If Anyone Says A Dyno Tune Is A Waste of Money…

…don’t be so sure.

A dead stock Harley-Davidson 110 cu in Screamin’ Eagle motor like the one installed in both of our 2013 Road King CVO’s make about 80 hp and 95 ft lbs of torque.

After having our first 2013 Road King CVO dyno’s by David at Harley-Davidson of Atlanta in August I was amazed at the power the bike was making: it was impressive. The bike had been refitted with a Fullsac exhaust system and the ECU was reprogrammed with a calibration map provided by Fullsac which, at least when I made the change, made the bike run much more smoothly and gave it more power.  I say “may” only because it’s hard to say if it was the exhaust system or the map that made the big difference: sound and feel can convince us of things that may or may not be real, and a louder exhaust note with a more aggressive rumble can definitely make a motorcycle feel more powerful than a quite bike with the same power.

Sadly, two years had passed since the Fullsac system was installed with the ECU map and the bike just wasn’t running as well as it had been, i.e., there was a good amount of popping on deceleration, etc.  I attribute a lot of that to the crappy E15 gas we’re force to use. Be that as it may, David decided he would just start his tune from a stock Harley 110″ CVO ECU calibration map so I never saw what the motor’s numbers looked like with the Fullsac pipes + calibration.  However, coming out of the $400 tuning session, it was making 96 hp and 110 in lbs of torque, which is what you’ll find most dyno-tuned 110″ motors with an aftermarket exhaust system will generate.

DSCN1296 (1)

That brings me to our new-to-us 2013 Road King CVO.  At some point the exhaust system had been changed, but I doubt the ECU was remapped so my assumption was, when put back to the stock exhaust system it was, for intents and purposes, a stock 110″ CVO motor. But, it just sounded awful and didn’t run well.  A lot of that may have been because it was trying to run on nearly year-old gas, so who knows.

After installing the Fullsac exhaust system and loading the calibration Fullsac provides to the ECU, there was no question Blue II was running extremely well: very smooth with more power and far better than when it had been running when we bought it. However, it clearly didn’t have that neck-wrenching acceleration Blue I had after David did the dyno tune.  So, there was no question in my mind that Blue II was going to get the dyno tune right off the bat.

I’d kept my friend David’s trailer here at the house so I’d have it to take Blue II down to Harley-Davidson of Atlanta expressly for the dyno-tune.  So, with the Fullsac system installed and the bike finally insured, registered, titled and signed-up for the Extended Service Plan I was ready to make my appointment with Harley.  I dropped the bike off around 10:00am on Tuesday and picked it back up around 5:00pm; wow: what a difference!

As for how the Fullsac calibration mapped out during the baseline vs. after the tune:

  • Horsepower:  Before was 88.02 and After is 94.66 or a 7% increase
  • Ft Lbs Torque: Before was 100.80 and After is 111.12 or almost an 11% increase

The numbers were very close to what Blue I had made with the very same set-up, noting Blue I had about 17,o00 miles on the motor when it was tuned. Blue II has just around 2,500 miles:

  • Horsepower:  Blue I made 96.21 and Blue II is now making 94.66
  • Ft Lbs Torque: Blue I made 100.82 and Blue II is now making 111.12


FWIW, I saw the same ~10% increase in both horsepower and torque when I had our 2011 Wide Glide dyno-tuned back in September of 2011.


The point is, if you’re going to drop money into a motorcycle engine to get an increase in performance you’ll never get your full money’s worth until you have the engine tuned by a really good tuner.  Yes it sucks to shell out $400 for 4/hours of “work” that may only actually take 2 -3 hours of a tech’s time, but it’s been my experience that I get to amortize that $400 each and every time I pull on that throttle and make my sweetie smile because she enjoys hearing and feeling that added-power just as much as I do. That’s a good thing!


About TG

I've been around a bit and done a few things, have a couple kids and a few grandkids. I tend to be curmudgeonly, matter-of-fact and not predisposed to self-serving chit-chat. Thankfully, my wife's as nice as can be otherwise we'd have no friends. My interests are somewhat eclectic, but whose aren't?
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