Two slip-ons better than one ?

[DING]

Hi, everyone ! Stock exhaust is way too heavy. So I recently got a new Akapovic full system single slipon.
That thing sounds so nice. But I am still a big fan of duo slipons.
So here is the question : are two slipons better than one ? from aerodynamic aspects.

And here are some additional questions
1. Why do many ppl put the handle on the cowl ?
2. What swingarms u guys are using rightnow ? My desired extended length is like 3-4 inches.

Thanks everyone.

 

[Hayabusa Wannabe]

are two slipons better than one ? from aerodynamic aspects.

I do not think anyone can provide a definite answer. I see two things at play and both would merely be a factor at extremely high speeds in my opinion.

Aerodynamic drag is a function of the square area as seen from the front of the bike. Anything that sticks out to the sides generates drag. Thus a second muffler could in fact increase drag. Try looking from the front of the bike backwards, with your eye aligned with the most outside edge of the fairings. Can you see the can? If not, that would mean it does not increase the effective frontal area of the bike. If you can see the can, any number of square inches it sticks out would determine how much it restricts airflow.

At extremely high speeds the flow around the bike contributes to drag. It is possible on this bike that a symmetric flow of two mufflers creates a more beneficial, uniform flow. But I wonder if anyone would know this.

Again, consider all this if you are doing extremely high speeds. Anything less, forget all of this.

The weight savings and easy access to the chain makes single-sided exhausts superior in my opinion.

Why do many ppl put the handle on the cowl ?

The pillion handle? It has a cool look to it and kind of finishes off the look of the rear of the bike. That is all personal opinion though. What do you think?

 

[sixpack577]

The grab bar with the hump on also makes it easy to move the bike when you're not on it.

 

[DING]

I totally agree with you. Single muffler at high speed feels bit unstable compared with dual muffler. I tried 240km/h last week on highway and it feels very different compared with dual muffler. But consider the weight loss and sound benefit, I am fine sacrificing that little bit stableness at high speed.

I do not think anyone can provide a definite answer. I see two things at play and both would merely be a factor at extremely high speeds in my opinion.

Aerodynamic drag is a function of the square area as seen from the front of the bike. Anything that sticks out to the sides generates drag. Thus a second muffler could in fact increase drag. Try looking from the front of the bike backwards, with your eye aligned with the most outside edge of the fairings. Can you see the can? If not, that would mean it does not increase the effective frontal area of the bike. If you can see the can, any number of square inches it sticks out would determine how much it restricts airflow.

At extremely high speeds the flow around the bike contributes to drag. It is possible on this bike that a symmetric flow of two mufflers creates a more beneficial, uniform flow. But I wonder if anyone would know this.

Again, consider all this if you are doing extremely high speeds. Anything less, forget all of this.

The weight savings and easy access to the chain makes single-sided exhausts superior in my opinion.



The pillion handle? It has a cool look to it and kind of finishes off the look of the rear of the bike. That is all personal opinion though. What do you think

 

[DING]

I do not think anyone can provide a definite answer. I see two things at play and both would merely be a factor at extremely high speeds in my opinion.

Aerodynamic drag is a function of the square area as seen from the front of the bike. Anything that sticks out to the sides generates drag. Thus a second muffler could in fact increase drag. Try looking from the front of the bike backwards, with your eye aligned with the most outside edge of the fairings. Can you see the can? If not, that would mean it does not increase the effective frontal area of the bike. If you can see the can, any number of square inches it sticks out would determine how much it restricts airflow.

At extremely high speeds the flow around the bike contributes to drag. It is possible on this bike that a symmetric flow of two mufflers creates a more beneficial, uniform flow. But I wonder if anyone would know this.

Again, consider all this if you are doing extremely high speeds. Anything less, forget all of this.

The weight savings and easy access to the chain makes single-sided exhausts superior in my opinion.



The pillion handle? It has a cool look to it and kind of finishes off the look of the rear of the bike. That is all personal opinion though. What do you think?

