New Yoshimura Exhaust coming!!!

[Formula390]

Exactly. And they need to do it quick

It is an EXCEPTIONALLY difficult bike to build an exhaust for that doesn't end up killing power. Any "quick" design is going to be loud, and it might end up in the same location... but you will end up paying a power penalty probably in the 3hp realms. My BEST design ONLY lost 0.5hp and that was with the airbox mod and the PCv. The KTM engineers did a REALLY good job of getting that exhaust built as well as they did in the space they had. They got a LOT of extra length in the system by playing a number of tricks in the canister... which is also why it's as heavy as a boat anchor.

 

[MrGrody]

It is an EXCEPTIONALLY difficult bike to build an exhaust for that doesn't end up killing power. Any "quick" design is going to be loud, and it might end up in the same location... but you will end up paying a power penalty probably in the 3hp realms. My BEST design ONLY lost 0.5hp and that was with the airbox mod and the PCv. The KTM engineers did a REALLY good job of getting that exhaust built as well as they did in the space they had. They got a LOT of extra length in the system by playing a number of tricks in the canister... which is also why it's as heavy as a boat anchor.

Well looks like I'll just have a stock exhaust forever lol

 

[Formula390]

Well looks like I'll just have a stock exhaust forever lol

I'm going to get back to the exhaust design. I have a good idea how to deal with the issues I found in my dyno testing to try and get some of that power back... but, it's going to involve a bunch of expanse with building more prototype exhausts and doing more dyno tests. That's expensive. I sunk over $3k into my designs, and it didn't pan out. I need to manufacture some parts that WILL earn some funds first and restore the R&D budget a bit... so I'm going with some safer designs that aren't performance based. The next three products I'm working on are heavy duty case covers, frame sliders, and a steering damper. Once those are done, and I'm into the process of manufacturing them, I'll look at exhaust designs again. Maybe somebody will build something that'll do it before then... based on my testing tho, it's NOT an easy problem to solve!!! That's why everyone is ending up with non-stock location exhausts for aftermarket.

 

[Dean]

Whats the go with the Yoshi exhaust? pics?

 

[KTMGene390]

IMHO, that Yoshimura exhaust is a waste of money as two mufflers under the seat not only puts weight high up in the chassis, but also two canisters are unnecessary for a single 373 cc engine. That exhaust system is almost surely for looks and not performance. It is possible it will make a noticeable power increase with remapping due to the length and volume of the system similar to the Akrapovic exhaust which achieved this with one canister, albeit a long one. As of current the Akrapovic is the only exhaust proven to make a notable power increase and is why I chose it over the others.

 

[micah360]

yeah... I think this exhaust is really ugly. Probably sounds decent though.

 

[Doctor Chocolate]

What's up guys! I am confirming that Yosh is designing two exhausts for the RC. The reason I know this is because they're using my bike for the development. It was sent over to the factory today. Apparently they are going to see if they can get rid of the catalytic converter. I'm not much of a mechanic so i don't know all of the details surrounding that. They will be designing two versions, one for the street and one for racing. Unfortunately I only get one for free so I'll be taking the race version since I'll be using the bike for racing/trackdays. I'll be posting videos along the way of my race bike build so if you guys are interested you can keep up with my progress on my youtube channel YouTube I don't have any vids of my RC up yet but I do have other racing vids. I'll try and keep you guys posted on how things go. Apparently it's going to take 3-5 weeks and the bike just got dropped off today.

 

[Doctor Chocolate]

Looks like my last post was mysteriously deleted but yes Yosh is developing both a race exhaust as well as a street exhaust. I know this because my bike is the bike they are using to develop the exhaust. It was dropped off today. I believe they are going try and find a way to get rid of the catalytic converter and that will hopefully cut down on weight and heat. I will be posting vids of my build on my Youtube channel https://www.youtube.com/user/bigwl3 I will be turning it into a race bike so the exhaust I will get from Yosh will be the race version. Apparently it will take about 3 to 5 weeks before my bike is ready. I will keep you guys posted as things go along.

 

[OldVet]

I hope the street version is tucked away like the stock exhaust.

 

[reenmachine]

Looks like my last post was mysteriously deleted but yes Yosh is developing both a race exhaust as well as a street exhaust. I know this because my bike is the bike they are using to develop the exhaust. It was dropped off today. I believe they are going try and find a way to get rid of the catalytic converter and that will hopefully cut down on weight and heat. I will be posting vids of my build on my Youtube channel https://www.youtube.com/user/bigwl3 I will be turning it into a race bike so the exhaust I will get from Yosh will be the race version. Apparently it will take about 3 to 5 weeks before my bike is ready. I will keep you guys posted as things go along.

