Page 18 - KCRPCA July

TECH ARTICLE
More air in, more air out = MORE HORSEPOWER
18
Jul / Aug 2017
Karl Wilen
simple, or at least what I will call easy or bolt on horsepower. Beyond that, we are talking engine internal work, which isn’t in the realm of reality for most people, so we are going to skip over that. More air in, more air out = more horsepower.
How do we do that in a car typically? Intake systems and exhaust systems are the obvious answer; right? Couple that with an ECU tune? Most Porsche vehicles nowadays are coming with 4 catalytic converters, 2 on each side of the engine. You can typically remove the rear most cats with an aftermarket exhaust system and the car is still happy, i.e. no check engine lights. Scratch that, you never heard me say “remove catalytic converters”; that is all theoretical information.
What to do about the intake? We need to get more air into the engine. Each model presents its own little differences, but this can be done as simply replacing the stock air lter with an aftermarket air lter like a BMC brand which is used in the Porsche cup cars. I try and stay away from K&N lters as the oil on them contaminates the mass air ow sensors in the engine and will cause check engine
actually pretty good with an aftermarket lter, so if you decide to replace it with an aftermarket air box and cone lter, then you need to heavily insulate the replacement box from the engine heat or it will create a hot air intake which does no good because we need cold, dense air to make power. So now that we have the intake air ow increased, we are done; right? Well....not exactly. As the air comes through the air lter, it travels through the air intake tube to the intake manifold where it splits into a T plenum. Air is then directed to each side of the engine equally in theory. The problem is that the stock intake plenum diverter is incredibly poor and creates a pressure drop at the plenum. The answer is the IPD intake plenum. This replacement plenum is designed more like a Y which channels the air through more ef ciently while reducing air turbulence and increases the velocity of the air going into the intake. Imagine coming to a T intersection in your car. Going through that intersection requires you to slow way down as you negotiate the corner, whether it be left or right. Then imagine coming to a Y intersection, where you can pretty much take either direction at a much higher cornering speed. This is simple and effective. The IPD plenum, is in my opinion, is one of the best bolt on upgrades you can do to a 996/986
Bolt on the
HIORSEPOWER
get asked all the time about what lights....plus those sensors are expensive can someone do to increase the little buggers to replace! Some cars, like performance of their water-cooled the 986 Boxsters, have aftermarket intake
Porsche. The key to horsepower is pretty boxes available. The stock airbox is