Make sense

 

[DING]

The grab bar with the hump on also makes it easy to move the bike when you're not on it.

I see, that’s why everytime when I move back my bike, I have to push the cowl backwards hahahah .

 

[DING]

The grab bar with the hump on also makes it easy to move the bike when you're not on it.

Now I have to figure out how to cut the edge of the cowl in order to fit the handle ..

 

[Bumblebee]

Now I have to figure out how to cut the edge of the cowl in order to fit the handle ..

A few threads on this subject in the search feature..

Cowl / hump cutout | Gen 3 Busa Information

I just realized I haven't seen one pic of anyone who has cutout the new rear cowl / hump for the grab rail. I plan on doing that to mine, so where are the pics? ps Any concerns that the cutout won't be waterproof? It wasn't an issue on the Gen 1's...

www.hayabusa.org

 

[Bumblebee]

I totally agree with you. Single muffler at high speed feels bit unstable compared with dual muffler. I tried 240km/h last week on highway and it feels very different compared with dual muffler. But consider the weight loss and sound benefit, I am fine sacrificing that little bit stableness at high speed.

All in your head unfortunately...

A single exhaust won't affect the aerodynamic profile of the bike and it certainly won't destabilize it at speed (any speed). Many (and I mean many) here have had their bikes well over 240km/hr with a single full exhaust with zero issues whatsoever.

Aftermarket single exhaust save a lot of weight and might add a bit more power along with other modifications-it doesn't add much on it's own....maybe 10hp on a good day (maybe).

 

[DING]

All in your head unfortunately...

A single exhaust won't affect the aerodynamic profile of the bike and it certainly won't destabilize it at speed (any speed). Many (and I mean many) here have had their bikes well over 240km/hr with a single full exhaust with zero issues whatsoever.

Aftermarket single exhaust save a lot of weight and might add a bit more power along with other modifications-it doesn't add much on it's own....maybe 10hp on a good day (maybe).

Maybe I felt different at high speed due to huge weight lost hahaha.... I really enjoyed the sound of a single exhaust full system's sound, especially with u shift every gear

 

[DING]

A few threads on this subject in the search feature..

Cowl / hump cutout | Gen 3 Busa Information

I just realized I haven't seen one pic of anyone who has cutout the new rear cowl / hump for the grab rail. I plan on doing that to mine, so where are the pics? ps Any concerns that the cutout won't be waterproof? It wasn't an issue on the Gen 1's...

www.hayabusa.org

thanks a lot for the tip

 

[SS4Luck]

I can barely feel the influence of my aerodisc in a cross wing the change in exhaust was just in your head/road conditions.


For a swingarm give evil Swingarms a call, get yourself an 2-6 and never look back.

 

[Berlin Germany]

Hi, everyone ! Stock exhaust is way too heavy. So I recently got a new Akapovic full system single slipon.
That thing sounds so nice. But I am still a big fan of duo slipons.
So here is the question : are two slipons better than one ? from aerodynamic aspects.

And here are some additional questions
1. Why do many ppl put the handle on the cowl ?
2. What swingarms u guys are using rightnow ? My desired extended length is like 3-4 inches.

Thanks everyone.

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View attachment 1673668

hi hong kong

a good friend of mine did a test on a testbench with his gen3 and the akrapovic (full) exhaust
and the performance was only about 2 hp more in the highest rpm ranges at a material prize of ca. 2500 € here in germany !

pretty much useless, because who constantly rides their bike between 9000-11000 rpm?almost nobody - I suppose.

what then really brought about a significant change in the performance development,
was a rewrite / change of the ecu map . costs - ca. 1000€

especially in the range between 3000 - 7000 rpm, the increase in torque was really significant - I'm talking about 50 Nm more than standard - I have the new performance diagram including the initial measurement as a PDF. is therefore provable.

so save ur money if u don´t wanna change only the optics .