801 Slip-on / exhaust list

Tom said:
Dean, how loud is the exhaust; and do you ride it with or without additional db-killer?
I do like the CNC-milled end caps of the exhausts very much; the AR-laser engravings not so much.
I'm quite curious about the fittment of the 800NK exhaust; from my research it might fit even better than the Duke 790/890 exhausts; it's nearly identical, but the mounting point to the rear frame seems to be about 4-5cm more backwards.

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Geez it does look closer with the 800nk, does the pipe you’ve ordered have the bracket attached or loose?
There’s no mistaking the exhaust is loud, though now I’m used to it it’s not obnoxiously loud. I rode with the DB killer in for a few days, then decided to take it out to see how it was. I leave for work quite early (before 6am most days) so didn’t want to annoy the neighbours.. I am now in love with it, and honestly every time I ride it I wish the commute was longer, the noise is perfect!! I always loved the 270 angle crank but now this 285 is just heaven. I’ll never go back. I will one day look at the powerplate/air filter/ fuel x lite upgrade, but I’ll never remove the cat - it would then be too loud for me
 
SvartDean said:
Geez it does look closer with the 800nk, does the pipe you’ve ordered have the bracket attached or loose?
There’s no mistaking the exhaust is loud, though now I’m used to it it’s not obnoxiously loud. I rode with the DB killer in for a few days, then decided to take it out to see how it was. I leave for work quite early (before 6am most days) so didn’t want to annoy the neighbours.. I am now in love with it, and honestly every time I ride it I wish the commute was longer, the noise is perfect!! I always loved the 270 angle crank but now this 285 is just heaven. I’ll never go back. I will one day look at the powerplate/air filter/ fuel x lite upgrade, but I’ll never remove the cat - it would then be too loud for me
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I forgot to add - the Ali express exhaust wasn’t a perfect fit, there was a little play which led to a leak. Yesterday I got some high temp gasket silicone and just bogged both ends - mid pipe to the muffler and mid pipe to the cat. It sat overnight to cure and this morning is 100% perfect
 
SvartDean said:
Geez it does look closer with the 800nk, does the pipe you’ve ordered have the bracket attached or loose?
There’s no mistaking the exhaust is loud, though now I’m used to it it’s not obnoxiously loud. I rode with the DB killer in for a few days, then decided to take it out to see how it was. I leave for work quite early (before 6am most days) so didn’t want to annoy the neighbours.. I am now in love with it, and honestly every time I ride it I wish the commute was longer, the noise is perfect!! I always loved the 270 angle crank but now this 285 is just heaven. I’ll never go back. I will one day look at the powerplate/air filter/ fuel x lite upgrade, but I’ll never remove the cat - it would then be too loud for me
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The brackets to attach the exhausts/mufflers to the rearframe aren't loose; one is welded to the exhaust and one is attached with rivets: but with a custom made bracket or a custom made hanger both should work.
I would like to give the big muffler a try; either with the separate mid pipe or attached to the mid pipe of the 800NK exhaust; from the pics I do like the higher angle of the 800NK exhaust, but the diameter of the pipe is bigger and the muffler might need to be welded to the pipe. I will see what is possible when they arrive.

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yonsson said:
Isn’t Austin racing a US brand? Kinda sketchy if Ali express sells fake stuff?
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@yonsson From what I know AR is a UK brand; and welcome to the real world... 🤷‍♂️
But I would also prefer the muffler without the AR logo.
 
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SvartDean said:
Only sketchy stuff going on here @yonsson 🤣 admittedly I was pretty impressed with my $50 exhaust. Whatever name it’s got printed on the side of it. Yes @Tom mine was also a different diameter and had an adapter.
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@SvartDean out of curiosity; why did you order the separated version of the exhaust and not the welded version?
 
As I wrote in the past, I took out the dbkiller out of the Arrow exhaust. Sound was better, but I had some doubts, that the bike lost some power. On the end the sound was "too much", so I drilled higher diameter of the holes in the killer (14mm instead of original 12mm and add 3 more holes).

I still had doubts about the power. So I ordered new db killer.

Installed yesterday. Sooo ... I lost some of the "bass" sound, but I am ok with that. BUT! The bikes revs MUCH faster and has "boost" above 8000rpms. I have to confirm, that these engines really need some counterpressure and are running worse with free flow exhaust. The difference is really noticeable.

