When one bung is not enough.

[Yukonf3]

Add another. Ready to start fitting and measuring various exhaust configs.

[Bob Denman]

What is it, that you're going to be experimenting with?
Good Luck!

[garb55]

What is it, that you're going to be experimenting with?
Good Luck!

He needs more than one bum
oh
I mean bung .

[Yukonf3]

What is it, that you're going to be experimenting with?
Good Luck!

I've got a wide band o2 sensor and air fuel ratio data logger. Going to see how the current ECU is tuned and if or how it reacts to various exhaust configs from stock to a complete new system with flow through muffler.

I've confirmed that the stock exhaust system is pulse tuned, so will be interesting to see the effect of changing that as well.

Also have a connection adapter that will allow me to measure the exhaust back pressure of each. I'll be paying particular attention to the effect of the primary muffler / cat unit as well as baffles etc. For example, I suspect the Two Bros P1X power tip that is recommended to reduce noise is choking the $%^# out of the system.

I also have a sound meter so will compare sound levels of the options.

Why you ask? All to better understand the existing dynamics in the quest for a strong performing exhaust that is not too overbearing in loudness.


cheers,

[SteveLaoyster]

I've got a wide band o2 sensor and air fuel ratio data logger. Going to see how the current ECU is tuned and if or how it reacts to various exhaust configs from stock to a complete new system with flow through muffler.

I've confirmed that the stock exhaust system is pulse tuned, so will be interesting to see the effect of changing that as well.

Also have a connection adapter that will allow me to measure the exhaust back pressure of each. I'll be paying particular attention to the effect of the primary muffler / cat unit as well as baffles etc. For example, I suspect the Two Bros P1X power tip that is recommended to reduce noise is choking the $%^# out of the system.

I also have a sound meter so will compare sound levels of the options.

Why you ask? All to better understand the existing dynamics in the quest for a strong performing exhaust that is not too overbearing in loudness.


cheers,

Sounds like a real good idea. Keep us posted with what you find. You've got me interested.

[Yukonf3]

Had a chance to play a bit with the stock exhaust vs Two Bros. Gotta say that the stock exhaust is not that restrictive even with a cat and constriction of the pipe down to 1.5" at the secondary muffler I have a sensitive pressure gauge but was only picking up 1-2 psi at the most.

Two Bros didn't register, and given that it is straight through 2" pipe all the way, didn't expect it to. Will have to use a manometer to get some finer measurements as I start to compare cat bypass and various tips on the straight through muffler etc.

Also ran my Innovative wide band logger. I can confirm that the bike runs 14.3-14.8 to 1 air/fuel (stoichiometric is 14.7:1) at idle and steady state rpm through the range to 4K on both exhausts. I did pick up 13 to 1 with throttle blips but hard to confirm exact figures....I will run some under load tests later to fully test but it appears the ECU works well with stock and after market.

As for sound, the stock registered 93 db at idle and 103 at 4K, measured at the standard 45 degrees / 50 cm from exhaust exit. I had some reverb from the houses so probably slightly higher than an open field test. Legal levels are generally 92 db and 100 db respectively.

Two bros was 103 at idle and 110 at 4k. For reference, intensity doubles every 3 db and loudness doubles every 10 db. So yes the two brothers is twice as loud and significantly more intense. The biggest difference is the tone. The Two Bros perforated bore muffler attenuates the middle to higher frequencies but the lower ones come through a lot and seem to carry more. I'm going to do some 10 and twenty feet measurements, where I'm sure the difference will be even greater.

More later.

cheers,

[Deer Slayer]

Like ya post. I fiddled with my RS-S stock muffler as I knew the stright thru mufflers were just too high pitched. I cut a slot in the bottom cleaned up the inside, making a chamber. I the added 1 and 5/8 pipes on the end. Result is a low pitch boomer with better flow. I think it sounds better than the $900 BRP one. Carry on.

[Bob Denman]

This looks to be a very interesting experiment!
I'm looking forward to seeing your results, and suggestions!