Gutting the secondary muffler

[mbfj40]

A question for consideration. I have a programmable ECM on the way from IDS to better tune the bike for the occasional track day. I know I can "secondary delete" safely with the IDS but I street drive as well and am not liking the extra loudness of leaving the secondary off 100% of the time. I know that the secondary muffler has one of the tubes as a resonator for mid-range or drivability or what not. But it is clearly not in play with the secondary-delete, and everyone seems to like it.
So..........
In concert with the IDS ECM, I was thinking about modifying the secondary for the resonator pipe to be open for both pipes to exhaust. So it would be like the dual open on the secondary-delete, except that it would all go through the secondary for a little less noise. I've heard a comment or two from others who have done the same and were happy, but I've got no specifics from them.
I would probably look to buy someone's take off secondary for modifications and keep my original for swap back to stock if ever needed.
Soooooo.... what's the thoughts?

Mike

[EBRRider]

Good question , Mike , you are just north of me , Iam in Fresno.

[d_adams]

It's called "quarter wave tuning" and it's specific to this bike. Sounds travel at one speed, gas at another, but they do interact with each other. Reversion is what happens, so the sound wave from one pulse hits the actual gas wave from another. Timing is everything. If you plan to pursue it, I'd suggest getting a dual wideband O2 sensor setup and plan on spending a LOT of time (and possibly money) tuning it. I won't go into full detail, the information is out there online, you just have to weed through it or go to school and learn it like I did. Engineers come up with some really nifty stuff on occasion, this was one of those things. Try getting an 1199 ducati to get 50+ mpg and still put down 185 hp at the crank, I'd bet money against that happening.

[mbfj40]

I understand the quarter wave resonance tuning 100%. My question is that if there is a performance gain by doing a secondary delete with proper tuning, could I, with proper tuning see a performance increase (perhaps not as pronounced as the secondary delete) by still using a modified secondary to keep the db increase to minimum.
Obviously the secondary delete with tips completely eliminate the quarter wave tuning. So if there is no gain other than noise why bother other than weight reduction? Clearly the secondary keeps EPA noise levels in check and the quarter wave would help street drivability. Perhaps the delete and tips only add on the top of the rpm range and would only benefit at the track leaving a big hole in the midrange? Is that the case?
Also was planning a full dyno mapping for whatever ends up on the bike

[d_adams]

The secondary delete kit nets only a few hp at best at any given rpm. No losses that I'm aware of though, other than fuel mileage will suffer, possibly 15 mpg or more but that all depends on how you ride the bike.
The exhaust as a whole unit is designed to meet epa regs for noise and fueling. Not knowing exactly what you plan to modify inside the primary can leaves way too much on the table to speculate about. It's a helmholtz resonator setup, so altering it will have drastic effects.

[mbfj40]

So do the secondary delete w/tips also lose 15 or more mpg?

[d_adams]

It all depends on how you ride it. If I get 30-35 mpg out of mine, I'm doing pretty good. I do run it hard though. Can't lean it for shnizzle, but I do run it.

[mbfj40]

I'm not too far off that milage with the secondary in place. Was just looking to take advantagem (if any) of the secondary delete and proper tuning, but just have the now dual tips exit through the secondary like a two into one to drop the db a little. If there's no advantage, it's not worth the effort.

[mbfj40]

With no more advice on this project, Is there a secondary muffler out there on someones shelf that can be had inexpensively to experiment with?

[86bgn]

With no more advice on this project, Is there a secondary muffler out there on someones shelf that can be had inexpensively to experiment with?

I am curious about this too....

I have a ECM for removing the secondary, but when I put the stock stuff back on, I know it is stronger in the mid-range. I thought about putting on the Race ECM and leaving the secondary muffler, but when i asked if anyone had tried that, all i got back was why. Personally i like the bike better with the stock set up, the mid-range feels stronger, and it does not create unwanted attention from the po-po's

If i could have the secondary muffler, with the race ECM, i think that would be a pretty sweet combo....