Exhaust

The bike will not run noticeable leaner just because you removed the db-killer, but the Euro 5 and Euro 5+ bikes are very lean tuned in general.
The 97° is the temperature of the coolant, not the temperature inside the engine; it's much higher.
I've read several articles and viewed several videos about the Duke 790/890 exhausts and tuning options (same engine like the 801).
It seems the stock Duke and also 801 mufflers are very good "performers" as the engine "likes" a muffler with some volume and some backpreassure.
With most aftermarket mufflers you'll loose some performance; especially with the very small mufflers.
The difference seems to be quite big; here a dyno graph of a Duke 790 with stock muffler and the Coober LM Ecu; with stock muffler and stock Ecu; with Ixrace muffler and Coober LM Ecu. With the Ixrace the bike lost 10HP and 6NM.
If the goal is to get an engine that doesn't run as lean as the stock engine, both solutions (the Fuel X and the Coober) seems to be fine.
But if you want to get some more (noticeable) HP and NM, you may need a proper custome remapping of your ECU.


801_Coober_Ixrace.jpg
 
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Here also a link to a quite interesting video with some more information.
In the video they are remapping a Duke 790, that stock had a reduced performance (95 hp).

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Hi Tom, thanks.

I know, that inside the motor temperature is much higher. I wanted to point out, that before taking out the killer, I did not ever notice, that the bike will not be able to cool down itself even there were much higher temperatures outside. That is the reason why I think, the bike runs much leaner now.

My goal is to not loose any power, probably get better torque curve (more in low and middle) and get better sound.

Thanks for the graph, interesting.
 
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animals21 said:
Hi Tom, thanks.

I know, that inside the motor temperature is much higher. I wanted to point out, that before taking out the killer, I did not ever notice, that the bike will not be able to cool down itself even there were much higher temperatures outside. That is the reason why I think, the bike runs much leaner now.

My goal is to not loose any power, probably get better torque curve (more in low and middle) and get better sound.

Thanks for the graph, interesting.
Click to expand...
I added K&N filter and the FuelX, should at least make the mix a little better.

I didn’t notice any power loss at all from the IXrace. A little curious to get the bike benched.
 
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Tom said:
The bike doesn't run noticeable leaner just because you removed the db-killer, but the Euro 5 and Euro 5+ bikes are very lean tuned in general.
The 97° is the temperature of the coolant, not the temperature inside the engine; it's much higher.
I've read several articles and viewed several videos about the Duke 790/890 exhausts and tuning options (same engine like the 801).
It seems the stock Duke and also 801 mufflers are very good "performers" as the engine "likes" a muffler with some volume and some backpreassure.
With most aftermarket mufflers you'll loose some performance; especially with the very small mufflers.
The difference seems to be quite big; here a dyno graph of a Duke 790 with stock muffler and the Coober LM Ecu; with stock muffler and stock Ecu; with Ixrace muffler and Coober LM Ecu. With the Ixrace the bike lost 10HP and 6NM.
If the goal is to get an engine that doesn't run as lean as the stock engine, both solutions (the Fuel X and the Coober) seems to be fine.
But if you want to get some more (noticeable) HP and NM, you may need a proper custome remapping of your ECU.


View attachment 7349
Click to expand...
I tried to get more info from the source regarding this but I couldn’t find out how many db-killers that were used in the IXrace exhaust. It comes with two and both can be removed. Decreased back pressure could negatively impact the power.
 
I took a look on all the videos with Duke 790.

To full understand all of the things, I am missing graphs without their mapping. I can see, that best result is only decat, original muffler and map. We have to NOT consider the high-end power, because 790 Duke is detuned to 70kW there and this is not valid for our Pilens. So we have to look on low- and mid-

Their end-can was a short one, this can also be a problem and reason, why Arrow or Akrap are long tubes.

Pity, they did not showed us combination of de-cat + original muffler. That would help me a lot.
 
animals21 said:
I took a look on all the videos with Duke 790.

