I noticed these babies on the fat300 web site.
Does anyone have them installed? If so, can you recommend the expense for the claimed 2-6 hp increase?

It's like Brock said; Look at our screen door. It's just as heavy and as tall as your original door. Ours though, has a puppy door little sparky has to crawl under cause and effect we cut the door down a few mm. So you get a draft underneath and every other pet in the neighborhood walking under the door is stacked against you.

We can't tell if you get 2 or 6 hp so we are just going to guess at it??? Since that's a huge jump from even finding 1 hp out of the bike but no, we found 6 big ones for you just buy these, go head, make my day... "Reach Around."

No, I said that. Brock said it makes no hp, just moves the torque band around. It's like saying I have this door that swings a full 90° each and every stroke. I can open the door fast or slow. I moved the same 90° of door swing via 2 moves. Either one moves faster is the event or one takes time and slows the event. The event is the full swing of the door is the same stroke of the engine, but how fast did you make it move in time climbing over that stack and then down into the engine?

Like I climb stairs to a 10 story building or a 3 story building. It takes time for the elevator/you walking up the elevation takes time. Did you still open the door the full monty? Yes. Did it happen quicker? Yes. Did it make more hp? well for argument sake, yes. I brought the same hp band that was upstairs and brought it downstairs a little quicker out the door am I.

Kind of see how that works? Key phrase is 'speed event" was the change in mm stack?

"was upstairs and brought it downstairs a little quicker out the door am I"...okay..in real time(noticed performance),what does this translate to?Considering no changes to ignition or any of that.What if the ignition is advanced already?You're 'moving' the 'event' 'ahead'(faster) of a stock configuration(stacks)...and this will produce what?(in felt performance)

I guess what I'm asking is do you feel that added HP from take off and on up with roll-ons and such?

* Last updated by: Grn14 on 6/3/2013 @ 12:48 PM *

Yes. Everything remains at a constant. Meaning, even if the speed increase, it still sucked on the IAP and this sets the timing too. So load based being what it is, she can rev in a instant if you grabbed a handful at idle, right? It's as fast as you can make it happen. See how the engine is responsive to a snap of the throttle at idle?

If you remove the air cleaner = Restriction removed ~ Happens faster
If you remove the muffler = Restriction removed ~ Happens faster
If you remove the stacks = The air is open to that opening, not going up and over the intake stack is the instant of a move times how fast can you bring the next fire sequence off?

How fast can you suck the air in? How fast can you expel it to repeat the process over and over? If we slowmo'd 2 bikes at TDC compression and counted each rpm, the less restricted would turn more rpm's having that faster event occur sooner. That bike would be down the 1/4 mile faster/sooner.

OKay...thanks Hub.

Thanks Guys.
I get the impression that the expense isn't justified for the minute, if any hp gain.
Your analogies were most insightful!
Thanks again.

I am interested in this mod as well. If it works, $300 is a good investment for 3 hp or more...but even a Race filter supposedly gets you 2 hp for only $80.

I've been hearing about them for 5 years now but not many people get them...so I'm a little skeptical.

Hey Jordan1963 agreed the expen$e just to go that extra hp isn't justified especaily if you live in the NE .
You Can blast as often as you want but unless your on a track or doing drag strip I'd rather save the monies for
unexpected speeding tickets!!!!

* Last updated by: SilvDragon on 6/11/2013 @ 8:46 AM *

Guys... There is no extra HP. V Stacks just move the power. You can get more mid at the expense of your top end and vice versa.

and vice versa.

..so if you get more peak hp and less midrange...that is increased hp. ...I still would need to see people showing improved quarter mile time or at least stronger dyno results.

V-Stack Theory:

I weigh 230 is for argument sake pick a number.
I will now take my beer gut and match the lime drink lady and place that 30 pounds down around my ass.
I weigh 230 is for argument sake is guess my weight in velocity stacks?

Air Fulcrum Theory:

Lay Lady Lime Drink down on the ground all prone.
Place hands behind head and get ready to lift her.
Lay the limes on her ass is now lift her up. Easy right?
Lay the limes on her chest and more fat around her back is check that measurement.
Lift lady limes with all that weight and did you just move her head to chin her chest?
Lift lady torque is all about that weight distribution in HP movement, you go looking at Lady Lime that way?

..so if you get more peak hp and less midrange...that is increased hp. ...I still would need to see people showing improved quarter mile time or at least stronger dyno results.

