Whats the difference if any ?



I know you can run a pre-rap on the 6637

I don't know if you can buy a pre-rap for the K&N

Can either be run with out a pre-rap ?

opinions please..

 

Well, yes you can run a pre-wrap but it is really going to choke the air flow on either filter. You coule purchase gauze wrap (bandage) and make 1 maybe 2 wraps worund the filter and have good air flow still, but for street use it would be unnecessary.

I would avoid oil impregnated filters. While they have their purpose in off-road applications, Ford/GM/Dodge all have “watch-out” bulletins where the oil has contaminated intake sensors. - they even have a training video for the techs on this (flatratetech.com) .

If you look at the flow data, WIX HP filters flow 98+% of K&N and have a much smoother flow post filter plus excellent filtering.

Do some research. Once you see the 6637 filter and how massive it is....
You'll understand. It's super easy and really works great. Google diy tymar or 6637 mod.

 

Yes you can run either without a pre-filter. I run mine with a prefilter that came with the kit I got from RiffRaff diesel. Works very well. The 6637 filter is 99% at stopping course dust...K&N is ??? IMHO your best bet is the 6637 for a PSD under 450-500rwhp.

 

i ordered the 6637 kit Friday from riff.. should be here by Tuesday..