Here's the info I received from Kuryakyn this morning. Kind of lengthy but VERY good information. Sounds like the ProR may be more than you really need for your Fatboy..unless you plan on really building it big time. Anyway..digest the information and then devide whether you think Kuryakyn is a legitimate piece of gear.....I think it is.
Jim has asked me to explain the flow on our air cleaners. I do not
actually like to give out flow data on our air cleaners for reasons I
will now tell you. I instead like to use the horsepower potential of
the air cleaners, as this is a much more important figure to know.
I have done extensive scientific testing on the air cleaners with
both the proper type fixture with an expansion area built into it and at
high pressure differentials as compared to a lot of the testing I have
seen. We also did a considerable amount of dyno testing. Because there
is no standard for AC testing, the numbers we have mean nothing when you
try to use the data to compare to anyone else's data. It creates a big
problem with the public not understanding that most of the CFM figures
for air cleaners out there were all done with different testing
procedures at different test pressures. I ran into this first hand on a
discussion board I am on. There was a thread on how much do different
air cleaners flow and how much flow do you need for a certain cubic inch
engine. It turned into a fiasco where nobody could agree with each other
on anything. People were throwing out all kinds of flow numbers and
formulas for figuring how much flow or area you need in the element. It
went on forever and I think people knew less when they were done than
when they started. This is why I won't go there and get rapped around
that axle. There is no winning in the flow number game. For this reason
this data is for our own knowledge and we do not publish it. I prefer to
tell you what we have found to be the upper horsepower potentials for
each of our air cleaners. This is what is really important to the end
user. All of our AC's flow a great deal more air than a stock AC, and
will enhance a stock bikes performance, but the difference really comes
out when you start having higher HP engine builds.
Just so you know, the Hypercharger is not meant to force high
pressure air into the intake tract. They are vented on the bottom to
prevent this because it can cause carburetion problems. A lot of people
do not understand this either.
The original Hypercharger is good to about 90 HP before it starts to
cost you a percentage of your HP. An example is our 95 Wide Glide with a
Wild Things hop-up makes 120 HP with our High Five AC installed. With
the original Hypercharger installed it makes about 106HP. Even though
the bike made 106 HP with the Hypercharger, it lost power, so we do not
say it is a 106 HP AC. We did the same type of testing on a 130 HP
engine. The stock Hyper made 114 on this bike. With the Stinger upgrade
the bike again made 130 HP. We call this new upgrade the Stinger. It
adds an end element and more opening to the Hyper. This makes the
Hypercharger able to support up to the tested 130 HP on the previous
mentioned test. It may go beyond that, but that is the highest we have
tested it at so far. On a 90 HP engine, the original Hypercharger will
allow you to make 90 HP, so this is what we rate it at.
The original Twin Velocity is good to about 100 HP. The new Twin
Velocity PLUS flows enough air for around 120 HP.
The Pro Hypercharger is good for 110 HP.
The new Pro "R" Hypercharger is a new advanced design and flows an
extreme amount of air. We have not found the upper limits of this air
cleaner yet. The highest power bike we have had to test on in the shop
was over 140/140 for HP and TQ. I estimate this air cleaner to be able
to feed an engine in the 150's for HP. Maybe higher.
The new High Five is in the same league as the Pro "R". It will
supply enough air for just about any street build you can come up with.
The new Skull AC is very close behind these two AC's in performance
Both the High Five and the Pro "R" are some of the highest flowing
AC's I have tested, and I have tested most all of the popular high flow
aftermarket AC's. Part of this not only has to do with the end breathing
element technology but also in the design of the backing plate. It has
an insert that goes over the bolts after you install it. There are then
no stand-offs or bolts to cause turbulence at the entry. The backing
plate leads the air from a flat surface 90 degrees to the throat to a
parabolic curve radius into the throat of the carb or throttle body.
This is the best shape you can have for the entry to an orifice.
To give you a comparison, the Screaming Eagle AC is good up to about
105 HP before it starts costing a percentage of your power.
One of the things that has given the Hypercharger a bad rap is the
fact that people do not clean the elements because they are a little
more work to get at than most AC's. They run the Hyper for years and
thousands of miles with no cleaning. They then put their bikes on a dyno
at some event and their power is way down. They blame it on the Hyper. I
had a well known mobile dyno operator tell me this same story. Another
thing that happens is people will discount the Hyper's ability to work
because of it's unique design. They think it is a gimmick and judge it
without a fair trial.
I know I gave you a little more information than you probably
needed, but I thought you might find it interesting. What it means to
your FXDWG is, the original Hypercharger flows more than enough air for
your 88" bike to make as much power as it is able to. On a stock bike no
other AC will add more power no matter what anybody says. Even our ultra
high flowing High Five or Pro "R" will not add any more power because
the Hypercharger has not reached it's flow limits at anything under 90
I have attached a couple of dyno charts to show you what our AC and
a pipe can do for a stock bike. As you can see, stock bikes vary in
output. If you go to the web sight linked below you can look at a lot of
high output combinations all using our AC's.
I hope this information helps you.
Michael Jay Roland
Performance Division Manager