KTM Duke 390 Forum banner
1 - 6 of 6 Posts

·
Registered
Joined
·
533 Posts
Discussion Starter · #1 ·
very pretty looking thing I've stumbled across, however I don't know much about them. Whats cool is they don't seem to build systems for specific bikes, they build one system with multiple outlet diameters:

38.1 mm
44.5 mm
50.8 mm
63.5 mm

will any of those fit the Duke?

Supertrapp Exhaust 4"
 

·
Registered
Joined
·
179 Posts
I don't really get how exhaust changes the performance of the bike at all. I get that the weight of the exhaust could make a bit of a difference but other than that I don't really get how it would affect performance.

I mainly judge an exhaust based on its exhaust note. Maybe that is naive of me.
 

·
Registered
Joined
·
520 Posts
better flow usually would mean better performance

to an extent

the engine tuning has to recognize this extra flow and take advantage of it by adjusting timing and a/f ratio to compensate or pump more fuel and air into the chambers.
 

·
Registered
Joined
·
264 Posts
better flow usually would mean better performance

to an extent

the engine tuning has to recognize this extra flow and take advantage of it by adjusting timing and a/f ratio to compensate or pump more fuel and air into the chambers.
and a good exhaust using SWR calculations to provide a negative pulse at the exhaust header when the exhaust valve is open (i.e. tuned length). The original D390 is a tuned length but I'm not sure many of the after market ones are (the fast can Dan and I have is definitely not).
 

·
Registered
Joined
·
520 Posts
so all in all

not every exhaust is the same

and slapping on an expensive exhausts without a tune doesnt always get you the best results.
 
1 - 6 of 6 Posts
Top