SCORE Journal - The Official Publication of SCORE Off-Road Racing
Issue link: http://read.uberflip.com/i/501768
of lightweight aluminum. And the filter itself is made of a heavy duty paper element." The critical take away information is to know it is entirely possible to compete in a grueling desert race without changing air filters if the intake system is airtight, and you have the right air filter for the engine. "You have to start at the air filter, and having the correct sized unit for the demands of the engine. Not having the proper sized filter will already put you at a disadvantage, causing a dramatic increase in restriction, especially as the filter becomes loaded with dirt during the long race," said Colin Greenlees, sales manager for R2C Performance. "As the filter becomes clogged, air struggles to get thru. This causes the engine to bog down and not run at its peak level. So taking the time to figure out the correct size filter and match the demands of the engine is crucial in a long off-road race." While engine size and its position in front or at the rear of a race vehicle isn't a determining factor, air intake experts agree that it's most important to find out where the cleanest air will be available around the vehicle. "You want to start with the cleanest and coolest air before you even get to the filter. The key to that, of course, is where is the air flow to the engine starts from," says Greenlees. "You don't want it pointing straight at your tires or sucking in hot radiator air." " It is possible for a filter to last an entire race," says Johnny Jump, K&N Engineering Powersports Brand Manager. K&N air filters have finished many races without being replaced, but it comes down to many factors such as, what position you are in, (following or leading), how the filter is placed within the vehicle, not being over- oiled, how long the race is, etc. On the big trucks, truggies, and Class 1 cars there is plenty of room to run two filters, which provides even more filtering capacity." Some teams believe that if they can gather a bigger "gulp" of air would be a great place to start. But air intake experts say that's not always a great idea. "In our opinion a bigger air scoop just gathers more dust." Cappos said. "We tell our customers to face a scoop backwards if one is used. The theory of ram-air in off-road racing is never really achieved, as the speeds are just not high enough. Besides, you won't even get to top speed if your filter is plugged with dust." Cappos gives an example of this in a typical race engine. "Just for reference, a 6.2L GM LS race engine at 6500 RPM is flowing about 640 CFM. ON ATV VEHICLES, K&N USES ITS POWERLID TO PROVIDE A SEALED AIR CHAMBER FOR THE FILTER, BUT WITHOUT RESTRICTING THE AMOUNT OF AIR AROUND IT. POST RACE LOOK AT A THROTTLE BODY. UMP ESTIMATES FIVE TO EIGHT PERCENT OF DUST AND SILT CAN GET INTO THE ENGINE WHILE RUNNING IN CONDITIONS SUCH AS DEEP SILT BEDS. 040 SCORE JOURNAL