Wanting to go back to stock pipe.
#11
The stock PC-V is a piggy-back unit and works or over-rides your ECM.. OK?
It can only adjust with the map that it programmed with OK?
However, if you do not have a PC-V and just stock ECM settings then when ever you add free-er flowing exhaust, breathing capabilities to your system your ECM will continue to make adjustments to where it was prior to the now added free-er flowing exhaust there-by producing more heat to make your stock system compensate.. is my understanding of the process-es anyway..
Is this not correct?
It can only adjust with the map that it programmed with OK?
However, if you do not have a PC-V and just stock ECM settings then when ever you add free-er flowing exhaust, breathing capabilities to your system your ECM will continue to make adjustments to where it was prior to the now added free-er flowing exhaust there-by producing more heat to make your stock system compensate.. is my understanding of the process-es anyway..
Is this not correct?
If you used a PC with 02 eliminators that basically tells the ECM to not adjust. Adding the PC on top would continue to send the same value and nothing would change at all.
Conceptually you are correct. The ECM has an algorithm in that receives feedback from the 02 sensor and makes a slight adjustment within a limited range. It is not actually very much at all. The ECM starts with a set value in a table for an RPM/TP range and then the algorithm makes the adjustment to that value based on the feedback it receives from the 02 sensor. The ECM itself does have another table called an adaptive fuel table (which I have never seen exposed) that stores this new value (as an average in the range) for use later (sort of like cache) but it still all goes back to the base value.
So you are not wrong - but the PC in and of itself has no ability to make something better or worse once the tuned configuration is adjusted. The ECM is only going to adjust so much and the PC is going to continue to do its thing. The OP will likely not feel the impact of the change he is considering, however the bike is probably not going to run as well as it does now (if it is tuned) but it would likely not damage the engine. If it were my bike however (i am ****), I would retune it.
#13
You will not need a re-tune. The stage one map keeps you in the EPA Air fuel ratio most of the time anyway. The only thing a stage one tune changes it the VE maps. The ECM will slightly adjust to keep you close to 14.6:1 ratio no matter what pipes you run. The stock pipes are more restrictive but its actually better to run a stage one map with a stock setup. You will get more power better cooling and better torque without killing your MPG. I am currently running this setup with 255 cams and bike runs quiet, strong, cool, and just overall great.
#14
easy to adjust the supertrapp style pipes for whatever result is desired.
to quiet down a night stick replace the "open end cap" with 9 stacked discs and a closed end cap
( the nightstick open end cap is slight smaller diameter than the supertrapp supermeg open end cap which is equal to 10 discs)
all the discs and caps can be found on ebay cheap.
This method would retain the same flow characteristics, but the closed end cap would block high tinny frequencies.
Exhaust gasses are forced through a "w" shaped passage in the disc stack, this breaks up sound waves while retaining flow.
I recently replaced my supermegs ( 12 years old) when a couple of nightsticks became available cheap ( cheaper than buying replacement packing) I'm using the closed end caps and bout 15 discs right and 8 discs left on my 09 no cat stock headers.
I've been using supertrapps on a number of harleys for over 20 years.
Mike
to quiet down a night stick replace the "open end cap" with 9 stacked discs and a closed end cap
( the nightstick open end cap is slight smaller diameter than the supertrapp supermeg open end cap which is equal to 10 discs)
all the discs and caps can be found on ebay cheap.
This method would retain the same flow characteristics, but the closed end cap would block high tinny frequencies.
Exhaust gasses are forced through a "w" shaped passage in the disc stack, this breaks up sound waves while retaining flow.
I recently replaced my supermegs ( 12 years old) when a couple of nightsticks became available cheap ( cheaper than buying replacement packing) I'm using the closed end caps and bout 15 discs right and 8 discs left on my 09 no cat stock headers.
I've been using supertrapps on a number of harleys for over 20 years.
Mike
Last edited by mkguitar; 11-23-2011 at 03:05 PM.
#15
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Psycho Dave
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07-12-2017 02:27 PM