I have heard both of these are good filters, but which is better? and why? I live out in the country and drive dirt roads alot so I need one that traps dirt really well (just as good or better than stock).

 

they are both better than stock paper elements. I think the kool blue filters smaller particles but in my opinion they are close enough that its just a prefernce in color. I have only used the K&N but have friends who have used both without complaints from either.

 

cloth filters like k&n are higher flow but they let a small ammount more dirt through than a good paper filter, I read a study about this once, don't remember where though, if I run accross it again, I'll post it up here.

 

All the numbers I have seen show the cloth filters catch smaller particles than the paper, when the cloth filter is PROPERLY OILED. If they are not oiled enough, they will let some pretty large stuff through.

 

Not true, K&N now offers a "precharger" filter to use with their regular filter in dusty conditions. The OEM paper filter will filter out smaller dirt particles.....

 

I am not exactly sure what the precharger is, I know what the K&N "pre filter" is. If it is what I am thinking it is, They have been using those for years at the dirt track. Moroso has made those things forever. They catch the larger particles and keep the actual filter cleaner to keep its flow up. You change the pre-filter between every round. Wash them and the real filter when you get back to the race shop.

 

Marketing.
"Now that you have our filter would you like to buy a filter for it?"
or
"Now that you have our filtercharger, would you like a precharger?"

Version A makes it sound like the filter isn't good enough.
Version B makes it sound like the added filtering will increase power.

They have four prefilters that I've seen.
The precharger is a polyester wrap.
The airforce precleaner is a foam wrap.
The wetsuit is a silicone treated foam wrap.
The drycharger is a silicone treated polyester wrap.

The silicone treatment is for repelling water in marine applications.

There is another reason for them as well. K&N recommends that the prefilter be used in dusty environments. It isn't just to keep the filter clean. The dust will "wick" the oil out of the filter, thereby reducing it's ability to work.

At least that's the spin they put on it.

 

I have not used a Kool Blue filter before but i do know one thing that you can probably find this cheaper than the KN...performance wise i put an KN on my 360 and i instantly felt a better throttle response i don't know about power but i could tell the difference instanty over the paper filter it replaced

 

Here are some dyno test:


http://www.az-zbum.com/dyno.results.2003.11.12.shtml

 

I hate to say it, but I believe the Fram "Air Hog" is better than both of them. I dont like Fram, as a rule.