procedure to install a cone filter on a 96+ 993 is slightly different from
a 95 993. If you have a 96+ 993, there is the extra temperature sensor
on the intake to deal with and also the way the air box is mounted to the
intake is different. And once you removed the air box on a 96+ 993
it is much harder to install it back compare to the 95 model 993s.
(1). Pull off the snorkel that goes to the air box.
(2). Remove the 10 mm bolt that hold the air box to the engine. Grab the air box and lift it up from the front of the air box and slide it to the right (passenger) side to reveal a rubber ventilation hose that is hooked to the left inside of the air box. Loosen the clamp and pull the hose away from the air box.
(3). Reach in to gain access to the two strap that strap the air box to the throttle body, and unstrap them. The air box can now be removed.
This step is optional. The factory intake have these square cube
mesh screen on both sides of the intake. Most people have them removed
to allow more air flow to the engine. (Not sure if it will make any difference)
Pop the metal ring inside of it to get the square mesh out.
(5). In order for the cone filter to fit nice and snug I removed the rubber intake tube on the intake to gain a better access in mounting the cone filter. To remove the rubber intake hose you will need to loosen the metal strap and the wiring harness.
(6). The small filter that comes with the kit also needs to be installed on the breather tube that is now exposed after it is disconnected from the factory air box. To mount the small filter on the breather tube I had to disconnect the breath tube at the starting point and mount the small filter on it while the tube is off the car in order to have a tight fit.
(7). Install the supplied snorkel tube into the factory snorkel and mount the other end to the cone filter.
This cone filter kit was purchased from MSDS for around $150, the cone filter sound on a 95 993 without the varioram is very different than from a 96 993 with the varioram. For one thing you can clearly hear the growling sound of the intake even if the RPM gets to about 5000 RPM, but on the 96 993 with the cone filter once the varioram opens up all you hear is a droning sound that drones out the growl of the cone filter.