Air filter
- Thread starter 4zracing
- Start date
Shorttrackthing
Member
UNI stage 2 air filter, best ever, use a foam filter, it will filter it way better and your carburator will be clean, i used a bag prefilter and my carburator was pretty dusty not too bad but still, that's why you use a foam filter, lube it also, only needs to be sprayed twice then squeeze the access out, then let er rip. Note every race wash the foam filter im dawn or simple green and water and then squeeze the water out of it and let it Dry, then relube it
WALKER IS ABSOLUTLEY THE BEST YOU CAN GET IT SHOWS UP ON THE DYNO, AND IF YOU WASH AND OIL PROPERLY THEY WILL LAST.
mike97760
Site Supporter
If you were using a "bag" prefilter over your Uni air filter and you were getting dust in the carb, doesn't that disqualify the Uni from being best ever filter?
Shorttrackthing
Member
I am using a uni foam filter, plus the old filter was an ARC cotton filter with a bag prefilter, foam filters lubed lightly work rhe best plus no dirt on the carb with my uni foam air filter, but with the bag air filter and arc air filter the carb was dirty
SoCo Tire Treatments
Moderator
K&N and the Walker filters are very good filters, but if you use the cheap filters and change them out very often they are fine as well.
Pre filter of some type is a must IMO and change them out often as well.
Pre filter of some type is a must IMO and change them out often as well.
CarlsonMotorsports
Site Supporter
I wrote an article many years ago testing air filters on our Superflow flow bench. It "may" have been published in National Kart News back in the day...I don't honestly remember and don't have time to look for it right now. But to summarize the article/point:
The power difference is often in the flange and the transition area where the rubber mold meets the pleated filter.
If you compare a standard 3 1/2" X 4" filter from one brand to the next (new) there will be very little difference to one that is 3 1/2" X 6" or 8." All of the air flow comes in at or below 2" from the flange. Simple test that we did at a trade show years ago when super tall filters were all the rage for flatheads...I think it was Frank Bondatti who was there selling tall filters as fast as he could take the money and hand racers their new filters. Not a knock on Bondatti, I'm sure he was told those filters were better. We had Tom from Superflow in our booth with our new SF60 so we bought one of the tall filters and started testing right there at the show. Take one of those tall filters and draw a ziplok bag down around it. The airflow doesn't change one bit until you get within 2" of the base of the filter.
So the next thought is to increase diameter and leave the height short. Ok, but there's a limit to how much that helps as well. Now comes the animal and clone with the carb hanging over the RR tire and large diameter filters are rubbing the tire. Flat siding the filter took care of that. The problem then is that it is more costly to make a filter that is not completely round, so you end up with really expensive air filters that are slightly better flowing than the cheap-os.
Now, as for the material used in pleated filters...K&N & Walker both use cotton Remay (to my knowledge.) The inexpensive knock-off filters that most kart shops sell are made by S&B and the pleats are made of paper. Again, out of the box, they all flow similarly - but after a few washings and oiling, the cheap paper filters break down and start to restrict air flow significantly. The K&N and Walker continue to flow nearly as well as a brand new filter. The old adage, "You get what you pay for" is certainly true in this case.
Pre-filters: The Outerwears restrict airflow less than foam that is oiled. Almost all of the dirt that I see getting past the Outerwears is past the elastic at the base of the filter. Foam without oil is worthless. It's the oil that catches the dust (same with the pleated filters.)
Also be sure to use the correct oil for pleated vs foam filters.
-----
Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
33 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
The power difference is often in the flange and the transition area where the rubber mold meets the pleated filter.
If you compare a standard 3 1/2" X 4" filter from one brand to the next (new) there will be very little difference to one that is 3 1/2" X 6" or 8." All of the air flow comes in at or below 2" from the flange. Simple test that we did at a trade show years ago when super tall filters were all the rage for flatheads...I think it was Frank Bondatti who was there selling tall filters as fast as he could take the money and hand racers their new filters. Not a knock on Bondatti, I'm sure he was told those filters were better. We had Tom from Superflow in our booth with our new SF60 so we bought one of the tall filters and started testing right there at the show. Take one of those tall filters and draw a ziplok bag down around it. The airflow doesn't change one bit until you get within 2" of the base of the filter.
So the next thought is to increase diameter and leave the height short. Ok, but there's a limit to how much that helps as well. Now comes the animal and clone with the carb hanging over the RR tire and large diameter filters are rubbing the tire. Flat siding the filter took care of that. The problem then is that it is more costly to make a filter that is not completely round, so you end up with really expensive air filters that are slightly better flowing than the cheap-os.
Now, as for the material used in pleated filters...K&N & Walker both use cotton Remay (to my knowledge.) The inexpensive knock-off filters that most kart shops sell are made by S&B and the pleats are made of paper. Again, out of the box, they all flow similarly - but after a few washings and oiling, the cheap paper filters break down and start to restrict air flow significantly. The K&N and Walker continue to flow nearly as well as a brand new filter. The old adage, "You get what you pay for" is certainly true in this case.
Pre-filters: The Outerwears restrict airflow less than foam that is oiled. Almost all of the dirt that I see getting past the Outerwears is past the elastic at the base of the filter. Foam without oil is worthless. It's the oil that catches the dust (same with the pleated filters.)
Also be sure to use the correct oil for pleated vs foam filters.
-----
Thanks and God bless,Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
33 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com