best tuner? besides tts?
Ultimate HDF Member
Joined: May 2008
Posts: 6,642
Likes: 48
From: Ogden, UT
+1 on ThunderMax w/ AutoTune (TMAT) ... it replaces the entire stock ECM ... have not looked at their website to see if they're compatible w/ the '12 models yet, though ... I understand there are some pretty radical changes to the electronics on the '12 models (I think they split the boards up between 'chassis' and 'motor') ....
I am super-pleased with my TMAT ... and the performance I've been getting
* * *
Rich if you had a significant difference in flow characteristics of the pipes (scavenging, for example) ... it could change the characteristics of the fill rate of the combustion chambers at higher RPMs ... doubtful it would be noticeable on a stock motor under 'normal' street riding conditions ... I can't really formulate a theory on how it would affect the EFI ... if it was a wide-band O2 system, the ECM should notice a richer or leaner condition in the exhaust under the affected conditions and compensate ... however, with narrow-band O2 sensors it might adversely affect the AFR ... just thinking out loud here ....
* * *
dyna bomb - welcome aboard and good luck with your bike build ...
R/
'Chop
I am super-pleased with my TMAT ... and the performance I've been getting
* * *
Rich if you had a significant difference in flow characteristics of the pipes (scavenging, for example) ... it could change the characteristics of the fill rate of the combustion chambers at higher RPMs ... doubtful it would be noticeable on a stock motor under 'normal' street riding conditions ... I can't really formulate a theory on how it would affect the EFI ... if it was a wide-band O2 system, the ECM should notice a richer or leaner condition in the exhaust under the affected conditions and compensate ... however, with narrow-band O2 sensors it might adversely affect the AFR ... just thinking out loud here ....
* * *
dyna bomb - welcome aboard and good luck with your bike build ...
R/
'Chop
ThunderMax Gen II EFI Module w/AutoTune modular combo, for ’01-'12 Big Twin equipped with cable-type Delphi EFI (not 2008-up Touring Models) - $899.95 # 309-360
Intermediate
Joined: Aug 2007
Posts: 38
Likes: 2
Heck, I'm not claiming to be an expert, if I knew it all I wouldn't bother with forums. I'm probably wrong but my reasoning goes something like this: Scavenging is determined in part by header diameter and the length of the pipe so if you change either of those you change the reversion characteristics which will affect the mix in the cylinder. I don't know. Maybe I was just dupped by the V&H instruction manual that said to install a fuel management system with new pipes. They could just be trying to sell gizmos I guess. Like I said, I like to read. I'm not too smart though.
Ultimate HDF Member
Joined: May 2008
Posts: 6,642
Likes: 48
From: Ogden, UT
Of course V&H wants to sell their tuner.
As far as reversion and air flow due to exhaust changes, while it may make some very minor changes to how the air flows out of the combustion chamber, it still does not allow more air to enter the combustion chamber and the stock ECM is capable of compensating for these minor changes to keep the AFR within it's preset limits.
As far as reversion and air flow due to exhaust changes, while it may make some very minor changes to how the air flows out of the combustion chamber, it still does not allow more air to enter the combustion chamber and the stock ECM is capable of compensating for these minor changes to keep the AFR within it's preset limits.
Intermediate
Joined: Aug 2007
Posts: 38
Likes: 2
Of course V&H wants to sell their tuner.
As far as reversion and air flow due to exhaust changes, while it may make some very minor changes to how the air flows out of the combustion chamber, it still does not allow more air to enter the combustion chamber and the stock ECM is capable of compensating for these minor changes to keep the AFR within it's preset limits.
As far as reversion and air flow due to exhaust changes, while it may make some very minor changes to how the air flows out of the combustion chamber, it still does not allow more air to enter the combustion chamber and the stock ECM is capable of compensating for these minor changes to keep the AFR within it's preset limits.
Road Warrior
Joined: Apr 2009
Posts: 1,360
Likes: 4
Just remember guys that the stock O2 sensor is accurate in establishing if the O2 level in the exhaust stream is more or less than ideal (ideal determined by the factory). The ECU will attempt to add or subtract fuel to maintain the ideal O2 level. Adding an exhaust that properly places the sensor in the exhaust stream and one that does not allow air to come back up the exhaust pipe to where the sensor is located (reversion) will not affect the operating baseline AFR enough to notice. A few low restrictive exhausts could allow air back far enough to effect the sensor, but simply installing a slip on will not, especially if you have a cat. This reversion often results in the decel pop often heard from poorly tuned bikes.
So you say why all the fuss? Well, the first thing to keep in mind is that, to make large adjustments, the ECU has to work hard and is unhappy. The smaller adjustments the ECU needs to make the better the feel of the bike. It just is what it is.
The second thing to keep in mind is that the ECU uses O2 sensor input, and therefore makes accurate adjustments, only during “closed loop” operation, which is steady state cruising more or less. When the throttle moves or is pegged at WOT, the ECU will guess what fuel and spark to use based on the factory program plus what it learned from closed loop. The factory program, however, is based on a less efficient air pump model than the one they would use for an engine with less backpressure and low restriction filter. Things are not linear, so we observe the bike running a little leaner than ideal. If you stay away from WOT runs, you should be OK, however. HD will sell you a map (so called download) that uses a different model that compensates for less restriction (but again adjusts to the factory definition of ideal).
A third thing to keep in mind is that the cat backpressure will moderate changes, but they are very temperamental to overly rich mixtures dumping in unburned fuel. Luckily low restriction mufflers and air filter causes the ECU error on the lean side. But you don’t want to be too far off regardless.
