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post #7 of (permalink) Old Dec 18th, 2012, 6:04 am
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Join Date: Jan 2005
Location: Newbuying, Flatoutcounty, Sweden
Posts: 5,736
Regarding post #1.

All of this tells us why Ducati places the superbike air filters in the air runners. This location avoids lowering the frequency of the airbox (by not filling up a large portion of the airbox volume with a bulky foam filter) and prevents disturbing the airflow near the velocity stacks as well as improving throttle response by maintaining a large free air volume between the filter location and the velocity stacks.
I beg to differ, reason being real world tests (by myself) which proves these assumptions not valid.

Imo the negative power results from over the stack filters are from the filter collapsing on the stacks.
Now, with a cage inside that filter holding it up there is no loss at all at any part of the rpm range.

So that means:
-The resonance is not disturbed by filter material inside the box
-Flow is not disturbed by a filter in that position
-There is enough air readily available
-Fuel mixture is unaffected

What I did for testing was dyno and map each:
-Without any filter
-Overthestack cage-inside-type filter (MWR)
-Overthestack NO cage filter

Without filter and MWR were identical powerwise from start to end, not a single hp difference anywhere and identical AFR.
Overthestack NO cage filter lost 7hp(remapped to fit) to the other two.

After this test Ive done the No filter/MWR test a couple of more times with the same result.
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