Well, I find myself finally returning to the "read between the rides" since I am at a huge "between rides gap" at present.

Spring just cannot seem to be farther away in the Northeast here this weekend. It's march, hours away from turning the clocks ahead, and just days from the vernal eqinox, better known as spring. There is so much snow on the ground we probably will not be able to ride until September...but I am rapidly getting off topic....

I just read an article in the April 2008 issue of American Iron about the install of the S&S Quick Set-Up Stage I kit. It is on Page 186. Simply put: WTF? I believe I gained enough of an education into Stage I, V-Twins, H-D ideology, and the like to at least place a nice paper certificate on the wall of my pathetic little basement workshop, but this article just threw all of that out the window in one paragraph!

Chris Maida and his tech state that now "all 2007 HD owners (baggers, softails, and the like") can instantly gain 10 HP and 6 ft lbs of torque by adding this new intake breather/filter and exhaust kit. I read this brief article 4 times to be certain I read it properly. They claim no adjustment to the ECM is necessary with this kit because the electronic EFI with it's built-in O2 sensors automatically compensates and adjusts to the new intake and exhaust airflow.

First they installed the breather/filter. They fired the bike up and let it run for 15 minutes for the EIM to adjust and steady out. Then they replaced the exhaust, and afterward again, fired it up and let it "stabilize" via the ECM for 15 minutes - DONE!!

I have to admit albeit the photos in the article are black and white and a bit dark, I see no dramatic engineering and/or structural differences in this breather and exhaust from my own V&H Straight Shots/Ness BS. So why then did I need to install an ECM fuel management devise to richen the bike? I have a 2007. It has the O2 sensors installed and metered to the ECM. I typed my little fingers to nubs in spirited debates over the correct, or "best fit" module to use (PC, SERT, FP, TMax, etc.) and read each and every article, post and info any self-respecting DIY HD rider should. Never ONCE in any of the posts did I read that doing both intake and exhaust did NOT require an ECM mod.

Doing just slip-ons? Okay, that really doesn't require a new fuel module, BUT you're still going to run lean - just better sound. Adding a new breather? Now you MUST MUST MUST MUST install a fuel management module or over the long term, you will lean out and wear down your motor.

Help me out on this Trotter....and the rest of you "in the know" about this purported S&S Stage One with no ECM module required. If it sounds better, gains 10 horses and some torque...how can this be wrong? OR is the "shhhhhh...." part of the article the part where the bike will run so strong, you just won't worry that it's so lean your plugs will be white assheets!!!!

Opinions wanted as always bro's!!![8D]

 

i'd like to know myself.

 

bump !!! Would love some info on this

 

Ok Flynavy, I too am curious and certainly no expert, and have read likely as many threads and posts as you trying to get an understanding of the fuel management discussion/debates, and figure Geez, I just learned a lot! But maybe not enough it now seems!

Now, let me suggest as a non-expert that it may well have to do with something I read about narrow band vs wide band O2 sensors. Namely, and please correct me as I am out in uncharted territory here, the stock O2 narrow band sensors self-adjust and compensate within a narrow band of rpms and this is likely what the S&S article may be referring to as far as self-adjusting - and a good fuel management system takes over and allows adjustments of fuel/air over a wide range of rpms. And tuners like the T-Max do away with the original O2 sensors and provide their own wide band self-adjustment capability throughout the whole rpm range. I think. Maybe.

But this still begs the question, what happens to the engine in the S&S article in the rpm ranges not covered by the stock narrow band self-adjustments?

 

wow talk about a whole new can of worms opened up

 

I'm glad you posted this,I posted a thread on this same article a couple of weeks ago when I received my copy of AIM,by now more people have had a chance to read this article so the responce should be greater.

 

No expert here but I did come across thisdiscussion somewhere on one of the forums -

Maybe it helps ... maybe not?

