Open loop / closed loop
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Intermediate
Joined: Nov 2006
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Open loop / closed loop
I tried this in the exhaust forum area, but think it fits better here.
I (think) I understand the benifits of having a closed loop system over an open loop system. As an owner of an '05 FLHT what I would like to know is how difficult would it be to switch to a closed loop system? I would rather not have O2 sensor bungs installed into a system. I would rather buy a true dual system for my bike that have the bungs (2 of them) in it when I by it. Who out there makes such systems? Samson/Caliber comes to mind, but are there others?
The next question is, who makes a system that "closes the loop" once I have a place to put the O2 sensors? Once again, ThunderMax comes to mind, who else out there has systems to close the loop? Unless I am reading things wrong, most of the systems I see are for data gathering and the user utilizes the data to adjust the fuel controller. Is his about right or am I missing some systems out there?
Lastly, don't most, if not all, of the systems control fuel alone and ignore the timing? I know that timing adjustment will just add to the complexity of tha whole package, but wouldn't it be of great help to make such adjustments along the way? What is out there to do this and are any of them integrated into the fuel control systems or are they stand alone?
My thoughts are to start out with a system that is a top end stage one that will allow plenty of growth down the road (ie. bigger bore, cams, head work) while spending next riding season learning the ins and outs of the system and all there is to gain from the high level of control the system affords.
Any educated thoughts? Well, other than that I am over thinking, and maybe under researching, the whole process.
I (think) I understand the benifits of having a closed loop system over an open loop system. As an owner of an '05 FLHT what I would like to know is how difficult would it be to switch to a closed loop system? I would rather not have O2 sensor bungs installed into a system. I would rather buy a true dual system for my bike that have the bungs (2 of them) in it when I by it. Who out there makes such systems? Samson/Caliber comes to mind, but are there others?
The next question is, who makes a system that "closes the loop" once I have a place to put the O2 sensors? Once again, ThunderMax comes to mind, who else out there has systems to close the loop? Unless I am reading things wrong, most of the systems I see are for data gathering and the user utilizes the data to adjust the fuel controller. Is his about right or am I missing some systems out there?
Lastly, don't most, if not all, of the systems control fuel alone and ignore the timing? I know that timing adjustment will just add to the complexity of tha whole package, but wouldn't it be of great help to make such adjustments along the way? What is out there to do this and are any of them integrated into the fuel control systems or are they stand alone?
My thoughts are to start out with a system that is a top end stage one that will allow plenty of growth down the road (ie. bigger bore, cams, head work) while spending next riding season learning the ins and outs of the system and all there is to gain from the high level of control the system affords.
Any educated thoughts? Well, other than that I am over thinking, and maybe under researching, the whole process.
Advanced
Joined: Jun 2006
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RE: Open loop / closed loop
Certainly there are some whohave gone that route and will counter this but if you have $1500 to spend, go buy the SERT and get it dynoed. Then you have about $900 to spend elsewhere and you will have a bike that runs as good as you would expect it to. Why add complexity?
Cruiser
Joined: Sep 2007
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RE: Open loop / closed loop
ORIGINAL: LazyLion
I tried this in the exhaust forum area, but think it fits better here.
I (think) I understand the benifits of having a closed loop system over an open loop system. As an owner of an '05 FLHT what I would like to know is how difficult would it be to switch to a closed loop system? I would rather not have O2 sensor bungs installed into a system. I would rather buy a true dual system for my bike that have the bungs (2 of them) in it when I by it. Who out there makes such systems? Samson/Caliber comes to mind, but are there others?
I tried this in the exhaust forum area, but think it fits better here.
I (think) I understand the benifits of having a closed loop system over an open loop system. As an owner of an '05 FLHT what I would like to know is how difficult would it be to switch to a closed loop system? I would rather not have O2 sensor bungs installed into a system. I would rather buy a true dual system for my bike that have the bungs (2 of them) in it when I by it. Who out there makes such systems? Samson/Caliber comes to mind, but are there others?
