Velocity stacks
- Thread starter aowash
- Start date
for your mods just put in 4 stock short stacks.
I've been thinking of going with velocity short stacks. Right now I'm using my oem stacks with the long ones cut down. I'm still debating on switching to all short velocity stacks but haven't heard anyone convince me it's worth the money. My cut ones no longer have a flare but does it really matter? hmmm.
Yep it matters.
THANK YOU, Rick. I NEEDED a credible source to tell me that.
Take a funnel and pour water through it both directions and see what works better. Extreme example but the flare is a very important part of the total flow. There is much work put into the design to make it flow better. Even a ding in the metal ones can impede the flow numbers.
mike1180
Banned
I use 4 long stacks from Factory Pro:
http://www.factorypro.com/
They are a bit of a challenge to install in the airbox, but it can be done.
They work awesome, right through the whole powerband.
Seemed to add some real juice to the bike.
Add a nice growl/howl sound too, when you open her up.
http://www.factorypro.com/
They are a bit of a challenge to install in the airbox, but it can be done.
They work awesome, right through the whole powerband.
Seemed to add some real juice to the bike.
Add a nice growl/howl sound too, when you open her up.
dolilind
Registered
+1 on 4 small stacks that are the same size.
aowash
Registered
So 4 short stacks seems to be the way to go. My friend was trying to convince me to use 2 short and 2 long stacks, but that just didn't seem right. When I checked, for max torque and Hp it seems that the 4 short stacks is the answer. Have any of you tried different combinations to see what is the best?
2-short, 2-long is stock.
If you need short stacks, I have them. $20 TYD.
mike1180
Banned
Here is part of an article I found with one answer for the size of stacks.
Enjoy!
http://www.schnitzracing.com/manuals/TechArticle-HayaStacks.doc
The optimum set up for your bike depends on the modification of the bike and your objectives. Some general guidelines are:
41mm stacks- Best used on highly modified engines long duration cams with 4:1 exhaust, where horsepower at high rpm is desired.
2 x 41mm + 2 x 72mm street stacks- Best used on relatively stock bikes where the stock torque band is retained but improved.
60mm stacks- A compromise between the former two combinations. Works well with stock bikes and modified bikes. It will provide improved hp in the mid to upper rpm band.
Enjoy!
http://www.schnitzracing.com/manuals/TechArticle-HayaStacks.doc
The optimum set up for your bike depends on the modification of the bike and your objectives. Some general guidelines are:
41mm stacks- Best used on highly modified engines long duration cams with 4:1 exhaust, where horsepower at high rpm is desired.
2 x 41mm + 2 x 72mm street stacks- Best used on relatively stock bikes where the stock torque band is retained but improved.
60mm stacks- A compromise between the former two combinations. Works well with stock bikes and modified bikes. It will provide improved hp in the mid to upper rpm band.
aowash
Registered
Just another question before I buy these darn things. Is it true that short stacks help torque and power at the low end and the long stacks are for horsepower at the top end? I really don't know, I see the what you posted for optimal setups but you said that you have 4 long stacks, did it affect your torque at all at the low end, cause if it didn't that seems like a nice setup.
mike1180
Banned
I have 4 of the 60 mm stacks. That is what I meant by the "long ones."
I don't know how it would work if you used 4 of the 72 mm ones. I don't think you can even buy that combination.
When I started doing my mods, I really didn't need any more power, for just power sake.
These things are plenty fast enough stock. I wanted to level out the power throughout the range, and have it hit a little harder right off the bat. With what I have done it works very well for me. My Orient Express full Titanium Sumo exhaust and PCIII, made a huge difference and with the Pair valves removed, stacks, K&N with a full air box mod all added nicely.
I would say that with what I have done, my power is strong right through the range from bottom end to top end. There was a very perceptible improvement in the mid to high range, but the lower end is really strong too.
In reading some of the articles about all of this, you could become a fanatic about tuning these things, and everything that you change affects everything else.
When I walk on this thing at any speed up to 50 mph or so, from a rolling start, I can't keep the front end on the ground. Do I need more power than that? "¦probably not.
Even if I got it, once the front end is in the air, how could I use more?
I like to go fast through the corners and love how it handles, so I don't want to go the extended swingarm route
I think you should be fine with the 60 mm stacks. The do work, and did add to my overall results.
JMO
Mike A
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