What is a 12min tune?

GPMAZ- Cooler engine at richer a/f ratios is only a side benefit to me, the main reason I tuned for around 13.5 to 1 is for more power. 14.57 to 1 is for emission purposes. The reason you went lean in the higher ranges is that the engine has no way to measure the amount of air entering the engine. If you made intake or exhaust changes more air is going to enter the engine because the intake and exhaust tracts are less restrictive. Therefore you need more fuel. And because it is in an open loop range, there are no trims to correct it to 14.57.

It may not be as noticeable on the Touring models, but on my Classic, until I got a full on dyno tune the throttle was jerky in the mid ranges and small throttle openings. I could also feel a surge more than likely caused by a lean condition.

Doing a PCIII dyno tune I only picked up 6 hp over one of Wayne's canned tunes, but the bike was so much better to ride because of the smooth throttle.
 
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I see references to the 12min tune but I don't know what it is. Are you talking about removing the secondaries or is there more to it than that?
The real idea of the 12 minute tune is to test your ability to stand patiently by the FBG while resisting the urge and reaching over and give her a quick blip of the throttle, just to hear the rumble of those three huge cylinders as it echos through the country side.
The real idea is to give that obnoxious Hardley rider to get 12 minutes down the road, to avoid the embarrassing sight of your tail light as it disappears down the road ahead of him.
The real idea of the 12 minute tune is to test the neighbors who are sure you have died in your garage because they never heard your bike run that long without the gentle roar as you Rocket down the road.
The real idea of the 12 minute tune is put enormous amounts of fuel through the beast with absolutely no visible damage to the Metzler.
The real idea of the 12 minute tune is to mess with your mind, now you have to find something to do for 12 minutes. The minutes pass like hours. Ouch it to hot to polish chrome, can't check the oil while it's running, ouch again that bottom muffler will take the hair off your arm trying to check the air pressure in the rear tire.
The real idea of the 12 minute tune is to allow enough time for a quick beer, that doesn't work time enough for two-- maybe more.
The real idea behind the 12 minute tune is to burn off some of that old $4.00 gas so you can buy some of that cheap $2.00 stuff
The real idea of the 12 minute tune is if you really made it through the 12 minute tune you will imagine that your trusty steed will now outperform your wildest imagination, lord knows you couldn't do this over again. It just feels good to get back on knowing your trusty steed just "Fixed Itself":D
 
The real idea of the 12 minute tune is to test your ability to stand patiently by the FBG while resisting the urge and reaching over and give her a quick blip of the throttle, just to hear the rumble of those three huge cylinders as it echos through the country side.
The real idea is to give that obnoxious Hardley rider to get 12 minutes down the road, to avoid the embarrassing sight of your tail light as it disappears down the road ahead of him.
The real idea of the 12 minute tune is to test the neighbors who are sure you have died in your garage because they never heard your bike run that long without the gentle roar as you Rocket down the road.
The real idea of the 12 minute tune is put enormous amounts of fuel through the beast with absolutely no visible damage to the Metzler.
The real idea of the 12 minute tune is to mess with your mind, now you have to find something to do for 12 minutes. The minutes pass like hours. Ouch it to hot to polish chrome, can't check the oil while it's running, ouch again that bottom muffler will take the hair off your arm trying to check the air pressure in the rear tire.
The real idea of the 12 minute tune is to allow enough time for a quick beer, that doesn't work time enough for two-- maybe more.
The real idea behind the 12 minute tune is to burn off some of that old $4.00 gas so you can buy some of that cheap $2.00 stuff
The real idea of the 12 minute tune is if you really made it through the 12 minute tune you will imagine that your trusty steed will now outperform your wildest imagination, lord knows you couldn't do this over again. It just feels good to get back on knowing your trusty steed just "Fixed Itself":D

hail to the almighty rocket ruler of my sunny day, provider of a smile that never ends, envy of my friends all hail the almighty rocket may she never leave my side as I go on my journey I call life, may her oil run smooth as I go through the sweeping curves, may her chrome shine as I pass harleys, may she allow me to rule the roads as she was created to do. can I get a hell yeah
 
Thanks for the patience P'9r, I'm going to look into eliminating the O2 sensor. I know what you mean about small gains being quite noticeable. I also only had minimal gains between dyno runs but the torque curve was much smoother and you could feel the difference.
 
...I hope that helps.
The real idea of the 12 minute tune is to test your ability to stand patiently by the FBG while resisting the urge and reaching over and give her a quick blip of the throttle, just to hear the rumble of those three huge cylinders as it echos through the country side.
The real idea is to give that obnoxious Hardley rider to get 12 minutes down the road, to avoid the embarrassing sight of your tail light as it disappears down the road ahead of him.
The real idea of the 12 minute tune is to test the neighbors who are sure you have died in your garage because they never heard your bike run that long without the gentle roar as you Rocket down the road.
The real idea of the 12 minute tune is put enormous amounts of fuel through the beast with absolutely no visible damage to the Metzler.
The real idea of the 12 minute tune is to mess with your mind, now you have to find something to do for 12 minutes. The minutes pass like hours. Ouch it to hot to polish chrome, can't check the oil while it's running, ouch again that bottom muffler will take the hair off your arm trying to check the air pressure in the rear tire.
The real idea of the 12 minute tune is to allow enough time for a quick beer, that doesn't work time enough for two-- maybe more.
The real idea behind the 12 minute tune is to burn off some of that old $4.00 gas so you can buy some of that cheap $2.00 stuff
The real idea of the 12 minute tune is if you really made it through the 12 minute tune you will imagine that your trusty steed will now outperform your wildest imagination, lord knows you couldn't do this over again. It just feels good to get back on knowing your trusty steed just "Fixed Itself"

hail to the almighty rocket ruler of my sunny day, provider of a smile that never ends, envy of my friends all hail the almighty rocket may she never leave my side as I go on my journey I call life, may her oil run smooth as I go through the sweeping curves, may her chrome shine as I pass harleys, may she allow me to rule the roads as she was created to do. can I get a hell yeah
HELL YEAH! :bch: that's funny! I don't care who you are :roll:But the post started out intellectually so straighten up and wipe that girin off your mug:D Great explaination Pigger. I believe ya cause I don't know better:D
 
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I have noted that a periodic 12 minute tune followed by a Tuneboy download is like an extra pint of blood or a shot of B-12. I just do it cause it works for me.
 
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Did the 12 min tune following the PCIII, t-plate removal and resistor mod ... definately took out the jerkiness present right after the mods. Thanks for the info.
 
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