It's not "dyno loading specific", it's not "apparent only on a dyno hp", it's not "only there under inertia loading" - It's real power, measured against a real, lifelike, "load" - as the bike experiences in the real world -

At least 10% of the dyno buying facilities in the USA have decided to go with honesty and real HP - using the EC997 Dyne systems as used at the best of tuning centers -
The Factory Pro Tuning Centers

You'll see them in F-USA - you'll see them as the winners of the biggest classes in WERA National Championships, you'll see them as multiple World Suzuki Cup Champions, you'll see them as the 2004 National USA Endurance Champions, too - They don't get fooled - they all use Factory Pro EC997 dyne systems for True HP.

Anyway.... the stacks.......
OK - the above dyno chart shows the power difference between a bike with stock exhaust and stock air filter, tuned to make best power with the TEKA SFI Programmer (not pc3) and we changed just the stacks and just retrimmed the fuel with the TEKA in 3 minutes.
You can see on the 2 lower red and blue CO% lines that we didn't change the mixture very much.

The original stock Suzuki "short" stacks have the same problem as the Graves stacks on the fi R6's - there's simply restricted airflow at high rpms to make optimal power at very high rpms - insufficient radius / flare. Interestingly, I think that they would only work well on a flow bench if you didn't duplicate the actual intake velocity and used lower than an engine flow rate, typical flowbench velocities -

The results are typical for our patented v stacks - The Factory Pro stacks are shaped  better than stock, so they propagate and recover the intake wave more efficiently, as shown by the "meatier" upper midrange and make more power at redline, due to the improved flow rates at higher velocities.

Actually, as it turns out, the "short" stock Suzuki stacks, after the radius problems were worked out, were "too short"!
They use a shorter stack to bias the high rpm power, with poor wave rates - We used better wave rates and then we could lengthen the intake tract length to get more midrange power. We ended up with better top (flow related) and better upper mid (wave rate).

The eternal battle in V stack development (notice I didn't say "design"!) is that what works best "on" a flow bench is NOT what works optimally "on" an engine - and what "perfect" intake tract length "calculates" as best.... is only "best" by accidental coincidence.

There has only been one manufacturer and then, on only one of their models, (as of April,05, we've done ~20 successful v stack R&D projects) that has had a set of stock stacks that simply worked as well as they possible could - Congratulations!

But I digress........ Buy these stacks - It takes about 1/2 hour to install and it's easy to do.
They work a lot better than stock and you don't have to modify your airbox to get that 2 to 5 True HP. It's as much power gain as some exhaust systems deliver.

As always,  with stacks......
If you've tweaked cam timing more than 3-4 degrees, ported the head and otherwise mucked around with the intake tract resonance, the optimum stack length will probably be different than the standard 45mm outside / 60mm inside spec.
These "std" stack lengths are for a stockish engine with a pipe (or not), an advancer, a TEKA4usb, a PC3, a TEKA SFI tune, a filter and a TEKA Fire or TRE.

 Hmmm..... that might be legal for racing (but NOT AMA Supersport).... You "could" call them "air jets", couldn't you?
:-) 
Marc Salvisberg -
The Industry's Evil Curmudgeon