Dyno charts for Custom Cruisers - S&S?

[robwbright]

Dad just got a new (used) custom cruiser - see pic - with an S&S motor. He doesn't like the pipes on it and is looking to replace them with stepped Vance and Hines pipes.

Any ideas for finding comparison dyno charts for cruisers? I did a quick search tonite and found a few charts, but nothing with comparisons. . .

Or, any ideas as to how much HP gain he might get? 5%?

 

[FruDaddy]

Some of the better pipe manufacturers have dyno charts on their web sites, but most build their pipes for 2 purposes, asthetics and noise, and don't even care about power output. Most bikers believe that the extra noise is power, and power percieved in more pipes sold.
You could also check out the magazines, they often do shootouts.
I have found that a well placed K&N make a huge difference in power, and required rejetting the carbs, on my street bike. The pipes were far less significant.

 

[robwbright]

Thanks. I kinda figured that was the idea. I don't know what dad's really after - he hasn't even had it on the road yet - he's not getting it registered until spring - and he's moving up from a 1200 sportster.

It does certainly sound like it's got more power than the sporty. . . ;)

 

[02yz426f]

I have heard that stepped headers restrict power and smaller exhaust pipes= more power. I know this goes against popular belief, but I will post the website if I happen to find it again.

 

[FruDaddy]

I think that is true if you are only talking about HP. As I recall step headers improve bottom end torque at the expense of top end power.