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Discussion Starter · #1 ·
I am posting this for those that have questions about the SERT and may be a bit shy about the tuning methods;

I have no experience using the SERT other than on my current bike. I do, however, have a lot of experinece using ECM programming software from my LT-1 and LS-1 GM car racing past. The LS1edit software was damn near identical to what I see with the SERT. In fact, the data collection portion is identical except for the exclusion of the O2 readings.

Just a few pointers from someone who learns the 'hard way';

1. Take iddy biddy steps. Never make large 'wholesale' changes to any of the paramiters.

2. Patience is the key. Understan that you will not make one program change and be done.

The key to using SERT is to focus on one area at a time. For instance, on my bike I started with a canned map. I have made eight revisions to the programming just in the low RPM, low throttle area.

If you try to do too much at one time, you will get lost....
 

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michael:

Thanks for sharing your findings here!

Many have stated that there are some "givens" to starting with a canned map in that most riders immediately notice some sort of decel pop right off the bat.

Seems the concensus so far is to reduce the Decel Enleanment as much as 50% and add about 5%-7% to the VE tables at 0 and 2% Throttle up to ~4000 RPM. Another rider claims bumping the spark advance to
add 5degrees advance to both front and rear cyl in the 20 and 30 columns from 1250 to 3000 RPM
was necessary to get rid of decel popping.

Any comments as to how your experiences may relate to the above?

Am also interested in your reasons for attacking the low rpm, low throttle area.

:thanks:

:cheers:
 

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Discussion Starter · #3 ·
I'm on rev. 11 today. Like I said before, I like to take one problem at a time, I'm just simple minded.

So far, my primary focus has been in the low throttle position and medium engine load area. The map that I started with was for a cam that had a scant more duration and more lift than the cam I am using.

From my past experience, I feel that the 'canned' map that I started with was a typical 'dyon' map. So far I have no complaints about wide open throttle operation, which would be the typical operation of a dyno.

The areas that I have been tuning are from 1500 to 2750, and MAP from 30 to 60. This is where I notice the bike is eather falling on it's face, or studdering and popping like hell when I try to ease into the thottle.
 

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Discussion Starter · #4 ·
Rev 12 now, going to Rev. 13.

I've finally managed to get enough fuel to the engine. I'm really shocked at how much I've had to add to the canned map. The original map specs we're for a build just like mine, except the map was for SE-257 and I'm running SE-211.

I have only a few situations that still give me a stumble and pop. Mostly right around the 50mph/5th gear mark. It will run fine at steady throttle (steady low MAP and RPM) but a gradual increase in throttle (increased load~MAP) causes popping and hesitation. This is an extension of the problem I've had with the program from the beginning. I have been methodically decreasing the AFR in specific MAP/RPM cells until the problem goes away.

What I have noticed is that I have lost some of the low end during this excersise. The whole reason I've taken 12 revisions and tiny steps with the AFR was to hopefully not end up on the rich side, thus causing the bottom end to soften up.

I figure I have two ways to go now. One is to fool with the acceleration enrichment, to add more fuel only during accel. and leave the AFR alone. If this works I will likely go back to the AFR table and slowly increase the AFR to see if I get some of my low end zip back.

The other possibility is to add timing in the same areas that I've just added fuel. I may try to 'sneak' up on that. But, I'm a little hesitant because my bike is so loud, I may not be able to hear the detonation noises if that occurs. I'm going to try and get a laptop from work so I can do some data logs around the timing issue. (My wife said 'hell-no" to the idea of dragging her laptop around on the bike:nono:

Feed back and opinions are welcome. I'm in no way saying I'm an expert here, just sharring my experience.
 

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Hopalong
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I'm finding on almost all maps the low end spit and roll on hesitatation are from the VE #s being way too low-
The attachment is from an 06 dyna that needs tuning- the VEs are too low everywhere except ~2750, which tells me the initial calibration wasn't completed, just minor VE and afr adjustments.
A dyno w/afr sniffer is by far the fastest, and really most practical way to tune FI bikes.
it's making decent power.
 

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michael101 said:
Rev 12 now, going to Rev. 13.

I've finally managed to get enough fuel to the engine. I'm really shocked at how much I've had to add to the canned map. The original map specs we're for a build just like mine, except the map was for SE-257 and I'm running SE-211.

I have only a few situations that still give me a stumble and pop. Mostly right around the 50mph/5th gear mark. It will run fine at steady throttle (steady low MAP and RPM) but a gradual increase in throttle (increased load~MAP) causes popping and hesitation. This is an extension of the problem I've had with the program from the beginning. I have been methodically decreasing the AFR in specific MAP/RPM cells until the problem goes away.

