I recently changed the stock exhausts on my Ultra Classic with a 103 motor to Cobra true dual exhaust. Do I need to retune the motor?

 

I would say yes. It’s not like you just changed to a different 2-1-2 header and/or mufflers. You now have completely separate exhaust for both cylinders. It may run ok but I can’t believe your current tune is close to optimal.

 

Why did you go true duals? You spent money to decease your power. You better get it tuned to at least get it back to the performance you had before.

 

Now you opened up your exhaust cat gone, if you did not use a free flow A/C do that too. Than for performance, a tuner and dyno tune. But if your happy don't do nothing

 

Scout, he didn't pay money to decrease his performance, he paid money to put a different looking and sounding exhaust system on his bike that HE WANTS. Some of you guys really come down hard on others because they don't go the all out 2-1 mega hp and torque promising pipes. Did anyone give sarcastic remarks when you put on the Black-ops Carbon-fiber X-2000 coffee cup holder ------ with kung-fu grip on your bike? Im being sarcastic here but really, telling him that was being bit of a dick don't you think?

randy

 

Scout, thanks for the reply. I did notice a slight reduction in performance. Went to true duals because the rear exhaust cracked right at the cylinder. I'll get it retuned.

 

I don't know about true duals but just swapping mufflers out does not require a remap. As long as the stock air filter is used it is still only sucking in the same amount of air. Once you change to a high flow air filter it changes the air to fuel ratio, then you would need to tune/remap it

 

When you get a chance, I'd like to see a video, with sound, of the new setup.

 

Also curious about the sound of those as they look great and can be found for a great price.

BTW.....love the 'Why did you choose to lose power and performance by installing those True Duals?' crowd!!! If you're buying a Harley for great performance, power, speed and torque you might want to rethink your decision.....and your life.

 

On the subject of losing power - or not - I have had my bike dyno-tuned with TDs and then again some time later with a Supertrapp 2-into-1. Both systems were tuned by the same shop and operator. Headline numbers for both systems were very close, not enough difference to argue over. The differences were in low/mid range torque, with the TDs having a significant dip in torque when compared with the Supertrapp. The remarkable diffference is how much smoother running the engine is with the SuperTrapp - well worth making the change. Sound is of no interest to me, but riding experience and performance certainly are. SuperMeg wins hands down!