This Sucks

[The Stranger]

Factory Pro velocity stacks.
Do they make a difference? you hear all sorts of stories about velocity stacks. some say they make no difference, some say they effectively rob power from one area of the rev range and move to another and the manufacturers all claim they add power and that their design is the best.

So it was with a little apprehension that I handed over my money for a performance part that may or may not have any benefit, or rob me of low down torque, which is already a little lacking on the Fazer.

But I must admit, I am somewhat surprised to find that they do perform pretty much as claimed. Using the butt dyno, there is a little more power down low and in the mid range, not much, but an improvement.
The Fazer is pretty laxidasical below 7,000 rpm, but you get a real hit at 7 that peaks at 9. Factory Pro claim an additional 5-6 hp between 9,000 - 12,000. Now that hit at 7 just keep going.

[James Deuce]

Nice Jandals!

I've been looking at some for the Zed, but must do the Power Commander first.

[The Stranger]

Nice Jandals!


Great to see someone else whom appreciates quality footwear, it's bloody hard to find good jandals these days.

[sAsLEX]

Do they make a difference? you hear all sorts of stories about velocity stacks. some say they make no difference, some say they effectively rob power from one area of the rev range and move to another and the manufacturers all claim they add power and that their design is the best.


Well they do affect power according to their length, you want long at low revs and short at high revs, Yamaha have made some that go between long and short for the differing rev sections, but this is a two stage system which is lazy engineering as if they were adding the weight of a linear actuator they should of made a continuously variable length....

[xwhatsit]

Most carbs these days come with a sort of tapering diameter throttle body anyway, so you'd expect the main benefits to be a sort of tweaking of where that extra boost comes along. In the old days with dead-straight carb bodies, probably a much bigger effect by gluing a set of those things on.

Keihin's CR Special racing round-slides come with plastic trumpets as stock. You can get them in different lengths for different situations. So the theory is not bullshit, just the implementation might be if the manufacturers don't know what they're doing (like exhaust system manufacturers, noise and looks before performance).

[bugjuice]

I've seen them for my bike all over the place (in the US), and no one has said they don't do squat. I've thought about getting them for mine, supposedly working better at the higher RPM