Does anyone have this velocity stack mounted on their bike?
#22
Join Date: Dec 2004
Location: Texas! Ya mean there's someplace else?
Posts: 11,065
Received 1,296 Likes
on
483 Posts
RE: Does anyone have this velocity stack mounted on their bike?
Sigh ... I guess today is my day to take a crap in the parade.
One reason a velocity stack works for performance is by the decreasing diameter causing an increase in air velocity as it enters the throttle body/carb mouth. Higher velocity air helps with air/fuel mixing for one thing.
By sticking the filter element shown in the pics into the velocity stack the flow is going to be significantly disrupted. It may provide some of the improvements associated with the stack, or it may give less flow than the stock can. Only way to tell is to see some flow stats on the thing.
If I had to make an educated guess on what the flow profile looked like, I'd expect to see quite a bit of turbulence at the back of the stack where the stack, filter, and carb/throttle body meet. This turbulence would not be a good thing. The air passing through the filter would be slowed by the many direction changes undergone, while some of the air outside the filter would slam into the back and try to come back outward (action/reaction), and yet another portion would make its way into the filter.
Show me the money - flow profile, flow volume.
For looks? Yep, looks pretty cool.
But in my world, form follows function.
One reason a velocity stack works for performance is by the decreasing diameter causing an increase in air velocity as it enters the throttle body/carb mouth. Higher velocity air helps with air/fuel mixing for one thing.
By sticking the filter element shown in the pics into the velocity stack the flow is going to be significantly disrupted. It may provide some of the improvements associated with the stack, or it may give less flow than the stock can. Only way to tell is to see some flow stats on the thing.
If I had to make an educated guess on what the flow profile looked like, I'd expect to see quite a bit of turbulence at the back of the stack where the stack, filter, and carb/throttle body meet. This turbulence would not be a good thing. The air passing through the filter would be slowed by the many direction changes undergone, while some of the air outside the filter would slam into the back and try to come back outward (action/reaction), and yet another portion would make its way into the filter.
Show me the money - flow profile, flow volume.
For looks? Yep, looks pretty cool.
But in my world, form follows function.
#23
#24
RE: Does anyone have this velocity stack mounted on their bike?
If you just want looks it will work for you. If you want performance thatpiece has got to be a dog, it completly defeats the purpose of a velocity stack and the filter is so small it couldn't possible flow enough air to keep a lawn mower happy.If the velocity stack where inside the air cleaner notinstead of the opposite it would word great.
#25
RE: Does anyone have this velocity stack mounted on their bike?
Yeah in the High Performance automotive world if there's a filter on a velocity stack it's usually on top of it, not inside of it... and those are usually mounted on top of a tunnel ram intake.
Makes total sense that it wouldn't work well.It still looks cool. If it cost's performancethan I'll pass..
Makes total sense that it wouldn't work well.It still looks cool. If it cost's performancethan I'll pass..
Thread
Thread Starter
Forum
Replies
Last Post
128auto
General Harley Davidson Chat
6
12-07-2014 07:09 PM
metaphysician
Softail Models
13
08-20-2012 06:54 PM