is there any books or articles that you can suggest to dispel some of the mystery of tuning EFI.
I'm after good books or articles, something that will help put all the technical talk into layman terms.
I have looked at motorworks books "how to tune and modify engine management systems" and " building and tuning high-performance electronic fuel injection" both books were very automotive systems specific and were not what I was looking for. although there was good info in the books the price tag wasnt worth the chapter or 2 of info that was relevant to my needs
any help or suggestions would be greatly appreciated
thanks

 

I'll do some scratching around, I know I've come across some in the past that I think is what you're looking for, but can't remember where. For basics, there are three types of EFI systems, TPS (throttle position sensor controlled), MAF (mass air flow sensor controlled) and SD (speed density) which is controlled by a MAP (manifold absolute pressure sensor). Harley used the TPS system until approx '02' and the SD system from '02' thru now. So if you find a good automobile EFI article, which should apply, look for those two types of systems to study.

 

Try this:

http://www.nightrider.com/biketech/m...efi_basics.htm

 

I've read that article......but thanks nonetheless.
I just put a Thundermax ECM (TPS system) on and want to learn how to get the most out of it without hurting the bike(or myself).
Thanks for your help.

 

I'm confused, that is a totally different question then you first asked. If you have an '06' and you put a Thundermax ECM TPS system on it tunes itself, according to their advertising assuming you have the tuning module.At this time I'm not sure where to send you for more EFIinfo but I'll keep looking.

 

here's a quote from Thundermax's site:


The ThunderMax is an Alpha-N based system, meaning it relies on rpm and throttle position only; it does not use data from the MAP sensor. The Harley's® uneven firing pulses and common plenum manifold can confuse the MAP sensor, and cause it to supply fuel and spark from the wrong block, resulting in poor performance. For this type of system to work properly, it requires many more “blocks” on the look-up table. When we designed our ECM we covered the bases with a system that operates using 1,984 points! Simply put, regardless of throttle position and engine RPM, there is a block on the look-up table to address the engine's needs in that situation. ThunderMax's processor can keep up with the ever- changing demands, rewarding you with a powerful engine that runs very smoothly and efficiently.

/quote

I also purchased the tuning module but have not installed it yet. I want to ride the bike for a few weeks with just the ECM so I can feel if the auto-tune was any"real" improvementbut I would like to "play" with my current base map in the mean time.
I would like to have a little tuningeducation before I go fockin with it though.
granted I can just re-load the original base map if I go in the wrong direction but I'm trying to A) eliminate some of the trial & error. B) understand what the EFI is doing and what exactly the Auto-tune is doing(or going to do once installed). I dont want to have this thing on the bike and not have any idea what its doing or how to use it.

basically I'm looking for some good reading material that I dont need a P.H.D. to comprehend
and issomewhat specific to my application.

 

Not up to speed on the ECM you're using. I have some experience with the Daytona Twin Tec which has some self tuning features. Basically the DTT ECM will read the AFR at the O2 sensors and then this figure will be in one of the cell blocks for the RPM and TPS readings, then you would get on the computer and apply the BLM, block learn multiplier and this block figure would be changed to a leaner/richer as needed until the bike is completely auto tuned. This doesn't mean you can't tweak some of the cells and get better tuning.

Basically your looking for a AFR reading that is not too lean or too rich but each bike has it's own appetite for fuel at different RPM's and Throttle ranges, also the altitude and barometric pressure come into playso those numbers might have to be tweaked to get optimum performance or fuel mileage, depending on your motor set up and location.

 

Speed, here's an opinion of mine that you may find interesting.

My hat isoff to anydesigner of EMSs and tunerswho can tune an EFI HD fast andwell, here's why I state this.

As many of us know there are three different EFI stratagies for controlling fuel and spark, TPS, MAP or MAF. Niether one of these work well for a street driven HD for these reasons.

TPS, the worse of the three because at a given throttle and RPM the engine load can vary dramatically requireing different fuel and spark cells., example going up or down a hill at a given TPS/RPM. This is why HD got away from that stratagy, however sometimesis the best stratagyfor very radical cammed raceengines where there is a limited vacuum signal for a MAP sensor.

MAP, better then TPS but much smoothing of theerratic vacuum signal to the MAP sensor and/or sensor signal smoothing has to be done with the HD due toit being a two cylinder and itsintake plenum arrangement. But this smoothing can be done at the sacrifice of a delayed signal to the ECM which can be overcome with tuningpenalties, still a better system then a TPS, which HD now uses.

MAF, a mass air flow meter, by far the best for drivability, mileage, emissions etc,and will compensate automatically foratmospheric orfor minor bolt on changes to the engine. But some air pulsation smoothing has to be done and requires more room, which we don't have. But soon, with tightning emissions requirements, I predict thatHD will be forced to go this route.

Carb followers, the engine design is also the reason why most HDs have an A/F ratio curve all over the graph at different loads and RPMs, EFI still better.

Like me, if you find yourself feeling that you're never done tuning, join the crowd.

 

Speed...just a thought.....

I noted you have an '06. I have a '06 FXDLI with a PCIII USB. Due to rough performance, I have been tweaking since I bought the bike new. Now that it is cold, the engines starts and runs rough. Just this week, I find out I have 8' fuel injectors P/N 27625-06. Service bulletin M-1185 calls for the dealer to evaluate the bike and if necessary replace with P/N 27626-06A, 25' injectors and so stamped on the part. I'm taking my bike in tomorrow for the dealer to hopefully replace the injectors. This is not a recall, but, an as needed bulletin. To find your injector P/N's look between the cylinder heads from the left side (looking around the horn). You'll see the injectors and be able to read the P/N's. The dealer is also to do a ECM upgrade after changing out the injectors. I don't know what this will do to my current map. But, I'm taking it to a performance bike shop next week for a dyno and custom map for the PCIII after all this work.

 

geargrinder, the above article that you linked from nightrider.com was GREAT! thats exactly what I was looking for.I would love to read more of the same. I was mistaken when I said the I had already read it as I have read other things on his site.

Roadrider18, I had the 25* injectors installed last week and that alone made a nice improvement.

thanks for the info guys! keep it coming..

and geargrinder, you are correct! I am quickly learning that tuning EFI is not a simple task and takes a good amount of knowledge.