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Author Topic: velocity stack pros and cons?  (Read 19779 times)

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Offline 547

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velocity stack pros and cons?
« on: January 11, 2009, 11:53:33 AM »
what is the upside of velocity stacks and what is the down side?
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Offline shoemanII

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Re: velocity stack pros and cons?
« Reply #1 on: January 11, 2009, 01:37:59 PM »
up:  i think they look very cool.

down:  zero filtering for your engine internals
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Offline bryanj

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Re: velocity stack pros and cons?
« Reply #2 on: January 12, 2009, 01:44:28 AM »
Also down dont work with trouser leg sucked in
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Offline voxonda

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Re: velocity stack pros and cons?
« Reply #3 on: January 12, 2009, 06:04:09 AM »
up: if the right ones and a good carb tuning gain a couple of horses. Awesome sound!
down: hard to find the right ones.
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Offline Soos

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Re: velocity stack pros and cons?
« Reply #4 on: January 12, 2009, 07:19:02 AM »
DO you know how to figure the correct velocity stack for a given carb?


hrmm... off ot search the net....



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Offline Deltarider

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Re: velocity stack pros and cons?
« Reply #5 on: January 12, 2009, 07:33:11 AM »
Quote
... of velocity stacks and what is the down side?

Nothing, absolutely nothing as long as you're prepared to change your engine more often.

Recently a filterexpert informed me that when airfilter A filters out 99,8 % of the particles and airfilter B 99%, enginewear with B is already fourfold. It's your bike.
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Offline OakBehringer

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Re: velocity stack pros and cons?
« Reply #6 on: January 12, 2009, 07:37:41 AM »
Quote from: 547 on January 11, 2009, 11:53:33 AM
what is the upside of velocity stacks and what is the down side?

Filters are on all non-racing vehicles for a reason...

Don't put stacks on if you're not racing.
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Offline ProTeal55

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Re: velocity stack pros and cons?
« Reply #7 on: January 12, 2009, 07:49:31 AM »
I had V.Stacks on my old CB750 for as long as I owned it and had no issues what so ever.
Def. looked cool, but putting a real filter on your bike is always a good idea (especially if it is street driven)..
« Last Edit: January 12, 2009, 08:19:44 AM by ProTeal55 »
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Offline tortelvis

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Re: velocity stack pros and cons?
« Reply #8 on: January 12, 2009, 08:01:25 AM »
I put homemade stacks on an old XS1100 I once had and through sheer dumb luck made them the exact correct length for my setup! I used an old litho printing plate cut and rolled and then clamped on. They eventually needed replacing and I made some that were longer, some that were shorter and some that were slash cut. NONE of those worked! I used the old one for a template and again the bike ran perfectly.
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Offline turboguzzi

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Re: velocity stack pros and cons?
« Reply #9 on: January 12, 2009, 09:45:49 AM »
in theory, they should add torque at a given/planed rpm range, when they go in sinc with the intake pulses.

quite tricky to get them right though, tried a set on my racer and although they really filled a rather big dip in torque at 6000 (race cam) they caused all sorts of carburation problems up at 9-10K. cost me a race....

I believe they could be sorted with a few more hours at the dyno but am currently racing without them, too much hassle.

Current sport bikes have them built inside the airbox so it's not exactly true that running stacks means having no air filtering, you'd have to build a special airbox of course and then sort them out, playing with lengths, diameter and jetting.

I remember that someone on the forum was trying to build such a setup, he posted some cad drawings quite a while ago

Cheers
TG
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Offline Geeto67

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Re: velocity stack pros and cons?
« Reply #10 on: January 12, 2009, 11:56:58 AM »
techincally our bikes already have them inside the airbox...it is what joins the airbox to the carbs and they are made out of rubber.
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Offline voxonda

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Re: velocity stack pros and cons?
« Reply #11 on: January 12, 2009, 01:35:00 PM »
Quote from: Geeto67 on January 12, 2009, 11:56:58 AM
techincally our bikes already have them inside the airbox...it is what joins the airbox to the carbs and they are made out of rubber.

