After mercury velocity stacks

[joshlindsay1990]

Looking for Mercury v6 velocity stacks

[John.Richardson]

Hi mate,

Do you mean the black flame arrestors from an xr2 which feed into the airbox and curve around the engine?

[joshlindsay1990]

No the ones that go around the carbs with no airbox on so it looks

[grandmas denture]

Bob's Machine Mercury V-6 Velocity Stacks

[joshlindsay1990]

Cheers grandma ����

[Budski]

Apart from looking cool, these are a complete waste of time. If you are combining these with some "exhaust work" don't forget to richen up your jets otherwise you will run lean with unfortunate results.

[joshlindsay1990]

Ok well I'm running my merc with no airbox and thought attaching velocity stacks then it would rush the air in directly instead of hitting the carbs and around the end, but cheers

[roflhat]

As opposed to running nothing at all, e.g. air box, filter. There is a significant gain to be had from running velocity stacks, especially on an outboard where almost all the intake air comes from behind the carbs. Having a large radius on the outside of the stacks is critical

Even from a non scientific point of view it is clear to imagine how the air flow compares between a sharp 90 degree edge in the case of no stacks to a smooth radiused curve with stacks.

[Budski]

I speak from experience, not just theory.

[grandmas denture]

... yup, upjetting is definitely necessary

[roflhat]

There is no doubting the fact that stacks can improve performance, look at dyno results, they will show you that they work