What I have noticed is that I have lost some of the low end during this excersise. The whole reason I've taken 12 revisions and tiny steps with the AFR was to hopefully not end up on the rich side, thus causing the bottom end to soften up.

I figure I have two ways to go now. One is to fool with the acceleration enrichment, to add more fuel only during accel. and leave the AFR alone. If this works I will likely go back to the AFR table and slowly increase the AFR to see if I get some of my low end zip back.

The other possibility is to add timing in the same areas that I've just added fuel. I may try to 'sneak' up on that. But, I'm a little hesitant because my bike is so loud, I may not be able to hear the detonation noises if that occurs. I'm going to try and get a laptop from work so I can do some data logs around the timing issue. (My wife said 'hell-no" to the idea of dragging her laptop around on the bike:nono:

Feed back and opinions are welcome. I'm in no way saying I'm an expert here, just sharring my experience.
michael: It appears your adjusting the AFR tables, maybe in basic mode? If so, I would definitely take a look at adjusting the VE tables and/or Spark Tables in Advanced Mode.

I'm just now, after several Data Recordings going to reduce the AFR Table slightly in hopes of keeping the Injectors from taking a nap. :gun:

Don't remember while writing this what bike your working on, but IMO the '05 Dyna/Softail maps are probably the best H-D designed though they will surely be lean down low.

A beginner here too; and I apologize if I'm reading your procedures wrong.

good luck!

:cheers:
 

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Discussion Starter · #7 ·
I appreciate any and all input.....

I just returned from a week long trip in the hill country around Austin. That actually put more load on the bike than when I was testing, being 2 up the whole time and in hills. I still have a bad problem around 2k and any load.

It is like this. If I'm doing 50mph(2k rpm) and gently role on the throttle I get hesitation, and popping out of the exhaust. If I jamb the throttle it does ok. To me, this means the AFR's are lean, and the Accel Enrichment table is compensating.

I've noticed, however, that the bike is feeling sluggish compaired to the the original map. I think I will go back to that map and be a bit more detailed about the rpm band that I am messing with.

I have not touched the map above 2750rpm. My bike is a screaming animal at anything from 3k and up. Sounds a lot like a one or two pass dyno tune with little attention paid to actual riding conditions.

Keep up the comments and feed back, we're all trying to learn....:thanks:
 

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You mentioned in your post that you're slowly decreasing the AFR in certain cells, but it sounds like you're trying to make it richer. If you're tuning in basic mode and decreasing the value of the AFR cells, you're actually making them leaner. If you go to advanced mode and decrease the value, that will make them richer.

Not completely sure if I misread your post or not, just pointing out that you go in different directions to achieve the same results in the two modes.
 

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Snaps is bringing to light an important point..lots of guys have gone leaner when trying to go richer by being in the basic v.s the advanced mode.
Also...when using a canned map..after decreasing the target AF's down to 13.9 anyplace they are higher..all further enrichening or enleanment should be done with the VE tables in advanced mode for each cylinder.
 

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Discussion Starter · #10 ·
SYCLONE said:
Snaps is bringing to light an important point..lots of guys have gone leaner when trying to go richer by being in the basic v.s the advanced mode.
Also...when using a canned map..after decreasing the target AF's down to 13.9 anyplace they are higher..all further enrichening or enleanment should be done with the VE tables in advanced mode for each cylinder.

I should have mentioned. I've been in the advanced tuning mode, not the basic. But I have gone below the 13.9 figure on the AF table. I was not aware that I should have moved to the VE tables to make further adjustments. Maybe that will explain why I continue to have the same problem around 2k rpm even after driving the AFR down further and further. Thanks much..I'll try that.
 

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Hopalong
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The ECM has to be calibrated to actual air flow through the engine before it can calculate injector time accurately.
The ECM sets the amount of injector time needed to get to your desired AFR (aka 'pulse width') by taking the VE times displacement ( actual air flow). If the information the ECM has is innacurate, the results will be also be off. By adjusting the VE up or down, you're telling the ECM you actually have more or less airflow @ a certain spot, and the ECM can then adjust fuel flow accordingly.
ie: The system is lean (say, 15.6) at 1750RPM, 2% throttle. The VE at that spot in the table is 54 front cyl, and 50 rear cyl. Suppose desired AFR at that point is 13.8. Raise the VE at 1750 RPM, 2% throttle from 54 front to 61, and 50 rear to 56.5 and retest.
Hope this doesn't confuse things.
 
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