2017 Duke 390 Exhaust Mod

23797 Views 20 Replies 11 Participants Last post by Hedgepig, Aug 3, 2018

FASTLANE1000

Discussion Starter · Aug 30, 2017

5

Hey Guys, I don't know if this has been covered yet so here you go:
The baffle in the end cap can easily be removed by simply drilling it out with 1.5" bi-metal hole saw. This easy 5 minute job improves the sound and flow of the exhaust. I was unsure of the design of the muffler so I cut off an inch or so in length with a 7" reciprocating saw that I installed a metal cutting blade on. The body of the muffler is aluminum. I do have a Powertronics tuner I will be installing. With the Stock Cat box in place I do not imagine this setup would cause problems but try at your own discretion. I still need to file down the exposed aluminum edge of the muffler body and apply some black exhaust gasket to reproduce the stock look. I did not re drill and install new rivets since the end cap fits extremely tight as is.
One day I'll get some better pictures of the bike and a youtube video of the exhaust. Sounds Great!

[/url]20170829_165313 by LANE GORDON, on Flickr[/IMG]

[/url]20170829_165353 by LANE GORDON, on Flickr[/IMG]

[/url]20170829_212806 by LANE GORDON, on Flickr[/IMG]

[/url]20170829_212649 by LANE GORDON, on Flickr[/IMG]

[/url]20170829_212715 by LANE GORDON, on Flickr[/IMG]

See less See more

Reactions: 3

1 - 20 of 21 Posts

Senor.classico

· #2 · Aug 30, 2017

It be cool to see a home made custom shorty exhaust! Coming out right underneath the foot break (rear break).

Senor.classico

· #3 · Aug 30, 2017

Cool job though bro!

1jzsupra

· #4 · Aug 31, 2017

Interesting, have you experienced any lean pops doing this?

DuffMan757

· #5 · Aug 31, 2017

Very cool FASTLANE1000! ..i'm also looking into picking up a Powertronic + Quickshifter let us know how everything goes and your thoughts! Thanks

FASTLANE1000

Discussion Starter · #6 · Aug 31, 2017

1jzsupra said:
Interesting, have you experienced any lean pops doing this?

No popping while riding. It has a little when revving in neutral as the rpms drop but nothing alarming. I have the block off plates to remove the secondary air injection. I'll be installing those as well as the PowerTronic tuner this weekend. Thanks for the feedback guys!

Moe

· #7 · Sep 22, 2017

How much louder did this end up being? I'm looking for just a little bump in decibels. Any video yet?
Also did you have to remove the end cap to do this?

FASTLANE1000

Discussion Starter · #8 · Sep 25, 2017

Moe said:
How much louder did this end up being? I'm looking for just a little bump in decibels. Any video yet?
Also did you have to remove the end cap to do this?

Only slightly louder. Sounds great and won't annoy anyone. Probably not much different than installing a slip-on exhaust. I did remove the end cap and cut a little over an inch of length off but in hind site I didn't have to. You can literally hit it with a hole saw while its installed on the bike. Sorry no videos. I'll try to make one tomorrow.

FASTLANE1000

Discussion Starter · #9 · Sep 25, 2017

Here's a YouTube video
https://youtu.be/s3NpPAIUEm4

Moe

· #10 · Sep 27, 2017

Thanks! I think I'll give it a go this weekend.

Reactions: 1

Peter Brown-Whale

· #11 · Oct 10, 2017

I went ahead and tried this. I could not get the bi-metal holesaw to bite in, it pretty much just destroyed the saw. But I chopped 2 inches off the end of the can and managed to get the db killer out from that side. Put back together with black silicone and a few rivets. Really happy with the sound and look of the shorter can.

Greg Knapp

· #12 · May 23, 2018

https://youtu.be/jPlFe4H8IOM

This is the sound of my bike

Modified stock exhaust and running DNA air filter and PowerTronic tuner

Reactions: 1

1jzsupra

· #13 · May 24, 2018

Greg Knapp said:
https://youtu.be/jPlFe4H8IOM

This is the sound of my bike

Modified stock exhaust and running DNA air filter and PowerTronic tuner

sounds good with a stock exhaust.

Reactions: 1

Shalimargrooming

· #14 · Aug 1, 2018

Tried this with 3 different metal hole drill saws and did not work just polished the mtsl no bite at all. Ended up using drills and saw saw metal saws breaking most of everything over an hour so it's def NOT easy. Finally managed to get it done but to me would have been better off spending $600 on akro and taking db killer out easily then this mod. What a nightmare!

Hedgepig

· #15 · Aug 1, 2018 (Edited)

Shalimargrooming said:
Tried this with 3 different metal hole drill saws and did not work just polished the mtsl no bite at all. Ended up using drills and saw saw metal saws breaking most of everything over an hour so it's def NOT easy. Finally managed to get it done but to me would have been better off spending $600 on akro and taking db killer out easily then this mod. What a nightmare!

After reading this thread I did mine it was easy . bought my hole saw from a company that supplies industry not diy and used a slow speed drill as recommended on hole saw packaging job done in less than 10 minutes .>

. The standard pipe is lighter than any of the road going pipes I have in my store of used bits the only can lighter is from a Husqvarna motocrosser also aluminium . I modified a new secondhand pipe off ebay so I can return to stock easily ( 99 pounds inc postage ) .

Jim157

· #16 · Aug 1, 2018

It took me about ten minutes too. I used two hole saws, which I alternated between, and plenty of gt85 for lubrication. It seemed fairly tough going to start with but the baffle came out quite easily in the end.

Ede

· #17 · Aug 2, 2018

It would be great if the people who made this modification report if they also changed the ECU and any issues.

I asked the KTM technician at my 1000km inspection about this modification and he told me other people did it and had problems.
Maybe it's KTM policy to say something like that. That is why it would be great to get info from the community.

Hedgepig

· #18 · Aug 2, 2018

No problems so far not done many miles though . The dealers probably prefer to sell KTM's own after market parts , for me it was 20 pounds for drilling equipment or over 200 pounds for an exhaust very simple math problem .

Ede

· #19 · Aug 3, 2018

Hedgepig said:
No problems so far not done many miles though . The dealers probably prefer to sell KTM's own after market parts , for me it was 20 pounds for drilling equipment or over 200 pounds for an exhaust very simple math problem .

In principle I agree with your math until there is an engine problem and then it's 20 pounds vs. 2000 pounds or something like that...
I think it's annoying that there is so little official information from KTM about this.

Hedgepig

· #20 · Aug 3, 2018

Harley Davidson were fined a substantial amount I think for selling aftermarket tuning aids under their own banner ( screaming eagle ) following on from this I believe manufacturers are running scared of similar action being taken against them . From my experience with new Triumph motorcycles , removing the cat and fitting loud cans the ECU is capable of recognising and compensating for basic changes , add on tuners can improve on this but in many cases have found to be not needed .

Reactions: 1

1 - 20 of 21 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.