Did you give them the pillion peg assemblies? I would think they'd want a 100% stock bike to develop their street exhaust.

 

[Formula390]

I hope the street version is tucked away like the stock exhaust.

Don't hold your breath on that one. LOL

 

[rippedcb]

I wish Yosh or someone would make a exhaust that looks stock but adds a little more sound.

GPR Ghost line..
replaces the original right at its place.. sounds nice too. Plus you won't have a 3' pipe hanging off the side. That's what i'm looking at:
https://www.youtube.com/watch?v=weUSBQ-cFk0

 

[Doctor Chocolate]

"Did you give them the pillion peg assemblies? I would think they'd want a 100% stock bike to develop their street exhaust."

Good point. I had already taken them off. We'll see if they contact me about them. If needed I can drop them off. Other than the passenger pegs and the side view mirrors, everything on the bike is in stock order.

 

[reenmachine]

"Did you give them the pillion peg assemblies? I would think they'd want a 100% stock bike to develop their street exhaust."

Good point. I had already taken them off. We'll see if they contact me about them. If needed I can drop them off. Other than the passenger pegs and the side view mirrors, everything on the bike is in stock order.

Just my opinion, but I'd reach out to them about the pegs if I were you. Depending on how familiar they are with the bike they might not even think of it. I'd hate for them to spend the time and money to develop an exhaust that ends up interfering with stock parts.

 

[ASM]

View attachment 1325


I might have to see it in person, but that's probably more than I'd want to mount on the arse of a bike this small. What's the word that you have on actual availability?

And usually...I try to remove weight from up high....not add it...

 

[Doctor Chocolate]

Just my opinion, but I'd reach out to them about the pegs if I were you. Depending on how familiar they are with the bike they might not even think of it. I'd hate for them to spend the time and money to develop an exhaust that ends up interfering with stock parts.

I reached out and apparently they don't need them because they are planning on doing an under tail exhaust. I really hope the OP was right about the dual under tail because that would be freaking awesome!

 

[YoshTim]

As the Technical Sales and Service Manager at Yoshimura I can definitively clear up some of the questions here... We do have our own RC390 here that we are actively developing many different configurations that we may or may not bring to market. The dual system in the image was a configuration we are considering for Race applications only. However the system shown maybe very close to a production system "wink-wink". The image was released for feedback from interested parties with great feedback so far. Yoshimura will never offer a "Street" system that has a catalyst eliminated. For any other information please contact our sales office in Chino or contact us through our website. Not really sure who you are Doctor Chocolate but we want all to understand that you are speculating and not speaking on our behalf and are not using your bike for development.

 

[A1VW2NV]

As the Technical Sales and Service Manager at Yoshimura I can definitively clear up some of the questions here... We do have our own RC390 here that we are actively developing many different configurations that we may or may not bring to market. The dual system in the image was a configuration we are considering for Race applications only. However the system shown maybe very close to a production system "wink-wink". The image was released for feedback from interested parties with great feedback so far. Yoshimura will never offer a "Street" system that has a catalyst eliminated. For any other information please contact our sales office in Chino or contact us through our website. Not really sure who you are Doctor Chocolate but we want all to understand that you are speculating and not speaking on our behalf and are not using your bike for development.

Hmmmmm....

 

[psych0hans]

As the Technical Sales and Service Manager at Yoshimura I can definitively clear up some of the questions here... We do have our own RC390 here that we are actively developing many different configurations that we may or may not bring to market. The dual system in the image was a configuration we are considering for Race applications only. However the system shown maybe very close to a production system "wink-wink". The image was released for feedback from interested parties with great feedback so far. Yoshimura will never offer a "Street" system that has a catalyst eliminated. For any other information please contact our sales office in Chino or contact us through our website. Not really sure who you are Doctor Chocolate but we want all to understand that you are speculating and not speaking on our behalf and are not using your bike for development.

How about sending one unit to India for "testing purposes" in more tropical conditions

 

[Doctor Chocolate]

As the Technical Sales and Service Manager at Yoshimura I can definitively clear up some of the questions here... We do have our own RC390 here that we are actively developing many different configurations that we may or may not bring to market. The dual system in the image was a configuration we are considering for Race applications only. However the system shown maybe very close to a production system "wink-wink". The image was released for feedback from interested parties with great feedback so far. Yoshimura will never offer a "Street" system that has a catalyst eliminated. For any other information please contact our sales office in Chino or contact us through our website. Not really sure who you are Doctor Chocolate but we want all to understand that you are speculating and not speaking on our behalf and are not using your bike for development.

Well hell, then I need to find out where my bike is. And no I'm not speaking on Yosh's behalf.