I was wondering have anybody had any experience with velocity stacks on ZX-14?

These Are The Short Race Stacks. Loved them. With Gearing = Awesome. Took them out of the Bike when I sold it. They were keepers lol. Installed Turbo on new bike, now these sit on my Work Bench

* Last updated by: Romans on 9/12/2012 @ 3:39 AM *

Romans not even gonna ask you how much would you take
For the stacks but was there any serious improvement
To the bike when you changed em over...I put another
Motor in mine last month and wondered when I was puttin
The stock ones in if anybody was runnin stacks and
What gains would be made ???

was there any serious improvement

The test performed was,,,Wide open in four gears,,, in a place I had marked. Step two removed stock and installed new short race stacks. Repeat test 2 hours later, lifted wheel in third twenty feet early on marker. I,m a fan. With 17/45 gearing it was what I needed. With any gearing moving a bit of power forward is Nice. 10,500rpm tells all.

I'm not sure how exactly the stack size affects power. But if short stacks make more power, why not just put shorter stacks in stock?

Impressive..both your testing and the improvement.
You've got one hell of a drive way
Where did you Pick you stacks up from ??
You've defiantly got my attention now...

Impressive..both your testing and the improvement.
You've got one hell of a drive way
Where did you Pick you stacks up from ??
You've defiantly got my attention now...
Sounds like the top end gain is where the stacks
Really help with performance .

Where did you Pick you stacks up from ??

I bought from these guys.

Click Here 4 More info

"But if short stacks make more power, why not just put shorter stacks in stock?"

Its not that simple, the amount of power created by the stack size varies depending on the engine RPM, if i remember correctly longer stacks are better for low end power/torque and shorter for high end power. Some motorcycles actually have variable length stacks that adjust automatically as the RPMs climb (check out the MV Agusta F4 Veltro

The stacks set (or vary) the intake length, the tuning of which is set by the intake charge flow (valve opening event) and the speed of sound. Regardless of appearance of smoothness, intake (and for that matter exhaust) flow is a stop-and-start affair which is set in motion by the valve timing and duration. At each opening and closing, a negative pressure wave moving at the speed of sound runs to the end of the intake from the valve seat and back again. If the timing of the wave going back is set to coincide with an opening event, the pressure wave going back helps to stuff more charge into the cylinder. So the overall length of the intake affects when this will take place, and thusly the rpm at which the effect is greatest. This is where variable-length intake has an advantage over fixed length. The timing of that "supercharging" event can be varied to increase power over a wide range of rpm rather than just at one specific engine speed.

Years ago, some guys were running a Norton twin in the Vintage races at Daytona. Whenever they would get up on the banking and open it up, the motor would falter and fail to hit redline. They called Leo Goff, the famous dragracer and he told them they had a midrange miss that would not allow the motor to wind out and that they needed some velocity stacks to increase the intake length. Long story short they were not able to find any to buy, so they fashioned some out of empty beer cans and were then able to get the motor to pull redline in top gear.

Hope this makes the principle behind velocity stacks clear as mud.

Just seen my post was posted twice,I'd edited it
And guess I shoulda stayed on a computer instead of
This phone....That's some good stuff there danno.great
Post and reading...I learned something there !!
I remember Hotbike magazine when I was 13 or 14
I'd gotton from an older friend and the majority of
The bikes had stacks on em. Didn't realize there's
A lot more tuning available to us
Thanks for the link too romans

Wow, those mid range ones looks great. 6ft lbs across the board almost, and besides 10k+ add about 5whp. Im adding these to my winter list. lol

I had the medium stacks which help low-end and midrange most, on my 2008 ZX14. They made a difference you would notice.