billet velocity stacks add 5hp at 7000 rpm?

[lather]

I stumbled across this site looking for stuff for my Ninja 500R. The dyno chart and 5 hp claim are for a ZX14 but it seems they are marketing them for ZG14 also. They are more $ than I am probably willing to spend on an 08 with 100,000 miles but 5hp at 7000 rpm would be tempting.

http://www.factorypro.com/

The website is not great for navigating, click continue to online sales, then scroll down to ZG14

[B.D.F.]

Questionable IMO. Certainly velocity stacks can only be tuned for one specific RPM though so even when they do work it is only across a very narrow engine speed; if those peak at 7,000 RPM the effect would be lost, and might actually be worse than no stacks at all buy engine redline.

The bike already has a mild but noticeable supercharging effect with the air intakes facing forward in the cowling. It is not engine  speed dependent but vehicle speed driven.

Besides all of that, you would probably gain a lot of intake noise using velocity stacks. Just removing the 'flies makes the engine quite a bit louder in my experience (I was amazed at the difference for the first ride after removing the secondary 'flies).

Brian

I stumbled across this site looking for stuff for my Ninja 500R. The dyno chart and 5 hp claim are for a ZX14 but it seems they are marketing them for ZG14 also. They are more $ than I am probably willing to spend on an 08 with 100,000 miles but 5hp at 7000 rpm would be tempting.

http://www.factorypro.com/

The website is not great for navigating, click continue to online sales, then scroll down to ZG14

[lather]

Yes, questionable IMO too,  even for a ZX, hence the ? in my title. Even more questionable is marketing the same part for the ZG which IIRC has larger TB bores and different cam.
Here is their full HP claim:
+4 hp at 4000
+3 at 5000
+3 at 6000
+5 at 7000
+5 at 8000
+3 at 9000
+2 at 10,000
and they include a dyno chart labeled "TRUE HP"

[Son of Pappy]

I've been looking at doing this for some time, my issue is getting enough air to them.  My peak HP number plateau was long which to me indicates I need more air.  It could mean fuel, but I doubt that is the issue.