Installing a Fender Well Intake Cold Air Induction System

Drew originally had a Thrasher CAI kit in his Impala, but felt there was room for improvement.  This is his Fender Well Intake (FWI) system.

I dismantled my Thrasher Cold Air box and used the 9" cone to make a Fenderwell Intake (FWI).  These are supposed to be the best intake possible for cold air with the exception of removing the hood!  I used 3"-3" rubber coupler on the throttle body, to 3" inner diameter PVC pipe, into my fenderwell, then to my 9" cone filter.  I drilled a hole in the rubber coupler and stuck my AIT sensor in there.  The rubber coupler acts like an Fduct and the hole as a grommet.  I like it... cold air ALL the time.  You know when you first start up your car, the air is cold and you have lots of power?  In the case of the Thrasher CAI you have the same feeling- cold air when you start up your car or when you are moving (cause the box gets fresh air)?  With this FWI you get that cool fresh air all the time.

This is the parts list for the all PVC version of the fenderwell intake (Home Depot style):
(1) 3" PVC joint connector (for joining cut PVC pipe to street side of 45 degree elbow.)
(1) 3"-3" rubber coupler
(2) 3" PVC 45 degree street elbows and (1) 3" PVC 90 degree
(1) straight piece of 3"PVC pipe about a foot long.(cut to fit application)
(1) 9 or 7" cone filter
(1) bottle of PVC cement(epoxy)

  1. Disconnect battery (you do this so the PCM can learn the added air coming in on reconnection)
  2. Remove all the pre-existing CAI and set the PCM down at the bottom of the engine bay.
  3. For easy installation, jack up car, remove driver's side front wheel, and even the headlight if you like (I didn't)
  4. Remove the black fenderwell wheel lining from the wheel well (it basically screws around the outside and underneath.)
  5. Remove headlight (for fitting purposes and better sight - 2 bolts)
  6. There is a brace on the inside of the fender (really flimsy), at the bottom of that brace there is a bolt (10mm), remove that bolt and push the brace to the inside of the fender. That brace looks like a triangle with a hole in the center.
  7. Drill a hole in the rubber coupler about 1/4-1/2 inch for the AIT sensor. CLEAN out inside of coupler.
  8. Connect the 3"coupler to the TB (throttle body) It will be a tight fit, but will fit.
  9. Put the street side of a 45 degree elbow into the coupler
  10. Connect about a 4 1/2 inch long PVC pipe into the 45 degree elbow
  11. Use the PVC joint connector to connect the PVC pipe to the street of the 45 elbow on the other side
  12. Connect the 90 degree elbow street into the 45.. now you're in the fenderwell.
  13. Connect a short 3" PVC pipe to the 90 degree elbow and that's where you'll connect the cone filter.  It is a tight fit, but the brace acts as support and holds the PVC in place.
  14. After everthing is in place, mark connections with a marker so you can get it back together when it's time to glue.  It should fit snugly, be perpendicular to the ground, and a tight fit, but it will work.
  15. CLEAN out all the pipes before you cement them together and install.  You don't want PVC shavings and rubber sucked up in your engine!!!
  16. After every thing is measured up and you are satisfied, you can now epoxy and tighten all your connections.
  17. Again make sure everything is tightened well, put the wheel well liner back on, headlight and reconnect battery.
  18. Push the IAT sensor into the rubber coupler hole.
  19. I just tie wrapped my PCM to the frame, it holds well.  Put a pad of some sort underneath to cushion the PCM.  If you'd like to (I did) get some insulator wrap and wrap the PVC to insulate from further heating.  That's it, good luck!