Ok I jave heard conflicting reports about the ecm and the O2 sensors.
FIRST--
Some say the ECM will not compensate for the change of pipes and you must use some form of fuel enrichment to compensate, and that the 07's are coming from the factory extremely lean.

SECOND--
I just read on this forum a post stating that its some HD conspiracy,...paraphrase' to get us to spend money at the dealer, because the ECM does a very good job of managing mixture even with a pipe and ac change. And the dealers just want to sell you..

Just wondering if anyone out there has the true story about this. I have a 07 nighttrain, V&H said the 06 pipes wouldnt fit because that brackets and pipes were different,...Blatant Lie,...My 06 stepped drags fit perfectly. I'm using the pc3 with the O2 eliminators, and a kuryakin hypercharger with a K&N filter.

Now everything is fine with the bike, no engine code lites or anything, and she screams.... Just wondering if the BS... will continue on this subject.

 

First I will start by explaining how the narrowband O2 sensor works. Keep in mind the O2 sensor is only one of the many sensors which monitor engine functions in the EFI system. The narrowband O2 sensor can only accurately measure a small area within 14.7:1 stoichiometric air/fuel ratio range and works by providing a voltage signal to the ECM which then will continuously monitor the stoichiometric mid point crossover and adjust accordingly until the A/F is in the 14.7:1 range. The ECM is only using the O2 sensor feedback signal when the system is in closed loop mode. Closed loop mode occurs only under certain conditions which are light load, steady speed part throttle, constant mode under 3500 RPM's. It is only after these conditions that the will EFI go into closed loop mode and the ECM will adjust until the O2 crossover point is in the 14.7:1 A/F range. This is not at idle, not while accelerating, and certainly not at full throttle. Simply put, an narrowband O2 sensor only works for adjusting low load/cruise area and does not work well in performance applications because it can only monitor a small area within the stoichiometric A/F range. With that being said, yes the EFI can adjust itself on the 07 Harley models. That is if you consider the small amount of time it is in closed loop, and then when the ECM is able to adjust A/F it can only adjust it to 14.7:1 which is WAY too lean. The conspiracy is only dealers trying to get owners off their backs for poor running bikes due to EPA.

 

Pittguy - you're close but miss the mark. The 02's control to a bias voltage which is slightly richer than 14.7. A narrow band 02 can control from about .400 v to about .800 v. .800 would run you at about 14.2:1. The EFI Tuner alows you to control this.

The 3500 rpm thing - that sounds like old Buell tube frame info. The Delphi system will control idle all the way to over very high mph in closed loop of you want it to. For the Delphi to go onto closed loop on a Big Twin it the ET must be 86F, the 02 sensor must pass .450v momentarily (usually within 1 min) and it must be running for a certain amount of seconds - I forget how many but it's under a minute. Then as long as the MAP load coincides with a cell that has 14.6 in it, the 02's reference the bias table. I have plenty of HD's running around at 14.2 in the cruise range. as soon as you accelerate at a MAP load higher than one that has 14.6 it goes into open loop (your base map) and it also goes into open loop on decel.

If you look at the EFI Tuner, the AF table uses 14.6 as the trigger to look at the 02's. Then the Bias Voltage table allows you to set the voltage you want to control to.

 

So does this mean that the ecm's map is the real culprit in these bikes running lean?

The O2's are just there for epa "test" purposes? and really dont effect the actual performance of the bike?

Ok, heres the other ?, can the ecm manage the pipe ac change itself or will the stock "lean" map kill it?

 

The map in the ECm has a particular voltage to control to in closed loop. Adding a powercommander, etc will only fight the 02's. Using 02 eliminators makes you rely completely on the map in the pc, and if you get fuel with a higher alcohol content or anything, the bike will run differently. THe EFi tuner allows you to change the voltage the 02's control t0. It also allows you to run completely off the map without the 02's.

The 07's will accept a basic slip on and air cleaner and not have issues. For optimal power, the fuel should be adjusted for open loop operation as the bike goes in and out of open/closed loop. WOT is open loop, more than light to mid acceleration is open loop, decel is open loop. the 02's have the ability to control from idle all the way to where any person would be cruising.

 

so its okay to add ac/pipes to my 06 dyna (has 02 sensors) and the bike would run w/o probs?

im so confused... most sa y no add sert or download or pc3.

WHAT WILL HAPPEN IF I DONT DO A SERT OR PCIII OR DOWN LOAD?

will i get a super lean motor or what? will i burn a valve fry a plug?

thanks, but i just want to be sure before i put my $ down on my pipes and ac

blob

 

To (maybe) stem some confusion, lets go back to the basics. The engine is just an air pump. It breathes in X amount of air, and is fed Y amount of fuel. Your AFR is X:Y, Air:Fuel. If the first number is high (like 15) the mixture is lean. If the number is low (like 10) the mixture is rich. That's basics of it.

In order to make good power and run smoothly, you want your ratio to be somewhere around 13.5:1. The ideal mixture according to the EPA is exactly 14.7:1. For a variety of reasons, a stock H-D is even a little leaner than that. Lets pick a number and say 15.7:1. The bike runs OK, meets emissions standards, and gets good mileage.

Where do the O2 sensors come in? They are another feedback and control circuit in the system. There are a variety of them, like TPS and MAP, that feed engine status information to the computer. The computer takes that information and feeds in a certain amount of fuel based on the amount of air that the engine is assumed to be moving. The O2 sensors then read the exhaust, and check to see if the mixture is exactly right. If not, the computer adjusts so it is right. It's a positive feedback system. But it only works in a very narrow range. And remember the stock system is pretty lean already.

What happens when you change the pipes and air cleaner? If you pick the wrong parts, your air flow won't change. If your air flow doesn't change, then the fuel flow doesn't need to change either. The bike may look and sound better, but it runs exactly the same as stock; regardless of what the Butt-O-Meter says.

If you pick the right parts, air flow will be improved. More air flows in and out of the engine. If you don't add additional fuel, it will run even leaner than stock - and that's a bad thing. The O2 sensors can adjust for some of that, but only about 15-20%.

In a nutshell, if the new parts do not require a fuel curve adjustment you've probably wasted your money.

 

thanx for clearing that up. i will be adding ness big sucker and slipons in the winter, so i will then

have a download added by the dealer.

its also confusing that most harley magazines are saying that its fine to add ac and pipes

w/o tuning on the new bikes.
blob

 

Magazines are funded.

 

This is my first post or reply on this site and I am sure I will get many opinions but... I to have gotten very different and conflicting information on this subject as well. I have a new 07 Street Glide with 1500 miles on it. I just went to the dealer today to check on pipe availability for 07's after they convinced me earlier that 06 pipes or slip ons would not work. This time I talked with a different guy who sounded like he knew what he was saying. He convinced me that the 06 pipes from Thunderheader would work and I am going by to hear his bike Friday to decide if I like the sound of the 2 into 1. With the earlier info I recieved I also was convinced that I was going to add the pipes, air kit and the race tuner for the best possible tuning of the bike. The race tuner would give better results over the power commander and have the ability to tune each cylinder idividually which the power commander does not do.

Now I find this forum here and read this post and am sitting here wondering why I am going to spend the money for the racetuner. Not to mention the 70 bucks an hr for the tuning which he said could be from 1 to 4 hrs not to exceed 280 dollars even if it took 6 hrs.

Can I use 06 pipes? Do I need a race tuner? Do I pick a dealer and just trust them to be all knowlagable? Or do I get all my info and then come to you guys to help me figure what is or is not correct?

I am going with the last question and going to give you guys a shot to point me in the right direction.

PLEASE HELP!