TOPIC:

So, do the "expansion chambers" in the exhaust system serve any purpose other than noise reduction? Noise reduction is not necessarily a bad thing, per se, but my inclination is to replace the chambers with an s-bend, and the "cannons" with a pair of Sportster mufflers like I did on my '77 naked Gold Wing.

One of the guys over at the KZ1300 Facebook page told me that 4-strokes don't use expansion chambers.

The term :expansion chamber " in the exhaust world usually refers to the part of a 2 stroke exhaust system that creates a negative pulse to pull out the exhaust and then create a positive pulse to stop the flow of intake gases from following the exhaust gases out of the cylinder. What your talking about are the collector boxes on the ends of the header pipes that collect the exhaust and reroute through a single pipe to the mufflers. The collectors act more like resonators in a 4 stroke exhaust system, merging the pulses and if properly designed help reduce the peaks of the pulses which will help cancel out the noise at certain frequencies.
The inline 6 cylinder engine is the perfect engine for a 6 into 2 exhaust system and when designed properly can add some significant horsepower. Also, a 6 into 2 into 1 will add more than a 6 into 2 but the work involved is also significant. The only major saving is the weight of the system and the sound difference .

A good read if your into it is this book. scientific design of intake and exhaust systems by Phillip H Smith.

I have kept a copy of this in the workshop for YEARS. At some point, God willing, I will do a system for the bike. House reno are stalling out my "shop time" right now. 1600 ft of hardwood going down, new kitchen to install in 2 weeks then 2 bathrooms to gut and rebuild and convert a 2nd bedroom into a walk in closet. Funny how life gets in the way but you do what you have to to survive.

"cannons" with a pair of Sportster mufflers like I did on my '77 naked Gold Wing.

I attest to this, as my '83 Wing has Sportster pipes. Works and sounds well.

I've had that book for years too! I just thought it was funny to be so thoroughly misunderstood.

Kawboy wrote: House reno are stalling out my "shop time" right now. 1600 ft of hardwood going down, new kitchen to install in 2 weeks then 2 bathrooms to gut and rebuild and convert a 2nd bedroom into a walk in closet. Funny how life gets in the way but you do what you have to to survive.

I feel your pain. I just finished installing a new shower cubicle and that took me four weeks (although two were delayed delivery of the acrylic sheets I used for two of the walls).

So all those CBX-es I see on Pinterest etc with six into six actually have less BHP than a standard 6 into 2?

Paul