To full understand all of the things, I am missing graphs without their mapping. I can see, that best result is only decat, original muffler and map. We have to NOT consider the high-end power, because 790 Duke is detuned to 70kW there and this is not valid for our Pilens. So we have to look on low- and mid-

Their end-can was a short one, this can also be a problem and reason, why Arrow or Akrap are long tubes.

Pity, they did not showed us combination of de-cat + original muffler. That would help me a lot.
Click to expand...
The low hp version of the 790 engine doesn’t have the same internals as ours. It’s not just the map that’s different.

Our 801 also has a different ECU (Bosch) which isn’t as easily tuned as the 790L ECU.
 
yonsson said:
The low hp version of the 790 engine doesn’t have the same internals as ours. It’s not just the map that’s different.

Our 801 also has a different ECU (Bosch) which isn’t as easily tuned as the 790L ECU.
Click to expand...

From what I've read it's just the software that is different between the 105hp Duke 790 and the 95hp Duke 790 L (that can be reduced to A2 conform 48hp); the internals are identical; same part numbers; some "Duke-790-people" already researched it.
 
Tom said:
From what I've read it's just the software that is different between the 105hp Duke 790 and the 95hp Duke 790 L (that can be reduced to A2 conform 48hp); the internals are identical; same part numbers; some "Duke-790-people" already researched it.
Click to expand...
I’m smart enough to to contradict you but I did a lot of research before buying the 801 and my conclusion was the 790 and the 790L are made in different factories and have different internals. It’s not possible to remake the L-motor into the full power version. Different cams and other stuff. I don’t have time to look it up right now though.

If I remember correctly, the airbox is different too.
 
Just did a quick comparison on partnumbers
Camshafts, pistons, conrods, airbox and crankshaft are all the same partnumbers on the 2024 Duke and Duke L.
According to a Dutch dealers website.
 
nampus said:
Just did a quick comparison on partnumbers
Camshafts, pistons, conrods, airbox and crankshaft are all the same partnumbers on the 2024 Duke and Duke L.
According to a Dutch dealers website.
Click to expand...

Out of curiosity I just did the same "Duke 790" and "801"; camshafts, pistons, conrods, airbox and crankshaft; again same part numbers.
I also checked the 790 and 790L ECUs; both also same partnumber 63541031100; made by Bosch.
 
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When I bought my Vitpilen my local ish dealer had an ´L´ model in stock but could not get the 105 bhp version. I asked if it was possible to alter/upgrade the 95bhp ´L´ to the full power and was told it was not possible. The dealer checked with Husqvarna themselves. I had to buy one 300km away.
 
Dhd12 said:
When I bought my Vitpilen my local ish dealer had an ´L´ model in stock but could not get the 105 bhp version. I asked if it was possible to alter/upgrade the 95bhp ´L´ to the full power and was told it was not possible. The dealer checked with Husqvarna themselves. I had to buy one 300km away.
Click to expand...

From what I've read, the reason is the EU classification of vehicle types.
Only the official A2 homologated (95hp) L version is allowed to be reduced to 48hp.
The other way round it's not allowed to make a completely opened up 105hp A-version from a reduced 95hp A2-version.
Technically it would be possible, but politically it's not wanted/not allowed.
 
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OK, but back to the basic question ;o)

Looks like, that with killer out, I had lost some power. With modified killer (more holes and drilled bigger) almost same situation. There was an info in the video, that these motors like some back pressure and run better with buffle in.

OK. Seems to me, that without a dyno and mapping is best solution buffle in :-( I dont want to waste a lot of money for decat and coober and on the end find out, that is it - at the best - the same or even worse.

There is really nobody who made those mods with some dyno test? Because in the video it is always about their mapping ...
 
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With the shortened db-killer/baffle in the stock muffler I didn't notice any loss of power (just some more grin in my face); but maybe your butt-dyno is more sensitive than mine... ;)
 
My butt-dyno didn't notice a difference with an IXIL Race slip-on but just like Tom my grin speaks for itself.
 
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