best exhaust system
Tom
New Member
I agree, it would be great if I could find definitive proof on which exhaust performs best on my 2017. I think the problem with this would be all of the variables that can impact the readings for such minuscule gains. Having the same AFR for each of the different exhausts, and the same environmental variables for each of the dyno runs would be tedious.
This is where dyno postings are valuable in the "Put up or Shut Up" category. 
There are three main options:
1) Akrapovic
2) Arrow (combined with the Tyga Header for compatibility with the 2017)
3) Tyga w/Maggot cans
The Tyga exhaust combined with the Tyga Header has shown to make the same power as the Akrapovic system. The Akrapovic system is pretty much the yardstick to match. to my knowledge, no one has managed to best it... which makes sense considering it's the system they put on the cup bike as well.
Part of the problem with "best" is also that "best" is subjective. Where do you want to make your power, as you can move the peak HP up and down in the rev limit and get a change in torque. For pure racing, where (pretty much) all you are concerned about is peak HP, then that's where the Akrapovic, Arrow, and Tyga exhausts shine.
For the Tyga vs Yoshi, I have never seen any dyno results with the Yoshi. I know the Tyga system is lighter, and that the cans are made ESPECIALLY for the RC390, so don't protrude so far out past the back of the bike. This is a concern in a crash where the cans are then subject to damage if the bike at some point is pointed backwards... and we ALL know bikes do whatever the **** they wanna do once the rider leaves the seat. LOL
There are also differences based on motor tune, and if you are running a complete airbox (to be supersport eligible) or are running with the airbox mod. With a complete airbox, the Tyga header is essential! Paxton has posted dyno results with the Tyga header. The header is also needed if you want to run an exhaust made for a 2015-2016 bike, on a 2017 model which changed the header. With the airbox mod, the header doesn't make as much power, but does still make more power than the stock header with the dent in it to clear the frame.
As Tom points out, actual dyno results are too difficult to compare when they are run on different bikes, with different states of tune (or even valve adjustment, oil used, fuel, altitude, etc) as even the same bike with the same exhaust with the same everything will show one number on one dyno, and another number on a different dyno. Not all dyno's are created equal, and you'll even have differences on the same dyno model from one to the next depending on it's calibration. So the only thing that REALLY counts is back to back to back to back runs. No one has done this. Likely, nobody ever would... there are just too many variables to run as the matrix starts to get REALLY big once you start taking into account valve adjustment, fuel used, air filter, open airbox or airbox mod, etc etc etc etc etc.
What I can say, difinitevely, is that we have not seen anyone best the Akrapovic, and arrow and Tyga match the Akrapovic. So at that point, it comes down to weight and if you want to do an undertail or right side exit. Undertail is the "best" solution for crash protection of the exhaust system. The bodywork protects the right side of the bike pretty well, and if coupled with the sliders on the front and rear and clipons with replacement bars, these bikes crash REALLY well.
So, clear as mud? LOL
There are three main options:
1) Akrapovic
2) Arrow (combined with the Tyga Header for compatibility with the 2017)
3) Tyga w/Maggot cans
The Tyga exhaust combined with the Tyga Header has shown to make the same power as the Akrapovic system. The Akrapovic system is pretty much the yardstick to match. to my knowledge, no one has managed to best it... which makes sense considering it's the system they put on the cup bike as well.
Part of the problem with "best" is also that "best" is subjective. Where do you want to make your power, as you can move the peak HP up and down in the rev limit and get a change in torque. For pure racing, where (pretty much) all you are concerned about is peak HP, then that's where the Akrapovic, Arrow, and Tyga exhausts shine.
For the Tyga vs Yoshi, I have never seen any dyno results with the Yoshi. I know the Tyga system is lighter, and that the cans are made ESPECIALLY for the RC390, so don't protrude so far out past the back of the bike. This is a concern in a crash where the cans are then subject to damage if the bike at some point is pointed backwards... and we ALL know bikes do whatever the **** they wanna do once the rider leaves the seat. LOL
There are also differences based on motor tune, and if you are running a complete airbox (to be supersport eligible) or are running with the airbox mod. With a complete airbox, the Tyga header is essential! Paxton has posted dyno results with the Tyga header. The header is also needed if you want to run an exhaust made for a 2015-2016 bike, on a 2017 model which changed the header. With the airbox mod, the header doesn't make as much power, but does still make more power than the stock header with the dent in it to clear the frame.
As Tom points out, actual dyno results are too difficult to compare when they are run on different bikes, with different states of tune (or even valve adjustment, oil used, fuel, altitude, etc) as even the same bike with the same exhaust with the same everything will show one number on one dyno, and another number on a different dyno. Not all dyno's are created equal, and you'll even have differences on the same dyno model from one to the next depending on it's calibration. So the only thing that REALLY counts is back to back to back to back runs. No one has done this. Likely, nobody ever would... there are just too many variables to run as the matrix starts to get REALLY big once you start taking into account valve adjustment, fuel used, air filter, open airbox or airbox mod, etc etc etc etc etc.
What I can say, difinitevely, is that we have not seen anyone best the Akrapovic, and arrow and Tyga match the Akrapovic. So at that point, it comes down to weight and if you want to do an undertail or right side exit. Undertail is the "best" solution for crash protection of the exhaust system. The bodywork protects the right side of the bike pretty well, and if coupled with the sliders on the front and rear and clipons with replacement bars, these bikes crash REALLY well.
So, clear as mud? LOL
Tom
New Member
The Yoshimura "works" exhaust would be a prime candidate for testing to me. When you have a large corporation claiming the gains they make to the point they start including dyno charts in their advertisements, we really need a layer of 2nd party proof. I love the dual Tyga but the side mounted carbon for Yoshi looks and sounds pretty sweet too.
