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1 Sick Individual !!
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Discussion Starter #1
Ok let me hear it. I dont have much info or experience with this part. I want to know all about it before I decide its for me. They are offered to me at 95.00. Im sure they may be less out there. Anyway, what do they do? How do they work, how is the install process. Is the benefit worth it? Also, can U use them in many racing orgs like MRA etc? And anything else I didnt think of. Post up . THank sin advance for all replies.
 

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Velocity stacks will help any bike. A velocity stack smooths the flow of air entering the carb and can also provide a stronger "sonic" ram effect. How it works. For those who care, when the intake valve opens a negative pressure wave travels up the intake until it hits the end of the velocity stack. The negative pressure wave reverses when it hits an expanding cone or opening and becomes a positive pressure wave traveling back down the intake towards the valve. If the positive pressure wave is timed to hit the valve just before it closes, then more mixture gets crammed into the engine, and you get a boost in torque. That's why the intake tract length has to be optimized for the engine rpm where you want the boost and also for the amount of intake duration. A velocity stack change the intake track lenght.

Tall = moves the powerband down
Short = moves the powerband up
 

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Of course that velocity stacks will help any bike. THAT is wy all modern bikes brings velocity stacks.
If you whant to change the velocity stacks, you have to test them in a Dyno. WHY?
Factory says that tehy sell some that make 2-3Hp in a 900ccc-1000cc bikes, With that power to fell that is almost imposible.
What a top tuner told me is that he test the R6 aftermarket VStacks and they drop power.

1- They are very expensive for the kind of gain.
2- You have to test them before you know the rigth length.

A change of spark plugs and change of good oil will make more HP.

2-3 Hp! come on, companies build that sort of thing to rip off, most of the times.
 

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Discussion Starter #5
Spike said:
Velocity stacks will help any bike. A velocity stack smooths the flow of air entering the carb and can also provide a stronger "sonic" ram effect. How it works. For those who care, when the intake valve opens a negative pressure wave travels up the intake until it hits the end of the velocity stack. The negative pressure wave reverses when it hits an expanding cone or opening and becomes a positive pressure wave traveling back down the intake towards the valve. If the positive pressure wave is timed to hit the valve just before it closes, then more mixture gets crammed into the engine, and you get a boost in torque. That's why the intake tract length has to be optimized for the engine rpm where you want the boost and also for the amount of intake duration. A velocity stack change the intake track lenght.

Tall = moves the powerband down
Short = moves the powerband up
Im impressed. SO much information. Had to read it more than one time to understand. haha Thats what I was looking for though. TO make an informed decision I needed to know what the purpose, gain,value was.
To be honest I dont have access to a dyno for repeated testing so I may not be able to find the right size etc. Perhaps I should consider other options.
I did manage to find out that most racing orgs dont allow changes to this. So I may not be even able to do it anyway.

Thanks all for your input.
 

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Marcos Peguero said:
Of course that velocity stacks will help any bike. THAT is wy all modern bikes brings velocity stacks.
If you whant to change the velocity stacks, you have to test them in a Dyno. WHY?
Factory says that tehy sell some that make 2-3Hp in a 900ccc-1000cc bikes, With that power to fell that is almost imposible.
What a top tuner told me is that he test the R6 aftermarket VStacks and they drop power.

1- They are very expensive for the kind of gain.
2- You have to test them before you know the rigth length.

A change of spark plugs and change of good oil will make more HP.

2-3 Hp! come on, companies build that sort of thing to rip off, most of the times.
Marcos Peguero you might think that Velocity stacks are a scam but that's because you don't know what the proper usage of them is. Ask your "top tuner" if the bike lost power at one point or through the entire powerband? He probally put the long stacks in and lost power up top so that mean that they are garbage because everybody needs more power up top right:D
It's not really about making MORE power it's about changing the powerband of a bike. Sometime you need alittle more grunt down low to get off a low-speed corner. One of the tracks I race at the last corner before the front straight super tight at first and the widens out and if you downshift into first coming in it you loose entrance speed and you have to shift while leaned over. But if you leave it in second the motor goes below it's powerband and you get a shitty drive onto the straight. I lengthened the stack height in practice one time and the drive I got off the corner was far better then before. I lost some top end power but I don't rev my bike all the way up because it doesn't power past 13000rpm. I might not of seen a peak hp gain but I did see a gain at 7000 rpm. So it all really depends on what you want and where you want it.
 

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Then you agree 100% with me....
on point 2.

You have to test them.

My point is very simple. Drop in kits or aftermarket things are not a panacea.
I have seen people in many forums think like

Catchup + 2 Hp
bread in the gas +2Hp
mill head + 15 Hp
ginger + 3 Hp

then I will have in my bike 22 Hp more and you seem to know that is NOT even close to the truth.
 

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Yes I agree with you on the second point you made. It's also true that just because someone says that it will make more power doesn't mean that it's the truth. But as for Velocity stacks being a scam and that they lose power that's not true. And yes 2-3 hp does matter on the track.
 

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Discussion Starter #9
Spike said:
And yes 2-3 hp does matter on the track.

Got to agree there. Not to sound goofy but " It dont matter if U win by an inch or a mile....Winin' is winin'!!" (Cheeky movie Quote) hahaha
 

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On the track only.

I think that they are very expensive for the kind of Hp your getting and + you have to dyno them to make shure your going the right way.

There is a lot of moods that I like more.
 

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Marcos Peguero said:
There is a lot of moods that I like more.
Such as?
 

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Discussion Starter #13
Well for me I would say track. I am hoping to get into some sort of racing org next year or the year after. Many I am finding do not allow this mod. So It may not make a difference anyway. Now for the street bike. Serious possibilities.
 

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I like smaller intake ports

cheap work and lots of power

Shure that works on ZX6-9, old and new gixer 750, R6-1.

Cost
4 tubes of JB weld 20
head gasket 60
asembly grease Red line
lap the valves very good

take ot the base gasket


ww.mototuneusa.com
 
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