I also struggled with too much aerodynamic noise in the helmet. Ha, it was not the wind, it was strange frequency from the exhaust. I was really surprised.

PS: power was profesionally measured by my dyno-ass :ROFLMAO:
 
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Here from a magazin a comparison of several different slip on Duke 790 exhausts.
The best performance was with the stock exhaust; but with the aftermarket exhausts (all of them with quite voluminous
mufflers) the bike lost just 1hp to a bit more than 2hp.

10.jpg
 
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animals21 said:
As I wrote in the past, I took out the dbkiller out of the Arrow exhaust. Sound was better, but I had some doubts, that the bike lost some power. On the end the sound was "too much", so I drilled higher diameter of the holes in the killer (14mm instead of original 12mm and add 3 more holes).

I still had doubts about the power. So I ordered new db killer.

Installed yesterday. Sooo ... I lost some of the "bass" sound, but I am ok with that. BUT! The bikes revs MUCH faster and has "boost" above 8000rpms. I have to confirm, that these engines really need some counterpressure and are running worse with free flow exhaust. The difference is really noticeable.

I also struggled with too much aerodynamic noise. Ha, it was not the wind, it was strange frequency from the exhaust. I was really surprised.

PS: power was profesionally measured by my dyno-ass :ROFLMAO:
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I 100% believe this would be the case, I was possibly hoping to gain a few horses back with the fuel x, ktm power plate and K&N air filter. Maybe @yonsson can tell me whether it’s been successful for him?
 
SvartDean said:
I 100% believe this would be the case, I was possibly hoping to gain a few horses back with the fuel x, ktm power plate and K&N air filter. Maybe @yonsson can tell me whether it’s been successful for him?
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I love the sound.. it sounds better everyday too honestly 😀 I’m still restricted with my rev limiter to 6500 anyways until 1000km’s so I’ll see what happens then
 
I am not able to read it so small in German language, so I don´t know, if the test was done with "dbkiller out" also. My experience is with Arrow exhaust - killer in vs killer out and the difference is noticeable.

Normally with louder exhaust you at least think it is more powerful (more sound, more HP :LOL:), but in this case you can feel lower power even with higher decibels.

And yes, all this should be solved by mapping. But there is still no mapping from KTM/HSQ. If there will be one for decat, I will be happy. But do not expect that.
 
SvartDean said:
I had the idea of possibly just swapping out the actual muffler, and leaving the mid pipe. I didn’t account for the poor fitment though
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Yesterday the first boxes with some of the ordered parts arrived; also the mid pipe; it looks quite OK.
Is yours different?

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animals21 said:
I am not able to read it so small in German language, so I don´t know, if the test was done with "dbkiller out" also. My experience is with Arrow exhaust - killer in vs killer out and the difference is noticeable.

Normally with louder exhaust you at least think it is more powerful (more sound, more HP :LOL:), but in this case you can feel lower power even with higher decibels.

And yes, all this should be solved by mapping. But there is still no mapping from KTM/HSQ. If there will be one for decat, I will be happy. But do not expect that.
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The test is with "db-killer in".
 
Tom said:
I will give it a try one of the next days.
Did you exchange the manifold gasket or kept the old one?
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I kept the old one, though when I fixed the exhaust leak with some gasket silicone I ran a few rings around the manifold also before I clamped it shut.
 
SvartDean said:
I 100% believe this would be the case, I was possibly hoping to gain a few horses back with the fuel x, ktm power plate and K&N air filter. Maybe @yonsson can tell me whether it’s been successful for him?
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I don’t know about the peak horse power, but with K&N-filter, slipon and FuelX Pro+ my bike runs very smoothly, also on low revs which wasn’t the case before I installed the FuelX. Since it runs much smoother on low & mid revs there should absolutely be some power gain there.

Regarding peak power over 8k rpm and my short exhaust: I have no idea if there’s a difference compared to the original muffler. I would have loved to see bench results. I have a db-killer in the midpipe but took out the db-killer in the endcan.
 
SvartDean said:
I 100% believe this would be the case, I was possibly hoping to gain a few horses back with the fuel x, ktm power plate and K&N air filter. Maybe @yonsson can tell me whether it’s been successful for him?
Click to expand...
Whats a KTM power plate? A guess would be the lid to the air filter but with slits?

Is there a noticeable difference using the K&N-filter? To the best of my knowledge, less resistance means more airflow which in turn means less filtration, which is of course the trade off.
 
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