New exhaust pipe issues!

[Jamie Long]

I am in full agreement that sensor placement is extremely important, however along with the location it is just as important that you use the sensors within their limitations. Referring to the Bosch document, on page D4 it is best stated that "installation angles must be inspected and tested individually"

If you use the guidelines from the Bosch document under the "General Installation Instructions and Requirements" to determine what is right or wrong, even Harley's OEM sensors are NOT positioned correctly in the factory exhaust systems on most models according to Bosch's definition. The OEM sensors are not positioned at a min of 10 degree upward angle, several models are not mounted in a downward pipe, and the location on some of the rear O2 sensors and where they put them on some V Rod models just makes you scratch your head why they are mounted that way. Regardless, I am sure it goes back to Bosch's statment that "installation angles must be inspected and tested individually" and Harley did their fair share of testing to make things work properly.

Some of the aftermarket companies in question may or may not not have done their testing, however before suspecting O2 placement is causing a running or tuning issue it is very important to distinguish characteristics/issues directly related to improper placement from other O2 sensor issues such as exhaust reversion, the slightest exhaust leak, or cam timing, especially when there is alot of overlap. It is also very easy to assume it is something like O2 location if you have a bike that is not tuned properly. Some of the statements in this thread dont add up to the effects from improper O2 location, and for those users I recommend taking a second look at your tune along with your sensor location.

[FLTRI]

I am in full agreement that sensor placement is extremely important, however along with the location it is just as important that you use the sensors within their limitations. Referring to the Bosch document, on page D4 it is best stated that "installation angles must be inspected and tested individually"

If you use the guidelines from the Bosch document under the "General Installation Instructions and Requirements" to determine what is right or wrong, even Harley's OEM sensors are NOT positioned correctly in the factory exhaust systems on most models according to Bosch's definition. The OEM sensors are not positioned at a min of 10 degree upward angle, several models are not mounted in a downward pipe, and the location on some of the rear O2 sensors and where they put them on some V Rod models just makes you scratch your head why they are mounted that way. (yet they work) Regardless, I am sure it goes back to Bosch's statment that "installation angles must be inspected and tested individually" and Harley did their fair share of testing to make things work properly.

Some of the aftermarket companies in question may or may not not have done their testing, however before suspecting O2 placement is causing a running or tuning issue it is very important to distinguish characteristics/issues directly related to improper placement from other O2 sensor issues such as exhaust reversion, the slightest exhaust leak, or cam timing, especially when there is alot of overlap. It is also very easy to assume it is something like O2 location if you have a bike that is not tuned properly. Some of the statements in this thread dont add up to the effects from improper O2 location, and for those users I recommend taking a second look at your tune along with your sensor location.

Good information, observations, and advice. 

I believe the purpose of this thread is to bring awareness to possible reasons and explanations for why some folks were/are having running issues when their bike is in closed loop and the run quality deteriorates over time/miles.

I think this awareness has been good for all and while some may not admit it, they've learned from the sharing of knowledge in this thread.

Thanks for the input,
Bob

[1FSTRK]

Thanks to everyone that that has posted to this thread. We can never share to much information.
I had my sensors moved and the results are great.
Does anyone know of a chromer that will rechrome exhaust pipes? I have called a few and they seem to back away from harley pipes. If you know of someone that has good luck with this please let me know.

[Dennis The Menace]

Keep in mind, that 10 degree upward angle was meant to keep any condensation from entering the sensor and causing corrosion or shorting of the sensor head.  I am not sure how much issue there is with this on a Harley pipe, but just trying to call out that the angle spec was to keep water out of the sensor, not keep the tip in the exhast flow at a certain angle or relationship.  It still needs to be placed sufficiently in the flow.  So, good post, Jamie.

I am still debating what to do with my bungs...they are way too long.  Email to manufacturer went nowhere.

menace

[rbabos]

...and requires desperate measures to tune it in these areas.
Ron

Ron,
First let me say I have nothing to gain here other than to try to help.
I feel your frustration. There is a learning curve to tuning, any tuning... closed loop or open loop.
I believe you and others are discovering a good tuner earns the money they make.

In the end, tuners are responsible for identifying any issues and resolving them, either by fixing the problem as Tre_09UC has done (D&D corrected the O2 mounting) or work around them as strokerjlk does by tuning and leaving the bikes in open loop.

Those who have listened to Steve/TTS's advice, sent him the requested data for analysis, have ended up with a properly running closed loop bike, even if there was an area where, due to poor exhaust/O2 mounting design, must be left in open loop.

I often have to tune and leave some low rpm/tp areas (very small) in open loop due to poorly designed exhaust/sensor bungs and locations.

There have even been a couple bikes ie: straight pipes I chose to keep the entire mapping in open loop because of erroneous info fed to the sensors almost every rpm/tp.

