Tuning softail with no O2 sensors with SEPST
#1
08-14-2018, 12:14 PM
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Tuning softail with no O2 sensors with SEPST
Hi guys, i have an 06 fxsti with some short shots and big sucker intake... i know a canned tune is probably fine, but id like to learn a bit of tuning for my own personal interest and to dial in the bike a little closer....
Ive been reading for quite some time about tuning with the SEPST. looking for some more information. i would like to try and give me bike a custom tune... but all i can find is information on auto tuning.
As i understand, you can make your target AFR anything you want... but your VE tables need calibrated or you are not getting any true numbers... how can you calibrate your VE tables if you dont have O2 sensors... does anyone have a write up for tuning a bike manually without o2s in open loop... without a dyno and verifying results without using wideband o2...
im sure its been covered somewhere i just cannot find much on the subject...
Ive been reading for quite some time about tuning with the SEPST. looking for some more information. i would like to try and give me bike a custom tune... but all i can find is information on auto tuning.
As i understand, you can make your target AFR anything you want... but your VE tables need calibrated or you are not getting any true numbers... how can you calibrate your VE tables if you dont have O2 sensors... does anyone have a write up for tuning a bike manually without o2s in open loop... without a dyno and verifying results without using wideband o2...
im sure its been covered somewhere i just cannot find much on the subject...
#2
08-14-2018, 12:37 PM
Stellar HDF Member
It would be great if we could simply purchase a tuner, fire up some software, and tune up your bike.
First, as you mentioned, you must calibrate/recalibrate the VEs to true numbers. This is based on reading the exhaust O2 and altering the VE numbers until the exhaust measurements agree with target AFRs.
Then, and only then, can changes be made to target AFRs and expect results to be correct.
There is no room for guesswork which is why a proper dyno tune is required, not optional, to get to what is targeted.
The newer bikes have o2 sensors which allow for precise exhaust measurements and there are auto-tune routines available to use the o2 sensors to precisely tune to targets but those are not available for the older bikes,without o2 sensors.
That said, even the auto-tune systems have challenges that extensive tuning experience helps to avoid.
Bob
First, as you mentioned, you must calibrate/recalibrate the VEs to true numbers. This is based on reading the exhaust O2 and altering the VE numbers until the exhaust measurements agree with target AFRs.
Then, and only then, can changes be made to target AFRs and expect results to be correct.
There is no room for guesswork which is why a proper dyno tune is required, not optional, to get to what is targeted.
The newer bikes have o2 sensors which allow for precise exhaust measurements and there are auto-tune routines available to use the o2 sensors to precisely tune to targets but those are not available for the older bikes,without o2 sensors.
That said, even the auto-tune systems have challenges that extensive tuning experience helps to avoid.
Bob
Last edited by FLTRI17; 08-14-2018 at 12:38 PM.
#3
08-14-2018, 12:40 PM
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#4
08-14-2018, 12:52 PM
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The catch is you must add wiring and o2s to your bike and that can be accomplished by going to Matertune.net and finding the list of parts and instructions for the upgrade.
Then you will be able to use the “Mastertune V-tune” (auto-tune) to get the VEs recalibrated.
Either take it,to a qualified, experienced tuner or upgrade your bike so you can do it. Then, if you get stuck, take it to a tuner to get dynoed.
Bob
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08-14-2018, 12:56 PM
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#6
08-14-2018, 01:02 PM
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Wow. I thought since they we're making these open loop bikes for so many years, that tuning wasn't such a big deal. Thanks for the information.
So when you take a bike to a Dyno tuner, they sniff the exhaust with their own equipment in order to make the necessary adjustments??
So when you take a bike to a Dyno tuner, they sniff the exhaust with their own equipment in order to make the necessary adjustments??
Bob
PS- Updating your bike to closed loop is by far the best resolve, no matter if you or a tuner does the recalibration.
#7
08-14-2018, 04:17 PM
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#8
08-14-2018, 04:37 PM
if you were interested in using a different product, the Powervision tuner has an availble pro-tune kit which includes a module and 2 windeband sensors. install the sensors it the pipes, wire the module with the can cable to the PV, mount the PV on your bars( many choices for mounting), and ride the bike using the auto tune functios, you can also data log and rebuild all facets of the map in the WinPV software if you feel you can figure that side out. I am using the above stated equipment to tune my moddded 04 ultra clasic, currently over 100 hp, yippee!
m
m
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08-14-2018, 04:39 PM
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#10
08-14-2018, 05:40 PM
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