Exhaust Q
 

Hi all, I've got a 2011 Daytona 675, and I was about to get an aftermarket exhaust system installed.
It is one by 2 Brothers. I was wondering, what kind of gas mileage changes to expect?

There would be very little change to gas mileage.

For modern sportbikes, just changing the exhaust system without reflashing the ECU won't change much. The bike will sound better and backfire occasionally, but to get your money's worth get the ECU changed to fit the new exhaust system.

My R1 has about 20hp more than stock, and the gas mileage is about 3mpg less than stock.

Nice, 20hp is decent increase, sir!
What kind of exhaust do you have on your R1?

Instead of buying a full exhaust system from one manufacturer for $3,000-$5,000; I just bought different parts for cheaper to make it a full system. My titanium headers are stock, but I replaced the catalytic converter with a straight pipe, it is called a "Y" pipe and it's made by MJS. This part was around $270. The GYTR mufflers were installed by the previous owner, but they usually go for $1,000 for both. So this way I have an exhaust system that is third of the cost and 90% as good as a full system.

Reflashing the ECU has a lot of other benefits in addition to more horsepower. The throttle response is smoother and the engine now revs to 14,500rpm. The stock engine map has dips and spikes due to noise and emission regulations, but the ECU tune gets rid of all that (the trade off is worse fuel economy).

If you want your engine to have a lot of horsepower and a good sound, install a K&N or BMC air filter, install a nice exhaust and then flash the ECU to suit those modifications.

Here are some pictures, the black pipe is the catalytic converter. The shiny pipe is the "Y-pipe" and I mailed my black ECU to ECUnleashed where they cut it open and loaded a better map. For a few hundred dollars more, they offered me to install a cruise control and have assigned buttons that I pick for control; but I didn't want to do that. The flash cost me $570.

That's an impressive build for the impressively low cost, sir!
I have bought my Daytona 675 about 3 months ago, so didn't have a chance to investigate it well enough, to my regret. Yet the muffler is something that has to be replaced, as looks like something burnt out in the original one. So I thought this was a good idea to get a new one installed. I found one by 2 Brothers, and I liked the way it looks, the way it sounds, you know. https://www.motorcycleid.com/images/...structions.pdf Here is the one. Yet, I've read that these mufflers may boost fuel consumption and even can be illegal to use, so I thought people here at Fuelly will tell me something they know about it lol
However, I think that replacing a muffler only is not likely to change anything badly, right? I plan on replacing the whole exhaust, but that's a project for spring, as I have already spent $$ on my bike and got a Tesla Model 3 which is also a kind of vehicle expenses. I am not saying I cannot afford it, just like you said, if there is a way to build an exhaust rather than but an expensive one, I'd rather work on it and save a bit, you see...

You should have no issues with installing the Two Brothers muffler or a full exhaust system. Texas doesn't have emissions testing. Some of the modifications on my bike were done because I saw other people doing the same mod from Houston Texas. Although I'm from Canada, I was reading Sport Rider for 20 years before it got discontinued last year; the magazine had everything on sport bikes and it was from the US.

California is the only state that is strict about people modifying their bikes and cars. If you live there and you want to replace your muffler with an aftermarket one, the aftermarket muffler has to have a tag on it saying that it complies with EPA regulations for noise and it meets the 80 decibel maximum sound. I think only Yoshimura and Akrapovic are the only muffler makers that make mufflers that come with this tag.

You should check out other mufflers as well, the Two Brothers is a nice looking muffler, but Leo Vince and Arrow also makes nice mufflers for this bike. Also, having an integrated tail light will clean up the back end of the bike nicely. Here are some of the pictures that I saved when I was planning on getting a Daytona 675. I ended up getting a Buell Firebolt instead with all the modifications already on the bike.

There are a lot of videos on how to install mufflers to the Daytona 675; so installation should be very simple. The motorcycle community gets away with a lot more than the car community when it comes to modifications, unless you live in California. With all the money you are saving on fuel by driving the Model 3 you can spend it on your bike ;) BikePics is a great website to check out pictures of your bike and see what kind of modifications people have done.

I appreciate your help and posting the pictures, sir.
Yea, I know that all those restrictions and CARB requirements are normally about California with all their 'green' laws and stuff. Texas government is not that strict in terms of getting vehciles modded. I was looking at the description of the Two Brothers muffler online, and saw the text, saying:

This is a Race Only product that is to be used solely for competition. It cannot be used on vehicles that are operated on public streets, roads or highways. Its use is limited to closed-course and open-course racing that is formally sanctioned by a recognized racing organization. Any other use, including recreational off-road use, could be in violation of local, state and federal laws. (here's where I saw it)

I liked the price and liked the fact that this exhaust is carbon fiber. Yet when I saw the note about federal laws, i thought there may be something about this muffler that violates some kind of federal laws. That's why I asked here, thinking that people here know more than me about such kind of mods and stuff. And, I was lucky to talk to you, sir.


I will look into the mufflers by these 2 brands tonight, thanks for the recommendation!

I am attaching the pic of my Daytona 675, as well as the pic of that CF muffler by 2 Brothers I was thinking of from the very beginning.

Nice bike, I remember seeing this color in the showroom a while back, I still remember the gorgeous paint job with the blue flakes; one of the best factory paint jobs I have ever seen.

If you go with the Two Brothers exhaust, the M2 is a smaller pipe than the M5; that's the only difference between the two. The M5 is more oval shaped. I think the M2 looks better, that's what is shown in the picture that you posted.

Good luck with the install and ride safe!

Appreciate all your help! I'm glad I had a chance to chat with you, sir!