I must state, from my personal experience, it is NOT Mastertune. It IS the exhaust design and/or sensor mounting issues that cause the closed loop system not to work properly.

You also have something I have never run into: Below 20kpa anywhere is decel FME. Something's simply not right with your bike OR you are spending your tuning efforts in the wrong place.

Hoping this is taken in the spirit in which it was intended,
Bob

Bob: Your opinions are always welcome. I hear what you are saying but think about this. How can an engine possibly run such high vacume if it has a problem. It cannot happen. Cam timing won't do it, small tb won't cause it and my timing might be a touch high in the 20kpa in the area it runs in, but dropping 3 degrees will not bring it up to the minimum 26 +. Trust me, I know my way around engines and these things are only a notch above a steam engine, however I cannot find a single cause to why this thing pulls such high vacume. Basically when things are incorrect low vacume is the issue, not the other way around. I have made this thing run probably better than some tuners could do with working around what tts couldn't do. Open loop is my friend here. I have not had one single technical reason as to why I have such low kpa's in this engine, from anybody, but rather my engine is fkd just because it will not tune in textbook TTS fashion. If I can get a logical reason for this low kpa I'd dive right in and check it out. So far no takers.
Ron

[FLTRI]

Ron,
Guess if it were me with this appearant anomaly, I would do a v-tune and a data recording, then send them, along with the calibration to TTS, who always offers to evaluate and diagnose customers' tuning issue(s).

IMO Steve will go to the end to resolve issues, but it requires the customer to provide the files and info in order to intelligently evaluate the problem and what is causing it/them. Have you sent your tuning files and data to TTS?

In the numerous tech calls I've made to TTS over the years I have never been disappointed with the advice and resolves to tuning issues I've encountered.

Just my experiences,
Bob

[arnold]

Thanks to everyone that that has posted to this thread. We can never share to much information.
I had my sensors moved and the results are great.
Does anyone know of a chromer that will rechrome exhaust pipes? I have called a few and they seem to back away from harley pipes. If you know of someone that has good luck with this please let me know.

Not chrome but looks interesting.
http://www.jet-hot.com/

[FLTRI]

FME, most coating companies want virgin metal, not after exhaust have been run through it.
Bob

[mike 120]

Curious, what is considered alot of cam overlap?

[rbabos]

Ron,
Guess if it were me with this appearant anomaly, I would do a v-tune and a data recording, then send them, along with the calibration to TTS, who always offers to evaluate and diagnose customers' tuning issue(s).

IMO Steve will go to the end to resolve issues, but it requires the customer to provide the files and info in order to intelligently evaluate the problem and what is causing it/them. Have you sent your tuning files and data to TTS?

In the numerous tech calls I've made to TTS over the years I have never been disappointed with the advice and resolves to tuning issues I've encountered.

Just my experiences,
Bob

I think a better approach would be contact the kit manufacuter to find out why the kpa is so low, or within their specs. Resolve it if possible and if not, do what I've already done to make it run decent. I've asked HQ before and most said it was lower than most, but I need to ask how low some of them have been logged at in the same load conditions.
Ron

[FLTRI]

...but I need to ask how low some of them have been logged at in the same load conditions.
Ron

Never seen a bike under load with idle/decel kpa values (<30kpa), but there's always a first time I guess.

Anyway, if all you need to manually tune is 20kpa it should be a piece of cake. Then leave the rest of the mapping in closed loop and have the best of both worlds.

Maybe if you send data the TTS they can decipher you dilemma. Didn't I read a post or 2 asking you to send data to TTS?

Why not go ahead and send Steve the info he needs to help you/us understand what is going on with your "unique" readings? 
Maybe we all can learn from your case. 
Bob

[rbabos]

...but I need to ask how low some of them have been logged at in the same load conditions.
Ron

Never seen a bike under load with idle/decel kpa values (<30kpa), but there's always a first time I guess.

Anyway, if all you need to manually tune is 20kpa it should be a piece of cake. Then leave the rest of the mapping in closed loop and have the best of both worlds.

Maybe if you send data the TTS they can decipher you dilemma. Didn't I read a post or 2 asking you to send data to TTS?

Why not go ahead and send Steve the info he needs to help you/us understand what is going on with your "unique" readings? 
Maybe we all can learn from your case. 
Bob

Bob: Even normal engines will pull below 30 kpa in decel, however I've seen 5-7 kpa at times in harder decels. Almost enough to pull the compression releases open between hits. I actually checked for that today and it doesn't, but the suction in the cyl and intake tract must be unreal non the less. The comp releases are right on the edge thought , since the slightest finger pressure trips them momentarily when in decel.
Ron

[glens]

Ron, if it were my problem, I'm pretty sure I'd determine the signal type of the MAP sensor (is it varying voltage output or varying resistance, for example?) and "shift" it ever so slightly in the direction I need.  This should serve to do what's necessary for you, and the only thing you'll be giving up is a little resolution on top (going "full throttle" MAP just a bit sooner).