That is increased top HP. To me extra means= more no? People advertise them like a full system which "create" extra hp. Do you rather have a bike that has 130 hp at 6000RPM and 180 hp at 11k RPM or one that has 124 in the mid and 186 hp at 11k RPM? Also which one is the fastest? What's the point of having a bike doing 200 MPH if it takes 3 miles? Or one that accelerate hard to run out of steam at 10k? If you're going to a top speed event and you have a long road, I can see why you'd want to rob the mid range for more top end because that's where you'd spend most of your time in 6th gear but for 1/4 mile and street performances I don't see the use of it. I guess more mid range at the expense of some top end could be fun i.e Wheelies and darkies out of corners but popping the clutch at 7-8 grands is good enough for me and a stock 14 can trace darkies.
If you really want to do it the right way, you could get a reflash and raise your red line 500 RPM (3-4 hp gain) then install the stacks for more mid range but when you factor in the whole thing (reflash=$375, stacks $250, custom map $250) you're already at $875 and if you're racing a guy with a better system and same skills, he'll probably walk you.

A lot of reputable tuners tried them back to back and dyno results aren't in favor. I was about to get some but was told to save my money. You could look at dogo's dyno numbers if you can find them (might be in a thread about reflash). I believe he had the mid stacks and pulled 180+HP in good weather but I don't remember seeing anything extraordinary in the mid range. 06-07 ZX-14 have 5 hp more on top compared to 08-11 so my advice to people is, get some duals for 06-07 and a single for 08-11. I will get a custom tune this fall when it cools down and will be able to verify that but if I can pull 177hp in hot and humid weather, I'm sure 180+ HP is not a pipe dream LOL

*Correction: Actually read an article on Bikeland yesterday about Busa V.S ZX-14 and Brock said that 08-11 produce actually more HP than 06-07 (3-4 HP) but just take longer to break in.

* Last updated by: dragking on 6/15/2013 @ 10:41 AM *

My opinion will always differ on this.

I for one (Like allot of us), had to much bottom and was not using it all,,,,, I couldn't with stock wheel base and gearing. First trip down the sticky pavement at the track taught me that.

So, 4 me I lost Nothing. How do you lose what your Not using ??? How many of you are riding this beast full throttle in the mid range every day ????? And yes you will have top end gains. Ask any LSR guy.

IMO Top End RPM is where we can all use it ,,, No ? Let's face it, Not all of us here have the skill to launch this bike from a dig at 100% throttle to make use of all this bottom end torque(not exactly but you know what I mean). But,,,,, once bike is out of second and is banging all the gears from 10,800 We do. This to me is where these short race stacks shine and could never imagine tall stacks for more of what I couldn't use anyway. I hate to go against the grain here but I loved them for my application. My Ass Dyno could Never Ever feel what little I lost in the bottom. Take it for what it's worth. Just offering another way of looking at it. cheers.

* Last updated by: Romans on 6/15/2013 @ 7:33 AM *

So, 4 me I lost Nothing. How do you lose what your Not using ??? How many of you are riding this beast full throttle in the mid range every day ????? And yes you will have top end gains. Ask any LSR g

....and what are they doing to move hp up? They look shorter. Do they not stick up as high in the airbox? How do they work?

From Schnitz:
Factory Pro Velocity Stacks work primarily by increasing the engine's dynamic compression - kind of like milling the cylinder head or slightly higher compression pistons over a range of desired rpm ranges.

Increasing compression doesn't require big fuel changes. Dynamic compression is different from cranking compression. Dynamic compression is essentially cranking compression + extra air that gets trapped in the combustion chamber as a result of proper intake tract (velocity stack) length, intake cam closing and also the effects of the exhaust systems in a RUNNING engine. Dynamic compression effects are also related to rpm ranges - as intake ram charging; commonly occurs strongest over a 3000 to 3500 rpm range. (usually....)

Can you get less dynamic compression than cranking compression under running conditions? Yes. If the resonant frequencies of the intake or exhaust systems are wrong, the systems can yank air back out of the combustion chamber before the intake valve closes (and you'd call that a "flat spot").

I'm ready to pop on this one.

Romes, you still selling yours? 25mm or 15mm. How much? PM me if you want.

I'm ready to pop on this one.
Romes, you still selling yours? 25mm or 15mm. How much? PM me if you want.

Rook I'm going to keep mine, although Rob selling his 15 MM Race Stacks. see linkClick

thanks Rome. I'm on it.