Latus Motors

EFI Map matrix

How does the EFI system work in simple terms?
The EFI system used on most 06 and earlier models is an open loop system. This system is essentially “dumb” in the sense that it supplies fuel based only on the programmed (calibration) values in the tables that control the injectors. These calibration values are programmed by H-D to match the amount of/how an average stock motor, and its associated components, processes air at any given rpm, load and throttle opening. Environment changes (temperature, altitude, etc) are handled by offset tables which collect information from sensors (IAT, ET, MAP, etc) to modify the main tables. There are “Tuning Constants” that define the overall operational parameters such as motor size, injector size and rev limit. Another offset is the AFR table which uses a mathmatical formula to change the known tailpipe AFR base tuned value (when motors are stock using the original mapping) to the "desired AFR" for best fuel milage and low emmissions. The calibration values are fixed in the open loop system (until physically changed via remapping) and the ECM is incapable of identifying changes in air flow caused by component changes and corresponding needs to make fuel or other calibration changes to synchronize air/fuel or correct constants.
06 Dyna’s and all 07L models (except 07 V-rod) added O2 sensors in the exhaust systems to provide a “closed loop” capability. Production variables of the components used in and affecting the EFI system cause corresponding fuel and air flow differences from bike to bike as manufactured. The fixed, “open loop”, system does not compensate for these differences (just as it cannot compensate for component changes). The Closed Loop O2 sensing system provides feedback, within a limited AFR and specified operating range, to compensate for these production variables, reducing overall emissions. This added feature can compensate for mild component changes but does not memorize those changes (there is an "Addaptive Fuel Value" offset based on the avereage O2 required corrections which moves the entire VE tables rich /lean by +- 10%, remembered and constantly adjusting). This means that each time the ignition key is cycled, the O2 correction (O2 integrator) is at zero and must resample to establish the required correction. The bike may exhibit erratic running, until this is accomplished, each time it is restarted if the required correction values are large.

When do I need to recalibrate my ECM?
Whenever the amount of, or how the motor processes air is changed! Period!!! The major components influencing air flow are the exhaust system, air cleaner, motor size, heads and cams. If any of these are changed, the fuel (via the VE and AFR tables) and, typically, the tuning constants table in the ECM must change to match (synchronize) both the increases and decreases in air flow and physical characteristics of the motor caused by those component changes.
On “closed loop” models, the above is true when the changes exceed the O2’s capability to compensate, to reduce the amount of correction required of the O2's or to change tuning constants (motor size, injector size, etc).
In addition, there are certain “behind the scenes” tables that have strategies to add fuel for extended high rpm running or heat management, retard timing for knock control or heat management, injector off timing to reduce decal pop, change VE values (O2 equipped models AFV) or even to deal with high rpm downshifts in efforts to prevent engine damage or reduce ECM workload in extreme cases. Even with Race Tuner, we normally do not have access to these tables and cannot change them. These stratigies/tables may be different from cal to cal and so, having the most appropriate base cal he

 

Great read - thanks YNOT. So, maybe the S&S article guys figured they were within the +/- 10% ???? Or maybe did a flash?

 

Glad this has once again opened thecan of worms on fuel/air in EFI bikes.

Chip, they specifically mention in the article that nothing is done to the ECM. If a flash was performed, I have to give AIM the benefit of the doubt that it would not be something they did not mention.

But...like you say, the article certainly BEGS the question once again.


BTW, the article posted by YNOT from Latus was originally posted last year to this site by...oh yeah, me. I really thought after everything I had read, all the techs at HD I had spoken with, and even 2 indie techs, I had this thing licked. Now AIM and S&S step in and blow it all away with one paragraph.

Sometimes I wish I had a carb bike again. Actually, a lot of times I wish that.

Not to mention PSI Power has developed, patented, and now sells a a carb that can be 100% adjusted simply by removing the air cleaner - no jets. It provides a needle valve, and 2 other slide-type adjustments. It can be ordered to fit your engine, altitude, environment, and then fine tuned on the bike after you install and start once. Now THAT is a tweak I could easily live with.

 

Well Tim, all I can conclude from this is that with the S&S set-up, the AIM folk do not believe their changes require a recalibration of the ECM, and thus based on the above Latus description of the closed loop system on '06-'07 (and probably '08) models, the change of flow must not exceed the 02's capability to compensate, ie. within +-10% compensation. Perhaps it really isn't quite a full stage 1 intake system, maybe more like a stage .5 ????