Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

AFR tips for my STrumpet!

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by Mr Messy, Jul 13, 2012.

  1. Hey all.
    Finally got my bike finished except for playing with AFR's in my powercommander/autotune combination, and maybe giving it a wash and polish for photos :D.

    2009 Triumph Sprint ST 1050, with a K&N filter and a baffleless staintune system... (and a sheetload of at this time irrelevant mods!).

    Any tips for AFR settings with that sort of a combo?? Or am i just going to have to experiment? I am planning on starting out with AFR of 13:1 and fiddling from there. I expect to be able to run a little richer with a freer flowing system, reasonable assumption or no?
  2. Eh, should add that yes im aware Autotune does all that, but it starts from a baseline, and after any tips to help optimise the baseline ;).
  3. Sorry, haven't played with FI... Put some flatslide carbs on it :)
  4. The optimum baseline afr comes from a DYNO. The autotune will then try to make trims to fuelling to keep the afr in line with that baseline. It's designed for a pretty narrow operating range when cruising in a particular rev range. It's not a super dynamic broad spectrum thing. You'll be chasing your tail if you keep looking at it after a road ride. Without the initial dyno you are blindly guessing what afr is best for YOUR bike at that rpm and throttle increment in that atmospheric environment, good luck.
  5. Thats what i thought Rich, and why i asked the guys to do a dyno run on it for me but they harped on about how the autotune handles that.
    Ill have another word with them.
  6. Been to powercommander's web site??
    Is there a map to suit your basic setup that you can use as a starting point ?
  7. Yeah they have a stock map. Im comparing that to the TOR map that i have in the ECU now just to see the variances.
  8. Sorry mate, the only way to use it properly is to get it dynoed. Autotune aims for a target afr, and the optimum afr comes from a dyno. Maps from the us are guesswork at best. Not exactly based on relative air density. Do it, then save the file then work from that with the autotune thereafter. You've come this far, don't skimp a few hunge now. If the ship doesnt agree then time to find a new shop, that's just how the device work, it is what it is ya know.
  9. Roger that :p.
    Is what i thought and couldnt understand the bs they were spinning me ;).

    Weekend of course, will call them monday...
  10. Shes dyno'ed now :). Waiting for them to email me graphs, but the manufacturer spec of 125hp is at the crank, originally stock tested as 114 rear wheel horsies.
    Once the baseline was evened out a little for the exhaust system, shes now up on 124rwhp... zzzzooooooommmm :p.
    Ill be posting up a 'new bike' thread soon due to how many mods i made on the bike since starting on it 9 months ago.

    Edit: 124 not 114...
  11. Basic idea: get the fuel map close to 12.8:1 under load, close to 14.7:1 with less load and possibly even a bit leaner under cruise/decel. The shape of the original map should give you an idea. I guess ideally with a power commander you're just aiming to restore the AFR's back to somewhere near where they were at the equivalent load/rpm points on a non-modified engine, so if you have baseline dyno AFR figures from a non modified engine it might make it a bit easier.

    Also, it's pretty important get the map looking nice and smooth.

    If you're aiming to do more than just take the exhaust/intake mods into account AFR-wise, then you'll probably want to start tweaking the ignition advance maps, but that can get a fair bit more complicated.

    Did you get full dyno run results before and after the tune?