The next question is, who makes a system that "closes the loop" once I have a place to put the O2 sensors? Once again, ThunderMax comes to mind, who else out there has systems to close the loop? Unless I am reading things wrong, most of the systems I see are for data gathering and the user utilizes the data to adjust the fuel controller. Is his about right or am I missing some systems out there?
Lastly, don't most, if not all, of the systems control fuel alone and ignore the timing? I know that timing adjustment will just add to the complexity of tha whole package, but wouldn't it be of great help to make such adjustments along the way? What is out there to do this and are any of them integrated into the fuel control systems or are they stand alone?
My thoughts are to start out with a system that is a top end stage one that will allow plenty of growth down the road (ie. bigger bore, cams, head work) while spending next riding season learning the ins and outs of the system and all there is to gain from the high level of control the system affords.
1. I know Shooter64 (a member here), and Eastern Perf Cycles sells them for less than $700, so "saving" $900 is incorrect. Especially when you have to spend $300-400 for a SERT. That puts the Tmax at more like a $400 premium above the SERT.
2. You mention adding other stuff along the way. With a SERT, or a dyno-tuned DFO, you need to have a dyno tune each time you add something that changes the engine performance. I'll assume you know why. One or two trips to the dyno and you've spent the difference. With the Tmax, or other WBO2 ECM, you would just load a map to match your config, and let it tune.
3. As far as adding complexity to the bike (mentioned in another response), you have an ECM now, these units just replace or augment it. To me, complexity would be arranging to get the bike to and from the dyno shop each time I did something to it, not plugging in my computer, loading a new map, and riding it.
These are just my opinions, and I know there are people who have easy acces to a dyno or tuner-guy, so for them, the other route might make sense.
Road Captain
Joined: Jul 2007
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RE: Open loop / closed loop
I use and recommend the DTT/WEGO IID. It has everything your looking for. Just add the 07 (they have the twin 02 bungs)true dual exhaust system of your choice.
The T-Max and DTT*DO NOT*auto tune timing, but I know the DTT has a very simple timing chart modification. You use the mouse to pull/adjust the 3-D map table without numeric input. It`s very easy to change the timing curve. You(directions included) record the data you need and modify from there. It`s the best way to go IMO
Spend the money on a good tuner box with auto-tune and do it yourself. Every change you make can be tuned without a dyno or someone using your bike to learn on.[8D]
I bought the DTT and added RH-TD`s and a SE-A/C. The bike was auto tuned to match that setup and ran great. I even spanked a 95 kit with it.
I then added my RedShift 575 cams. Now I`m completing the auto tune for that as well. The bike runs excellent. Later on I plan to go with a 117 kit.The DTT will tune tothat too. I think the DTT and T-Max boxes are the only way to go.
The T-Max and DTT*DO NOT*auto tune timing, but I know the DTT has a very simple timing chart modification. You use the mouse to pull/adjust the 3-D map table without numeric input. It`s very easy to change the timing curve. You(directions included) record the data you need and modify from there. It`s the best way to go IMO
Spend the money on a good tuner box with auto-tune and do it yourself. Every change you make can be tuned without a dyno or someone using your bike to learn on.[8D]
I bought the DTT and added RH-TD`s and a SE-A/C. The bike was auto tuned to match that setup and ran great. I even spanked a 95 kit with it.
I then added my RedShift 575 cams. Now I`m completing the auto tune for that as well. The bike runs excellent. Later on I plan to go with a 117 kit.The DTT will tune tothat too. I think the DTT and T-Max boxes are the only way to go.