BTW, because the stock sensor is so accurate and reliable, this ECU guessing at the fuel and timing based on closed loop operation approach is done very well when the bike is tuned, and with excellent street results. During a tune, the efficiency of your engine is determined and then combined with what the vendor (or you) thinks is an ideal base tune (not the factory ideal) to develop a corresponding ECU map. A dyno tuner pro will go on to double check that what he thought happens actually happens. The alternate approach of trying to measure O2 concentrations over a broader range can also be effective on the street, but has not been proven to provide a better street tune. An accurate enough broad band sensor for the HD application is just not available at practical cost. Life is a compromise, the compromises are different, but you can acheive much riding sataisfaction using either approach. Broad band sensors have been used more accurately in some car environments, but those environments are closely controlled, but I digress…….
So all things considered, throwing slip on and a low restriction air filter on is perfectly safe. You may not like the way the bike feels, but it will be OK. You certainly won’t be making max power, and may actually hurt performance. Just don’t ride the bike as if its been stolen, i.e. keeping off the WOT as much as possible.
So you say why all the fuss? Well, the first thing to keep in mind is that, to make large adjustments, the ECU has to work hard and is unhappy. The smaller adjustments the ECU needs to make the better the feel of the bike. It just is what it is.
The second thing to keep in mind is that the ECU uses O2 sensor input, and therefore makes accurate adjustments, only during “closed loop” operation, which is steady state cruising more or less. When the throttle moves or is pegged at WOT, the ECU will guess what fuel and spark to use based on the factory program plus what it learned from closed loop. The factory program, however, is based on a less efficient air pump model than the one they would use for an engine with less backpressure and low restriction filter. Things are not linear, so we observe the bike running a little leaner than ideal. If you stay away from WOT runs, you should be OK, however. HD will sell you a map (so called download) that uses a different model that compensates for less restriction (but again adjusts to the factory definition of ideal).
A third thing to keep in mind is that the cat backpressure will moderate changes, but they are very temperamental to overly rich mixtures dumping in unburned fuel. Luckily low restriction mufflers and air filter causes the ECU error on the lean side. But you don’t want to be too far off regardless.
BTW, because the stock sensor is so accurate and reliable, this ECU guessing at the fuel and timing based on closed loop operation approach is done very well when the bike is tuned, and with excellent street results. During a tune, the efficiency of your engine is determined and then combined with what the vendor (or you) thinks is an ideal base tune (not the factory ideal) to develop a corresponding ECU map. A dyno tuner pro will go on to double check that what he thought happens actually happens. The alternate approach of trying to measure O2 concentrations over a broader range can also be effective on the street, but has not been proven to provide a better street tune. An accurate enough broad band sensor for the HD application is just not available at practical cost. Life is a compromise, the compromises are different, but you can acheive much riding sataisfaction using either approach. Broad band sensors have been used more accurately in some car environments, but those environments are closely controlled, but I digress…….
So all things considered, throwing slip on and a low restriction air filter on is perfectly safe. You may not like the way the bike feels, but it will be OK. You certainly won’t be making max power, and may actually hurt performance. Just don’t ride the bike as if its been stolen, i.e. keeping off the WOT as much as possible.
Last edited by ColdCase; Oct 13, 2011 at 11:50 AM.
Tourer
Joined: Jan 2011
Posts: 440
Likes: 0
+1 i've never tuned my cars for an intake and exhaust. FWIW i have noticed zero difference with the pcv5 tuner.
Intermediate
Joined: Aug 2007
Posts: 38
Likes: 2
[COLOR=black][FONT=Verdana]So all things considered, throwing slip on and a low restriction air filter on is perfectly safe. You may not like the way the bike feels, but it will be OK. You certainly wont be making max power, and may actually hurt performance. Just dont ride the bike as if its been stolen, i.e. keeping off the WOT as much as possible.
Road Warrior
Joined: Apr 2009
Posts: 1,360
Likes: 4
As long as the pipe places the O2 sensors properly, and you stay off WOT as much as you can, you will be OK. Some brands pay more attention to detail and place O2 sensors better than others. I don't know which ones are best off hand, but the bungs being close to where the stock ones are located and at the same depth should be a good sign.
If you plan to eventually use something like the TTS tuning kit or the HD tuner or an auto tune, you will want the sensor bungs in an ideal location anyway. All the tuning systems that use O2 sensors rely on good sensor data. For those products that disable/eliminate O2 sensors, or you choose to run entirely open loop, it is a don't care.
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Intermediate
Joined: Aug 2007
Posts: 38
Likes: 2
As long as the pipe places the O2 sensors properly, and you stay off WOT as much as you can, you will be OK. Some brands pay more attention to detail and place O2 sensors better than others. I don't know which ones are best off hand, but the bungs being close to where the stock ones are located and at the same depth should be a good sign.
If you plan to eventually use something like the TTS tuning kit or the HD tuner or an auto tune, you will want the sensor bungs in an ideal location anyway. All the tuning systems that use O2 sensors rely on good sensor data. For those products that disable/eliminate O2 sensors, or you choose to run entirely open loop, it is a don't care.
If you plan to eventually use something like the TTS tuning kit or the HD tuner or an auto tune, you will want the sensor bungs in an ideal location anyway. All the tuning systems that use O2 sensors rely on good sensor data. For those products that disable/eliminate O2 sensors, or you choose to run entirely open loop, it is a don't care.
Road Warrior
Joined: Apr 2009
Posts: 1,360
Likes: 4
A lot of guys put slip ons on and are happy, but there are no guarantees. Those that put on entire exhaust systems seem to be looking more for performance than style and will typically also want to get the most out of them by tuning. I've heard stories of throwing systems on without tuning that eventually discolor the pipe's chrome finish.. so I personally wouldn't want to take the chance unless I was babying the bike... and what fun it that. 