6" Velocity stacks

[StrokerMcDell]

Is there any advantage in fitting a pair of 6" velocity stacks on my DellOrto 40 DHLA in place of the normal 2" ones?

[red baron]

plain and simple. more low end torque.

I don't know how much, but there will be more. But you loose power and high rpm.

[StrokerMcDell]

Bought them and they are brass machined from a billet (guy who made them must have worked in a shipyard or something)
They are actually very nice well machined with wide mouths and parallel sides.

So now I ve found a use for the cheap 6" filters that I bought a few years back 

Anyway, I'll have to shorten them and braze them back together to fit under the filters ......
Is there an optimum length for V. Stacks on a 40mm Dell Sidedraft on a 2165cc - 275bhp dragrace only engine ?
or
Should I just stick with the 2" ally ones?

Regds

[John Rayburn]

It doesn't change horsepower, just where your tune is. The longer the stack, the more bottom end, and it won't RPM as high. Shorter length, and it comes on later and RPM's higher. Optimum depends on what you are going to do.  1/8th mile would be better with the long stacks, 1/4 mile with the short stacks.

[StrokerMcDell]

I dont think these stacks will be remotely useful for any performance improvement but damn ... they look good!