Intermediate
Joined: Jan 2013
Posts: 44
Likes: 13
From: Cape Cod
I just went with the TTS Mastertune for my 02 Glide... I went with a set of RB Racing LSR 2-1 C style +5inch slash cut. pipes... I know you said you want `a true duals set of pipes, but I had the crossover duals from the factory. They were pretty heavy, and not an overly efficient setup to produce power... Not sure That RB makes a set of true duals , though... but he will mount bungs for you for O2 sensors in any of his Pipes set-ups... and he does have O2sensors available, too... My bike was not equipped with O2 sensors from the factory, and my ECM is not designed for closed loop tuning... I think if you have the six pin Can Bus diagnostic cable you should be all set, and The TTS set up was pretty easy, even for an old, computer challenged guy like me... I'm thoroughly impressed with both the pipes and the TTS system... my bikes running better than it ever has! I think either the WEGO or RB racing AFR gauges may be the trick to any tuning I might want to attempt.... but as Mr Wizard said...in trying to tune my old style ECM, I may end up spending way more cash than makes sense for a given level of performance... I'm very happy with my bike and the way it's running now.
Just my two cents...
Just my two cents...
Seasoned HDF Member
Joined: May 2012
Posts: 32,934
Likes: 36,031
From: Carlsbad, CA
Just curious. What are the advantages of a closed loop system over a well tuned, **** loop system? Although not “closed loop” our EFI system make adjustments for Atmosperic pressure, engine temp, etc. Wouldn’t that essentially compensate for all the variables?
Intermediate
Joined: Jan 2013
Posts: 44
Likes: 13
From: Cape Cod
Hey G...
A closed loop system uses input from O2 sensors when it assess how much fuel to inject into the cylinder to hit a target Air Fuel Ratio. An open loop system refers to a pre-loaded map to inject fuel to hit the targeted Air Fuel ratio. Older bikes (pre-2005, generally with Harley/Delphi Fi ) with older ECMs generally run open loop systems. If your Harley doesn't have O2 sensors, it's most likely a open loop system. An open loop system can usually run ok and compensate for minor changes in your intake or exhaust system, but may need updates to the programming of it's ECM to run well with more extensive changes. Closed loop systems are found in newer Harleys, refer to the O2 sensors to adjust the Air Fuel Ratios, offer a bit more tuning flexibility and input, some have the capacity to provide an auto tune feature, and offer the capability to accommodate and be tuned for more aggressive changes to the engine.
Basically, there it is in a nutshell... hope that helps...
A closed loop system uses input from O2 sensors when it assess how much fuel to inject into the cylinder to hit a target Air Fuel Ratio. An open loop system refers to a pre-loaded map to inject fuel to hit the targeted Air Fuel ratio. Older bikes (pre-2005, generally with Harley/Delphi Fi ) with older ECMs generally run open loop systems. If your Harley doesn't have O2 sensors, it's most likely a open loop system. An open loop system can usually run ok and compensate for minor changes in your intake or exhaust system, but may need updates to the programming of it's ECM to run well with more extensive changes. Closed loop systems are found in newer Harleys, refer to the O2 sensors to adjust the Air Fuel Ratios, offer a bit more tuning flexibility and input, some have the capacity to provide an auto tune feature, and offer the capability to accommodate and be tuned for more aggressive changes to the engine.
Basically, there it is in a nutshell... hope that helps...
Last edited by rockett88s; Apr 17, 2020 at 01:47 PM.
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I dunno, what is the benefit of a **** loop? lol
Last edited by Ed Ramberger; Apr 17, 2020 at 06:49 PM.
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Grand HDF Member
Joined: Jun 2013
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From: Iowa
The PV also has wide band autotune but it is a piggy back system rather than ECM so it doesn't adjust the mapping and flow on the fly.
Closed loop is better than open loop and tuning because the fuel mixture is maintained in a closed loop to the tune given environmental differences like air pressure, humidity, engine and atmospheric temp. Without it you are tuned well to run on that dyno but performance will vary widely.
Closed loop is better than open loop and tuning because the fuel mixture is maintained in a closed loop to the tune given environmental differences like air pressure, humidity, engine and atmospheric temp. Without it you are tuned well to run on that dyno but performance will vary widely.