topless air filter
Road Master
Joined: Feb 2007
Posts: 1,161
Likes: 39
From: LOST WAGES
That's why every Porsche race car has the factory airboxes installed.
NOT
(1) The Stock Map is for Emissions required Standards, not fuel economy
(2) The stock snorkel is not force fed by high pressure (snorkel is directly behind the frame neck and not out in the open)
(3) The reason for the two different length velocity stacks is to match the exhaust (which has two different lengths)
(4) The reason for the air filter top and snorkel is for EPA Noise Requirement nothing more nothing less
NOT
(1) The Stock Map is for Emissions required Standards, not fuel economy
(2) The stock snorkel is not force fed by high pressure (snorkel is directly behind the frame neck and not out in the open)
(3) The reason for the two different length velocity stacks is to match the exhaust (which has two different lengths)
(4) The reason for the air filter top and snorkel is for EPA Noise Requirement nothing more nothing less
Last edited by Hal64hd; Aug 25, 2014 at 03:52 PM.
You're right... and someone else said that too... made no sense to me till I found the instructions and read them. The H-D PRO STAGE II MOD that calls for removing the inner top airbox cover and drilling holes in the bottom section of the airbox. You got to look at that action along with the cam changes. It is the cam changes make the removal of the airbox make sense in this case. When the cam changes change the valve timing the original tuned airbox design benefits are negated -- in fact the airbox becomes a liability then. http://www.harley-davidson.com/en_US...ts/-J04779.pdf
Stage I
Joined: Feb 2017
Posts: 1
Likes: 0
From: Brooklyn
Although you make some extremely great points .. I hate to break it to you.. that horn you say is in a high pressure zone.. yeah.. it's not.. not on the V-Rod Muscle at least ..
The Horn or trumpet as you call it has had its place on airboxes both two wheeled and four shelled vehicles since tunning began..
I'm no expert but since the end user started tuning the first thing to go has ALWAYS been the the airbox... it's common knowledge that more air equates to more bang.. the aftermarket development industry has proven that restrictive air boxes diminishes power ..
Like I said, great great points but that little little fact of the location on the actual bike throws your theory out the window...
Yes!!! - you can funnel in air to act like a super charger but in this case I'm going to go out on a limb and say your wrong..
The Horn or trumpet as you call it has had its place on airboxes both two wheeled and four shelled vehicles since tunning began..
I'm no expert but since the end user started tuning the first thing to go has ALWAYS been the the airbox... it's common knowledge that more air equates to more bang.. the aftermarket development industry has proven that restrictive air boxes diminishes power ..
Like I said, great great points but that little little fact of the location on the actual bike throws your theory out the window...
Yes!!! - you can funnel in air to act like a super charger but in this case I'm going to go out on a limb and say your wrong..
I was tryint to do you a favor -- to point out that Porche is one of the few manufactures that know the trick to creating a tuned intake tract. The "fer sure" indicator that this is a tuned intake tract on the VRod is the long trumpet inlet, the air-tight sealed air box (rubber gasket and clamps all the way around), and the variable height velocity stacks that aren't interchangable (you can't change their positions front to back -- they are keyed uniquely).
The principle which make it work are the same principles used by header- exhaust manufactures to use an exhaust pulse in a lenght-tuned system to "pull on" the following exhaust pulse -- to scavange the exaust out of the cylinder as soon as the exahaust valve begins to open. The tuned intake track works the same way except in reverse.
In lengthen that path to correct the timing of the pulse.
Tuned exhaust and intake tracts have a specific rpm range that they operate opimumly.
Dynometers are over-blown as far as value. They may allow you to get an initial tune but only real-world on-the-road trials will allow you to develop a tune that is optimal.
Another reason you don't show an increase of HP/torque with the airbox installed is because the entended end of the trumpet gets air from a high-pressure zone that forms when the motocycle is moving through the air-stream. You can't duplicate that with a dynometer.]
The principle which make it work are the same principles used by header- exhaust manufactures to use an exhaust pulse in a lenght-tuned system to "pull on" the following exhaust pulse -- to scavange the exaust out of the cylinder as soon as the exahaust valve begins to open. The tuned intake track works the same way except in reverse.
In lengthen that path to correct the timing of the pulse.
Tuned exhaust and intake tracts have a specific rpm range that they operate opimumly.
Dynometers are over-blown as far as value. They may allow you to get an initial tune but only real-world on-the-road trials will allow you to develop a tune that is optimal.
Another reason you don't show an increase of HP/torque with the airbox installed is because the entended end of the trumpet gets air from a high-pressure zone that forms when the motocycle is moving through the air-stream. You can't duplicate that with a dynometer.]
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