Best sounding exhaust

939 owner here.

Bought a Zard Penta straight from the manufacturer in Italy. Deleted the cat and also saved about 10 pounds (Titanium/Carbon version)

Sounded glorious with DB killers in- more brap-tastic and snarl-ier. BUT..... w/o a tune, made the bike run like crap. LOTS of popping during decel (no matter gear/rpm range) and the bike stumbled at 3-3500 RPM (where it didn't before). Eventually went back to stock while i research tuning options.

Long story short - you might want to factor in the cost of a tune if you consider a non-termi pipe that deletes the cat.

I have had a CRT and Akrapovic exhaust installed on mine and now back to stock.
And I have to say that the stock is pretty damn good. The Akra would be the pick of the bunch, but to be honest cost versus difference in sound is minimal.
The CRT was stupidly loud to the extent it ruined the natural sound of the bike IMO.

I've ordered a GPR slip on for my 939, it's still yet to arrive. The dealer told me today that fitting a slip on may cause the fault light to come on due to the O2 sensors detecting a leaner engine. How could just a slip on do that?

PaulT said:

I've ordered a GPR slip on for my 939, it's still yet to arrive. The dealer told me today that fitting a slip on may cause the fault light to come on due to the O2 sensors detecting a leaner engine. How could just a slip on do that?

Click to expand...

could be, but in 99.9% will not be

mentalist said:

GPR on mine, sounds great and not offensive like the SC project.
Good quality too.

Click to expand...

Do you think the GPR is comparable in quality to the Arrows and the other less expensive slip-ons?

I put the full Termi on my 939. Left the baffle in and it is not much louder than stock. Deeper tone however. What I really like is how it smoothed the throttle out. Not so jerky on/off feel. Also, my seat of the pants dyno feels some real power gain. I have to be careful when accelerating in low gears as the front end really wants to come up.