The Yamaha Road Star Warrior Forum

So Im looking through the Exhaust Photo Thread and I notice that some of you guys run staggard pipes to the point the rear pipe is MUCH shorter than the front. Maybe im old school or maybe im misinformed but I thought it was VERY important on a V-Twin to have equal length pipes... no?

Unless you're tuning for maximum gain equal length pipes aren't as big a deal as one is led to believe.  Heck many cruisers with a factory 2-into-1 system or duals with a crossover don't even have equal length headpipes.

Tuned pipes are more important than equal length.  Tuning can be done by using different ID's for each head pipe, or different steps in each head pipe in a step-header design.  That being said, I agree with Dguy that equal length is not as important on the street, a few inches here and there.  It helps save manufacturing cost to have both pipe ID's (and steps if any) the same. 

If you read-up on exhaust scavenging you'll get an idea of how much they could be different and not cause a lean condition in one jug and rich in the other (LOL it takes more that you'd think).

I don't know if the majority of the duals have crossover tube or chamber, my Muzzy duals do. I believe the purpose of cross conection has the effect of balancing the two pipes to get the same back pressure and caracteristics.

Its becoming more common for 2-2 pipes to have a chanmber but many do not.  I agree I think it helps.

youngja:

I don't know if the majority of the duals have crossover tube or chamber, my Muzzy duals do. I believe the purpose of cross conection has the effect of balancing the two pipes to get the same back pressure and caracteristics.

Its more important on a carbed bike when the cylinders share the intake manifold.

My pipes were advertised as having equal length heads. Thats why there are so many bends.

They never once mention how this would effect the performance but they say it gives it a more tuned sound. (like I would know the difference)

Anyway, my point is that if a manufacturer isnt trying to take advantage of the difference between equal length vs diff length than there isnt much of a difference at all. Did that make sense to anyone? lol

Excellent point.

Churchkey:

Its more important on a carbed bike when the cylinders share the intake manifold.