I've been a sportbike rider for years andjust bought my first Harley. I'm loving it but really miss the 70 horsepower extra that my other bike makes. So, I want to maximize my dyna's performance. However, I really don't want a very loud exhaust.

My question is, why does it have to be loud? I realize that the displacement of my Harley (1584cc) is larger than a 1000cc sportbike, but the sportbike can produce 150 rear wheel horsepower through an amazingly quiet single exhaust can.

Why can't they make cruiser exhausts capable of 150 horsepower that are quiet, expecially since dual exhaust cans are the norm?

 

Quick additional note: Please don't turn this into a Harley versus sportbike war. Like, why did you buy a Harley if you want to go fast? Thats not the point. I'm really interested in a discussion on why a cruiser exhaust can't support big horsepower unless it rivals a jet taking off in noise level.

 

Try a Supertrapp supermeg 2:1. Not loud and a good performer.

 

As you pointed out, hp doesn't require loud pipes. But how well do you think a big can at the end of a quiet pipe is going to sell to average HD ppl? Harley's sound good and ppl buy not only the bike, but the sound and the vibe.

 

CKinAZ,
I agree that most people like the louder sound. But you would think that a large aftermarket exhaust manufacturer like Vance & Hines, who already make 10 different exhaust options for a given Harley line would produce an 11th model for the rare few who don't want loud.

Also, the exhaust can on a 2-1 system like the D&D Fatcat is pretty large. I would think sufficient baffling could exist in that size of a pipe.

 

the one big advantage ofthe Super Trapps system mentioned , is their baffle system! They are very easy to tune. In other words, if the pipes are to loud take out some plates. I've had Super Trapps in thepast myself, and in my case I had at the time, Slip-on's along with tips that curved towards the ground.seems to put the sound behind you.I understand what your taking about dealing with loud pipes, I'm not found of it myself.Go on line and check out Suppertrapps or better yet get the catolog. The catolog gives you a better picture on all the different configuations.

 

It can. A Fatcat with the quiet baffle is much quieter than any V&H pipe, including those with the V&H quiet baffles--and delivers better performance to boot.

 

The sport bikes engine design and performance is almost a polar opposite to the HD Twin. The larger sport bikes use more cylinders, overhead cams, and are very high rpm motors. They are very light weight in comparison to the horsepower that they develop. The use of multiple smaller pistons allows smoother power pulses. The exhaust note on the sport bike is a much higher pitched whine. The HDs are 45 degree twin cylinder large displacement pushrod activated OHV engines. The red line is less than 6000 rpm in stock configuration. The engine is designed for high torque at lower rpm. The HD touring bikes are large heavy machines that carry two up and baggage. Just by nature of design the HD twins are going to produce a lower, heavier exhaust note. The performance exhaust on an HD engine has to move a lot of spent gasses produced by two large displacement uneven firing cylinders. To allow the large displacement 45 degree twin to effectively produce power, a relatively free flowing exhaust system matched to the engines configuration is required, and that generally means a louder than stock exhaust note. As noted the loudest exhaust may not be the best power producer, the exhaust system has be tailored to fit the engine build in order to produce the best results and indeed some systems are just louder than others.

Arcane

 

WOW....well explained!!

 

These look interesting , although I've never heard one.
One guy in the bagger forum has one and loves it.
http://www.rbracing-rsr.com/lsr21blackhole.htm
I would like the same thing , but the manufacturers target the louder is OK crowd..
The D&D Fatcat with quiet baffle sounds like a winner also.
I'm stuck between these 2 myself.
Mick