hi everyone,

i have a 2016 fxdb with a TBR comp s exhaust and andrews 57h cams. since installing the cams the bike has some ride-ability issues between idle and 2500rpm.

this bike is a daily for me and in peak hour traffic i often have to crawl along at 40km/h (25mph) in 2nd gear. prior to cams this was no issue at all, but now the bike starts to convulse and surge in that rev range. the tuner knows the issue is there and he believes it's exhaust related. TBR suggested its a bad marry of parts. the bike great everywhere except this rpm range.

the bike has been dyno tuned using powervision, and almost every part/sensor/adjuster has been checked and cleaned in the hopes of resolving this.

i know that both the 57h's and the TBR exhaust are very popular choices, but is there anyone using both and how does the bike ride/respond etc.?

 

Hi from the UK and welcome to HDF. With such a wide variety of parts available to us Harley owners it is all too easy to get a "bad marry of parts". When making mods it is wise to consult an experienced tuning shop first, to get a proven combination of components. Quite frankly the muffler of the Comp S looks too short to my eye. What does your tuner suggest as a way ahead?

 

That RPM/load area may be susceptible to reversion- put it back on the dyno, set RPM/MPH to duplicate the conditions, and then apply load until it starts giving you the same grief on the dyno you were having on the street. Once the exact spot is found, go into the map @ that spot, and look at timing and VE F&R to see if anything stands out. If so, adjust accordingly. If not, try reducing timing at that one spot, or maybe going open loop in that one area, or both, until it smooths out. It's gonna take some time/evaluation , but sometimes combos need more attention to make acceptable. Reversion is a pain, because the 02 sensors don't know if the measured residue 02 ( reported AFR) in the pipe is going out or coming in (( and autotune can't fix it)).
HTH

 

Well stated Robin.
This is but just one issue with “autotune” systems. The more mods done to the engine the less reliable autotune systems work.
I see at least 1 PV autotune bike that runs like crap until tuned and then with closed loop used where it works and avoided where it doesn’t.
Knowledge and experience = Smooth, responsive Power!
Bob

 

Has your tuner checked or graphed the maps sensor data? You might want to take a look at the data there. The winpv software allows you to make corrections if your map signal is off of what it shoud be,,,MAP normalization i think they call it.
M

 

Same problem I had. I tried different IVO/IVC settings to the canned map from Dynojet, and changed the CDE made it much better (for me anyway) ...I would have hoped your dyno tuner might have tried that.

Is your tuner helping you get to the bottom of it

 

Sounds like you’ve been charged for a dyno tune but didn’t get what you paid for?
A proper dyno tune will present a smooth and responsive bike without rideability issues.
Quite to the contrary, rideability will be superior with a proper tune, not the other way ‘round.
Bob