How to Install Dual K&N Air Filters
By Rob Robinette
This is a cheap way to replace the stock air box. You'll need two
large $26 K&N filters that fit a 2 1/2 inch pipe. They sell two sizes of air
filters with a 2 1/2 inch flange, I got the longer of the two (sorry, I don't
have part numbers but they will understand what you want). If you're still using your air pump
you will need two small (about 2 inch) K&N filters with a 1 inch input flange.
The size of the filter doesn't really matter, just the mounting flange. Summit Racing sells
all of these filters.
The charge relief valve and blow-off valve don't need filters, they only dump
air (outward flow).
You will need two 2 1/2 inch food cans to
connect the stock rubber air pipes to the filters. Old El Paso Enchilada sauce cans are a
perfect fit. You'll also need two 2 1/2 inch hose clamps. The cans won't be
visible, one end is in the filter and the other is in the intake hose.
2 1/2 inch K&N air filters with
ASP pipes and aluminum heat shield
Remove your air box by taking off the lid, removing the filter and
take out the bolts in the bottom of the air box. Remove all six hoses going to the air box
and pull it out. You can get rid of the hoses that run from the two blow-off valves to the
air box. They can discharge their air into the engine bay without filters (no air flows
into the valves). If you are using your air pump put the two small K&N filters in the
air pump hoses. If you aren't using your air pump you can plug the two pipes with 3/4 to 1
inch rubber plugs available at auto parts stores (that's what I did, my air pump is still
in the engine bay but not spinning).
Use a can opener and remove both ends of the 2 1/2 inch food cans.
Clean them really well and paint them flat black to make them look acceptable (they'll be
covered with the hose and clamps anyway). Slide the cans into the stock air intake lines
and secure them with hose clamps. Slide the K&N filters over the food cans and tighten
the hose clamp that came with the K&N filter.
I fabricated an aluminum heat shield to direct air from the right
side of the radiator to the filters and keep most of the hot air out. I
fabricated a pattern using cardboard to create the shield. Once I got the
cardboard to fit just right I used it to mark the pattern on a sheet of aluminum
I got from the local Ace Hardware store for $6. I used standard tin-snips to cut
the aluminum. The shield bolted in place at the intercooler and engine bay
I have ASP intake
pipes (no longer sold) so I didn't need the food cans but I've been told they work great with the stock air