We are asked regularly why we do not sell a "Pod Filter" air intake kit since it would be simple to assemble one. Here is what our testing and
opinion on this type of setup is.
stock dual carbs are Constant Velocity (or "CV") carbs which are designed to work together as a unit using the "black air box". This gives the bike the advantage of two individual smaller
carbs at lower RPMs (creating more torque), but also gives them the added advantage of working like much bigger carbs at higher RPMs (creating more horsepower). It's not unlike the
way a two into one exhaust system works. The two carbs scavenge vacuum off of each other.
By installing a pod setup, you essentially split the carbs and force them to work independently by removing the "black air box". The black box actually stores vacuum
created between the carbs. This vacuum causes the slides in the stock CV carburetors to lift quicker. It also draws fuel through the main jets faster, hitting the tip of the needle harder
which atomizes the fuel much better, creating a much better air fuel mixture for combustion.
When you install a pod filter system, you loose that suction function (that sounds like a "Schoolhouse Rock" song). This is why
pod systems require you to go from a 112 main jet all the way to an absurd 150 or even larger main jet. Think of it like sucking your favorite beverage through a straw, as opposed to
just letting it flow through the straw on its own. To get the same fuel flow without the suction, the pod system needs a much bigger hole to go through.
The performance gains that are "felt" with a pod filter system is actually deceiving. Yes you do gain some horsepower at the
very top end once the engine RPMs finally creates enough vacuum on each separate individual carb, but you loose performance at the low / mid RPM range (where a cruiser is designed to run).
So when the RPMs finally get high enough, it "feels" like a rush of power and that is what is deceiving. But by then, unfortunately it's time to shift gears and you'll move back to the
lower RPMs again. What is actually happening is a loss in bottom end power, with a rush at the top end. Like I said, its deceiving.
All of our testing has shown power develops much faster with a traditional
air intake system utilizing the "black air box".
So from a stop light what you would experience is this; the bike with a traditional air intake setup will accelerate quicker off
the line and into the mid range. Then once the RPMs get high enough, the bike with the pod system will start to catch up. Problem is, by the time that happens, it's time to shift and it
all starts over again.
Pod systems have had great advertising, but if there was an advantage in them, we would simply make one ourselves. We
have decided to not take advantage of that hype.
Another thing is, we are often asked, "I've installed a pod
air kit, which cam should I install to get some more bottom end performance?" Well, converting the CV carbs into a pod setup, makes that a proverbial game of "whack a mole". The
solution isn't a different cam, it's a better air intake setup, then the cam will be able to realize its performance purpose.
We hope that helps with any questions you may have.