That's how I use them, pull them out of the airbox and there you have it. Work great!
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eldar

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Re: velocity stack pros and cons?
« Reply #12 on: January 12, 2009, 02:18:41 PM »
I know some have put material such as womens nylons over the openings. I suppose that is good for your average bug your rock. I think there may be some stacks that have filter caps. maybe find some of these and see what the filter medium is. If you could get oils mediums like in k&n, you might not do so bad.

I suppose the other down would be air fluctuations such as what occur with pods.
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Offline 547

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Re: velocity stack pros and cons?
« Reply #13 on: January 12, 2009, 06:18:01 PM »
thanks for the input guys. the only reason i would put them on this bike is because they are cleaner looking than filters.
they would be going on my son's '69 cb160. trying to clean it up a bit and empty out the center. been searching for a 12v-9ah sla or if it is possible to find a dry cell battery that will work.
anyhow, i think i will stick with filters. i really don't feel like replacing the engine on this bike
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Offline mrbreeze

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Re: velocity stack pros and cons?
« Reply #14 on: January 12, 2009, 07:00:04 PM »
If its not for race.........filter it!!!!
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fuzzybutt

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Re: velocity stack pros and cons?
« Reply #15 on: January 12, 2009, 07:33:24 PM »
back in the early 90's a had a 240z with the 3 sidedraft webers and stacks. there was a rubber ring around the stack that a pod filter clamped to.
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Offline voxonda

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Re: velocity stack pros and cons?
« Reply #16 on: January 12, 2009, 11:48:45 PM »
Not that good to see, but I used the K0 sidecovers to cover the stacks . Man that's a long time ago, cannot even imagine how it feld to have hair, and a few(?) pounds less.
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Offline davesprinkle

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Re: velocity stack pros and cons?
« Reply #17 on: January 13, 2009, 12:22:45 PM »
Quote from: 547 on January 11, 2009, 11:53:33 AM
what is the upside of velocity stacks and what is the down side?
Upside?  They're about an 8, maybe 9, on the Trick Parts Continuum.  Downside?  Who cares -- refer to upside.

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eldar

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Re: velocity stack pros and cons?
« Reply #18 on: January 13, 2009, 12:25:52 PM »
I dont know if cool factor alone is worth it though. the amount of work tuning and the decreased engine life certainly weigh against them.
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Offline cafe750

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Re: velocity stack pros and cons?
« Reply #19 on: January 13, 2009, 12:33:47 PM »
Who said tuning was a downside, I think its part of the fun!  ;)
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eldar

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Re: velocity stack pros and cons?
« Reply #20 on: January 13, 2009, 01:37:07 PM »
Depends on the person and your availability of tools. Besides, there is a lot of dirt on the street and no new engines being made. For some, that is enough of a downside.
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Offline cafe750

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Re: velocity stack pros and cons?
« Reply #21 on: January 13, 2009, 01:55:46 PM »
Im not arguing the reduced engine life, that is true....
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Roy, Washington

eldar

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Re: velocity stack pros and cons?
« Reply #22 on: January 13, 2009, 02:00:28 PM »
For some it is no big deal but some like to keep the bike matching.  All preference I suppose on what is good and bad. I like the looks but if I ran them, I would rig up some sort of filter system which then might negate the stacks use. :-\
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Offline Soos

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Re: velocity stack pros and cons?
« Reply #23 on: January 13, 2009, 05:21:11 PM »
questions, questions, and no time.
will post them later.




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Offline 547

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Re: velocity stack pros and cons?
« Reply #24 on: January 15, 2009, 05:11:08 PM »
is the ladies nylons idea a legit one? what about the screens i have seen on some stacks?
remember this is for my sons 1969 cb160- back and forth to school and around our small town.
no land speed trials and no long trips.
« Last Edit: January 15, 2009, 05:14:25 PM by 547 »
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