If even only for testing purposes.

[rbabos]

Ron, if it were my problem, I'm pretty sure I'd determine the signal type of the MAP sensor (is it varying voltage output or varying resistance, for example?) and "shift" it ever so slightly in the direction I need.  This should serve to do what's necessary for you, and the only thing you'll be giving up is a little resolution on top (going "full throttle" MAP just a bit sooner).

If even only for testing purposes.

glens: Yes that would work, but I'm not electronically geekish enough to figure out where and what type of variable resistor to install. I could then shift the read kpa to 35+ at idle and not hit the lows I have now. This is the second sensor, which reads the same as the first one so that's ruled out. Since I'm not an electronics expert I came up with a mechanical fix instead. Drill and tap the manifold and install a fitting. Run a hose from here to the filtered side of the breather with another fitting to which I can screw various size restrictors inside to calibrate the desired intake leak to produce suitable kpa numbers. Then vtune again. Problem is,  both of our methods may be perceived as bordering into the twilight zone of tuning by the forum members. Even the words open loop almost causes a war. It would be nice to find out why some of these engines run this way and solve it with normal means, but failing that, what ohm range are we talking here?
Ron

[glens]

Ron, if it were my problem, I'm pretty sure I'd determine the signal type of the MAP sensor (is it varying voltage output or varying resistance, for example?) and "shift" it ever so slightly in the direction I need.  This should serve to do what's necessary for you, and the only thing you'll be giving up is a little resolution on top (going "full throttle" MAP just a bit sooner).

If even only for testing purposes.

glens: Yes that would work, but I'm not electronically geekish enough to figure out where and what type of variable resistor to install. I could then shift the read kpa to 35+ at idle and not hit the lows I have now. This is the second sensor, which reads the same as the first one so that's ruled out. Since I'm not an electronics expert I came up with a mechanical fix instead. Drill and tap the manifold and install a fitting. Run a hose from here to the filtered side of the breather with another fitting to which I can screw various size restrictors inside to calibrate the desired intake leak to produce suitable kpa numbers. Then vtune again. Problem is,  both of our methods may be perceived as bordering into the twilight zone of tuning by the forum members. Even the words open loop almost causes a war. It would be nice to find out why some of these engines run this way and solve it with normal means, but failing that, what ohm range are we talking here?
Ron

The electrical manual for the '09s says the MAP sensor voltage output (on a +5VDC cirucit) increases with pressure (well what it says as vacuum is applied the voltage should drop).  I know of a good way to get a percentage of the voltage with a couple of resistors, so long as that percentage is below 100.  I can't think of any easy ways to increase the voltage with just passive components like that.  That would require an "active" circuit (or a "vibrator" and a transformer and a rectifier, like an old tube car radio).  Probably even more doable actively, though.  Like with a little "volume" control for adjustment.  Probably could be done for little parts cost apart from the harness connectors.  I may look into it for you, but breathe in the meantime; it goes on the bottom of the list.

[glens]

But if a person had the ability, in every respect, to adjust the sampling times of the MAP sensor, this would likely solve your problem as well.  Just wishin' out loud...

[rbabos]

But if a person had the ability, in every respect, to adjust the sampling times of the MAP sensor, this would likely solve your problem as well.  Just wishin' out loud...

I might have the mechanical reason for it. It's a small tb in a large engine related, but have not tested it to be sure. Wife just started riding  and I can't seem to find the time to work in my testing. Some really sharp thinking from a forum member I have to say. Soon as he said it, it all made sense. I'll let him post if he wishes on the theory. All tuners are helpfull and I'm sure most have little secrets they like to keep, so just in case this is one of his, I can't spill my guts at this time.
Ron
Ron

[FLTRI]

Hey Ron,
Did you ever get around to sending Steve (TTS) the data he requested for analysis? I'm sure if he got it he could help you figger out why you are seeing the appearant anomalies in your system.
BUT ya got to send him the data to git help decifering.
Bob

[rbabos]

Hey Ron,
Did you ever get around to sending Steve (TTS) the data he requested for analysis? I'm sure if he got it he could help you figger out why you are seeing the appearant anomalies in your system.
BUT ya got to send him the data to git help decifering.
Bob

What's the point. He knows my kpa are too low to be able to correctly vtune my problem areas. I did keep plugging away like he suggested and most likely have found the cause to this ongoing nightmare. Almost positive a 50mm tb will make it all work, but I've been out of work for some time now and don't have the coin to get one. First I need to relocate the map sensor to prove the theory. Maybe Steve has already run accross this before, but usually a small tb on a large displacement are not the norm, so maybe not.
Ron

[FLTRI]

What's the point.?

"I'm sure if he got it he could help you figger out why you are seeing the appearant anomalies in your system.
BUT ya got to send him the data to git help decifering. "
I would bet you will learn something from it and best of all....it free!
Bob