Tom,
Just a little piece of info. I purchased the side mounted Yosh and yes, it looked good and sounded good. It was also a giant pain in the ass to install, it more or less had about 1/2cm of clearance from the swingarm unless you mounted the thing artifically "low," which would have meant I was dragging it all over the place on the track. It was also surprisingly heavy.
I ended up going with a Competition Werkes High Mount exhaust, and my friend went with the Tyga undertail. The Tyga is definitely the way to go if you can spend the money. Just my $0.02.
Just a little piece of info. I purchased the side mounted Yosh and yes, it looked good and sounded good. It was also a giant pain in the ass to install, it more or less had about 1/2cm of clearance from the swingarm unless you mounted the thing artifically "low," which would have meant I was dragging it all over the place on the track. It was also surprisingly heavy.
I ended up going with a Competition Werkes High Mount exhaust, and my friend went with the Tyga undertail. The Tyga is definitely the way to go if you can spend the money. Just my $0.02.
This is where dyno postings are valuable in the "Put up or Shut Up" category.
There are three main options:
1) Akrapovic
2) Arrow (combined with the Tyga Header for compatibility with the 2017)
3) Tyga w/Maggot cans
The Tyga exhaust combined with the Tyga Header has shown to make the same power as the Akrapovic system. The Akrapovic system is pretty much the yardstick to match. to my knowledge, no one has managed to best it... which makes sense considering it's the system they put on the cup bike as well.
Part of the problem with "best" is also that "best" is subjective. Where do you want to make your power, as you can move the peak HP up and down in the rev limit and get a change in torque. For pure racing, where (pretty much) all you are concerned about is peak HP, then that's where the Akrapovic, Arrow, and Tyga exhausts shine.
For the Tyga vs Yoshi, I have never seen any dyno results with the Yoshi. I know the Tyga system is lighter, and that the cans are made ESPECIALLY for the RC390, so don't protrude so far out past the back of the bike. This is a concern in a crash where the cans are then subject to damage if the bike at some point is pointed backwards... and we ALL know bikes do whatever the **** they wanna do once the rider leaves the seat. LOL
There are also differences based on motor tune, and if you are running a complete airbox (to be supersport eligible) or are running with the airbox mod. With a complete airbox, the Tyga header is essential! Paxton has posted dyno results with the Tyga header. The header is also needed if you want to run an exhaust made for a 2015-2016 bike, on a 2017 model which changed the header. With the airbox mod, the header doesn't make as much power, but does still make more power than the stock header with the dent in it to clear the frame.
As Tom points out, actual dyno results are too difficult to compare when they are run on different bikes, with different states of tune (or even valve adjustment, oil used, fuel, altitude, etc) as even the same bike with the same exhaust with the same everything will show one number on one dyno, and another number on a different dyno. Not all dyno's are created equal, and you'll even have differences on the same dyno model from one to the next depending on it's calibration. So the only thing that REALLY counts is back to back to back to back runs. No one has done this. Likely, nobody ever would... there are just too many variables to run as the matrix starts to get REALLY big once you start taking into account valve adjustment, fuel used, air filter, open airbox or airbox mod, etc etc etc etc etc.
What I can say, difinitevely, is that we have not seen anyone best the Akrapovic, and arrow and Tyga match the Akrapovic. So at that point, it comes down to weight and if you want to do an undertail or right side exit. Undertail is the "best" solution for crash protection of the exhaust system. The bodywork protects the right side of the bike pretty well, and if coupled with the sliders on the front and rear and clipons with replacement bars, these bikes crash REALLY well.
So, clear as mud? LOL
Thank you very much! What is the Arrow model that you are referring to? (I live in Chile and here Arrow is the cheapest option)
The Arrow exhaust is the same side exit exhaust which is a copy of the Akrapovic. That's for the 15-16 model years. For a 17, you would need the Tyga Header to be able to still run a 15-16 exhaust system on a 17+ model year. That's what I meant by for compatibility, because KTM changed the header and mid-pipe in 17 making prior year model slip-on exhausts no longer compatible. That's where the Tyga Header comes in.
Tom
New Member
Thanks antarius,
I like that the canisters on the Tyga exhausts are meant for our bikes, so the lenght and weight are perfect. But the carbon canisters on the Yoshi dual just keep bringing me back to wanting that look over the Tyga. I've also heard the Tyga systems are louder than the Yosh, but I'd assume thats not something you can prove without a decible meter.
I like that the canisters on the Tyga exhausts are meant for our bikes, so the lenght and weight are perfect. But the carbon canisters on the Yoshi dual just keep bringing me back to wanting that look over the Tyga. I've also heard the Tyga systems are louder than the Yosh, but I'd assume thats not something you can prove without a decible meter.
The Tyga oval carbon endcap cans have a Decibel Killer (DBK) in them stock, but it can be removed. With the DBK in the cans are certainly louder than stock, but not greatly so. With the DBK removed they are louder, but still not as loud as the Maggot cans. The Maggot cans are still under DB limits for tracks, but would probably get a raised eyebrow from a LEO. I have on my backburner tasklist to get back to back runs done with a DB Meter, but have yet to actually get it done. On the mule here, I run the carbon oval cans with the DBK in them... as it lives on the street for the most part... when it's not on a dyno for testing.
It depends on your model year. They have two systems:
https://www.arrow.it/es/assembled/1388/KTM-RC-390-2015
Or
https://www.arrow.it/es/assembled/1512/KTM-RC-390-2017
https://www.arrow.it/es/assembled/1388/KTM-RC-390-2015
Or
https://www.arrow.it/es/assembled/1512/KTM-RC-390-2017
Similar threads
