I'd love to have access to a wind tunnel, however, I don't. Tests have occurred over a 5 year period in our modest test range at NAP.

The first tests were designed simply to show us the number of rotations that occur over 20 yards. The process was simple. We marked 1 yard increments with tape on the floor. We then placed a shooting machine at each mark down the range and shot a group of arrows with a specific vane/feather configuration.
The cock vane position resulting at the target was recorded on a data sheet. The data sheets actually had 1 inch circles marked off like the face of a clock so the visual position was easily marked. An average for the group was taken and standard deviations were calculated.

The neat thing about this type of test is that we could very quickly see the comparisons from vane type to vane type.

Another cool thing we could do is incorporate a chronograph set up at the target for each recording distance. Knowing the speed at the target from each distance also allow us to calculate RPM's and determine speed decay.

We then determined with a rather detailed and complex series of tests that to stabilize a broadhead at about 260 FPS the arrow needs to turn about 1 rotation over 3 yards.

Our previously recorded data was then able to provide even more information, and in this case, very useable information. We looked at each data set and found the range at which each fletching type produced 1 full turn.

A standard 4 inch vane (AAE, Duravane, Bohning, Etc.) with a 1/16th inch offset
reaches 1 full rotation between 12 to 15 yards.

A 5 inch helical feather with a 3 to 4 degree wrap reaches 1 full rotation in between 4 and 7 yards.

A QuikSpin 4 inch perfectly straight reaches 1 full rotation between 4 and 7 yards.

A QuikSpin 4 inch with a 1/16th inch offset reaches 1 full rotation between 1 and 4 yards.

So in answer to Black Frog's question, the QuikSpins accelerate at the same rate when perfectly straight on the shaft as a helical feather and at a faster rate when offset on the shaft.

This data helped explain why historically, feathers are consistently better fletchings in stabilizing broadheads. The data also gave us a hint of how well the QuikSpin vanes could perform with broadheads.

As a side note for anyone interested, degrees of offset are measured as follows:

Inverse Tangent of the offset distance (in inches)/the length of the vane in inches. An example follows

1/16 = 0.0625
Inv Tan of 0.0625 = 3.5763
3.5763/4inches = 0.894 degrees or approximately 1 degree.

We can then demonstrate that a 2 inch vane at the same 1/16th offset
3.5763/2 = 1.788 or approximately 2 degrees.

I am providing this information mainly because most people do not know how to measure offset and there is much myth surrounding it in the industry.

Most of the data was compiled in a 20 yard range. The RPM information was compared linearly at 10 and 20 yards. The 3000 RPM measurement occurs at 20 yards. We find that the increase in rate of the rotational vector is greatest as the arrow leaves the bow. Once the arrow begins to rotate 5 turns in 3 yards, the rotational acceleration slows down. However the spin rate remains very high.

I do not yet know when the rotational rate begins to decelerate.

Wait until the target guys get a hold of this!