Dyno torque dip

  • Quinja
    Quinja
    5 years ago
    Hey everyone,
    Newbie here to dyno charts. Just got a SE204 cam put in my 13 Softail Slim and dynoed. Can someone please explain if the torque dip in the attached pic is normal? The bike rides like a beast and I can’t ‘feel’ the dip when riding. 

    Cheers


  • Grease Monkey
    Grease Monkey
    5 years ago
    It's your pipes mate, if you can't feel it just ride and enjoy, here is one I tuned, 103, 204's and a weird pipe. That's only the horsepower curve but you can't feel it either.

  • steelo
    steelo
    5 years ago
    Good on you for helping out gm 
  • Ratbob
    Ratbob
    5 years ago
    Hi Quinja if you want to understand what’s going on look up 
    Harley-Performance.com
    Down the home page there’s tab 
    Harley Exhaust Comparison
    Gives a basic explanation of pipe characteristics.
  • fatbat
    fatbat
    5 years ago
    Here’s another member’s se204 with 103 dyno’d. I’m pretty sure Baloff is happy with his. Had a decatted oem 2-1-2 exhaust with aftermarket mufflers. 

    And here’s a dyno graph of my old 103 with se204 cams. Had a freedom stepped 2-1 exhaust which I later swapped out for a supertrapp supermeg. My tune had din correction and some weather/atmospheric issues with the dyno calibration. My torque graph fell away a bit. 


    There are many variables among the charts - peak numbers are all similar. Of note you get a good idea by the shape of the charts re what to expect. All three run different exhausts and yours is probably contributing to the early part of the shape on your chart being lower and dipped in the torque graph whereas the other two don’t although mine fell away more later on. As long as you’re happy just enjoy it. 

  • Quinja
    Quinja
    5 years ago
    Hey guys,
    Thanks for the info! I love the sound of my V&H short shots, and since I can't feel that dip I won't be changing them. Was just curious what the cause was. The % increase in on the bike with OEM pipes is impressive. Good bang for your buck there.
  • Baloffski
    Baloffski
    5 years ago
    Well you are a "master"
     fatbat, I just scanned my 103 with 203 cams for Quinja just about to post saw Neville Lush's  Dyno work  and thought.
    "shit how did that get on post, must be blue tooth or am sleep deprived or still pissed."
    Thanks mate, as is good for Qman to sus info on tune for his ride.
    Yours came out straighter than mine..
    My Glide came with Vance and Hines Big Shots, which are still on, as I'm fairly happy withem.
    But, if you have dollars experimenting is good fun.