will stop 90% of the dirt (my emphasis - MK), yet only add a 2% restriction to the airflow of the filter. Our red colored Airforce Pre-Cleaners are designed to be cleaned with K&N Cleaner or soap and water then re-oiled with K&N air filter oil. These pre-cleaners are custom made to fit each application, and there are four universal cut-to-fit sizes available."

You think they didn't have a reason they made them?

Most all desert trucks run the Pre Chargers, AMA pro flat trackers run them whenever the track conditions are dusty. There IS a reason.

Virtually every single motocrosser is running foam filters at this point. There is a strong aftermarket of foam filters for MX and off road. You don't see K&N stickers on motocrossers very often if at all. I guarantee you if they would work better the riders would be running them.

So, again - no hater, just know what I'm talking about on this one.

 

It says right there that the pre filter is to extend the service interval in very dusty conditions. The same pre filter could be used over a foam filter with the same result. I have used them on two stroke and four stroke with no issues. Automobiles as well. Makes me wonder if you have any experience with them or just opinions.

 

As far as I know the foam filters are good when off roading where as pleated air filters are better on the streets? I could be wrong

 

Well for city riding will 14/43 do good, will a power/clutch wheelie work in 2nd gear? *No highway riding just city riding speed rage of 50Km/h to 70Km/h*

 

Used K&N on the street.

Why would I run a filter I felt would allow fine dirt into my engine - especially the two strokes I ran when racing - if I thought the foam was better?

Now the catch. I do research on the stuff I do to either find support or find lack of support and why. I did this AGAIN since I hadn't done this with the K&Ns lately. And what I found...


Dirt Rider Magazine's Jimmy Lewis, with some respectable racing and media chops, gave a good revie of the MX Xtreme. Best of all he gave more information and experience points. Problem still is no actual testing, but he's giving the same kind of evidence riders use against K&N. He experiences fine dirt on extremely dirty foam filters vs the K&N, others experience the reverse, but the possibility is it is poor installation and sealing for both. The harder plastic of the K&N can present an issue, but greasing the face of a foam filter and seating it may not be perfect either.

MXA Magazine gave a good review too, with a few minor issues, but not dealing with filtering.

So at this point I would change my thoughts to say properly installed the K&N is pretty much on par with the foam - if the foam filter is properly installed. I doubt the flow is a big deal for anyone other than a racer. Peak flow at peak rpm.

I really do question the claim of more low end. Low end is requiring less flow which both filters should easily allow, than the kind of flow required even at mid rpm. Is it more of a self-fulfilling prophecy than reality? If there was actual performance testing showing it I'd believe it. Thing is guys put on exhausts that actually cut mid and low range, then swear it gives more power because of the bit of a kick when the engine finally does hit the point where the power hits. Dyno runs show a drop in real power down lower, with the boost in HP up higher. Funny part is when the power is added over the power range sometimes the bike feels slower, in spite of showing real power increase over the range... but I digress.

I'm not seeing any serious clear testing on the filtration at this point other than some done for cars. Seems the main issue for any filter would be proper installation for sealing it.

At this point I am pretty much indifferent to foam or K&N. The K&N will last the longest if not damaged and is a bit more fragile, the foam is low cost to replace near 3 to 1 on price for sure. It is semi-indestructable when it comes to handling, but will degrade and eventually tear. Easier to carry a second oiled filter in a plastic bag. Flip the coin, consider handling, and how much coin is in the wallet.