Knowledge Is power,,,
#1
05-30-2011, 05:30 PM
Knowledge Is power,,,
Exhaust Info,,,,,
Knocking out the center deflector on a set of already overly stuffy pipes isn't going to require anything. Not to mention, being able to feel anything.
Even after knocking that plate out, in most cases, you either punch a hole in it and leave remaining plate, or you knock it backwards, creating a flap that catches exhaust.
That deflector was placed there to divert ALL EXHAUST through tight packing to absorb a high percentage of the shock waves, resulting in a super quiet muffler. Even with out the deflector, most of the pulses are absorbed during idle and during midrange operation. At top end, the EPA doesn't monitor output, so most bikes have sufficient jetting regarding their main jets, resulting in MORE HPs after the mod, due to less restriction.
While adding free-flow pipes (metal deflector baffles with no packing) will require rejetting, doing the baffelectomy-I to a set of stock pipes does absolutely nothing but add a little more sound on acceleration.
If you think you "feel" a low end torque loss with that small mod, then you're backside is more sensative then most Dynos.....
Regarding jetting and why.....
There are three things you can tune for exhaust: sonic pulse, thermal pulse and exhaust velocity. The length of the pipe controls the first two, but gas velocity is controlled by the pipe diameter and baffeling. (reversion)
A sonic pulse is created when the exhaust valve slams shut and a strong wave is made that starts down the pipe. When it reaches the end of the pipe (hitting baffles) it turns around and heads back to the combustion chamber. The hot gas leaving the combustion chamber creates the ”thermal pulse.”
Ideal exhaust velocity is 300 feet per minute and numerous factors influence this. 883s, 1200s and 1340s need a 1 3/4-inch pipe to stay near this gas speed.
Valve overlap is that the wave will travel through the open intake valve and down the intake tract carrying some fuel out of the carb (a condition called "fuel standoff"). This causes the poor low-speed performance of short drag pipes or unbaffled/low baffled pipes.
__________________
Knocking out the center deflector on a set of already overly stuffy pipes isn't going to require anything. Not to mention, being able to feel anything.
Even after knocking that plate out, in most cases, you either punch a hole in it and leave remaining plate, or you knock it backwards, creating a flap that catches exhaust.
That deflector was placed there to divert ALL EXHAUST through tight packing to absorb a high percentage of the shock waves, resulting in a super quiet muffler. Even with out the deflector, most of the pulses are absorbed during idle and during midrange operation. At top end, the EPA doesn't monitor output, so most bikes have sufficient jetting regarding their main jets, resulting in MORE HPs after the mod, due to less restriction.
While adding free-flow pipes (metal deflector baffles with no packing) will require rejetting, doing the baffelectomy-I to a set of stock pipes does absolutely nothing but add a little more sound on acceleration.
If you think you "feel" a low end torque loss with that small mod, then you're backside is more sensative then most Dynos.....
Regarding jetting and why.....
There are three things you can tune for exhaust: sonic pulse, thermal pulse and exhaust velocity. The length of the pipe controls the first two, but gas velocity is controlled by the pipe diameter and baffeling. (reversion)
A sonic pulse is created when the exhaust valve slams shut and a strong wave is made that starts down the pipe. When it reaches the end of the pipe (hitting baffles) it turns around and heads back to the combustion chamber. The hot gas leaving the combustion chamber creates the ”thermal pulse.”
Ideal exhaust velocity is 300 feet per minute and numerous factors influence this. 883s, 1200s and 1340s need a 1 3/4-inch pipe to stay near this gas speed.
Valve overlap is that the wave will travel through the open intake valve and down the intake tract carrying some fuel out of the carb (a condition called "fuel standoff"). This causes the poor low-speed performance of short drag pipes or unbaffled/low baffled pipes.
__________________
#2
05-30-2011, 05:31 PM
Fuel management
HD allows for replacement of mufflers only, with no ECU changes or fuel adders/fuel management Thousands of riders do it with not one complaint. If anything, they feel an improvement, due to reduction of overly stuffy mufflers and the engine is allowed to exhale better. The engine is a pump. Air in/air out. More air in/out, the more HPs it produces. Stock bikes aren't even close to their peak performance, off the showroom floor.
Changing mufflers is a much larger change then knocking out the deflectors in stock mufflers. On their best day, stock pipes with knocked out deflectors aren't half as free-flowing as a set of SE pipes, Rineharts or XYZ. They still meet EPA noise requirements on most levels, at idle.
To boot, 2008 and newer bikes have an adjustable closed loop system to compensate for small changes, unlike the much narrower parameters that were on the older bikes, with 2010 and newer being even more sensative.
OEM closed loop H-D Delphi ECM will maintain the fuel mixture at the 14.6:1 AFR it came from the factory without any ECM remapping. (Excluding cold starts at 12:1, and WOT at about 12.5:1)
This mapping has a narrow window for changes, (also related to the narrowband sensors they use) and works mostly in the middle 40% range, where most of us ride. After changing mufflers and even the air intake, on 2010-up models, the bike will still return the parameters to 14.6:1, but there have been cases where the a/f ratios have been as high as 15:1. This is a recipe for heat and disaster.... This is why most people will recommend a fuel management system, to add more fuel not JUST for performance, but to bring engine temps (cylinder/head) down.
It's a tad more complicated then this, but simplified, this is it.
My point being: I see a rider In Brewton, Alabama. He's close to sea level. A bike can run leanest at sea level where as a bike at higher elevations will run richer. With his location AND pipe mod....perhaps he's at the end of the limit, once his bike is warm and in closed loop, due to another reason.
There's 3 key sensors on the bike that take readings (other then the O2 sensors which would be 4) and maybe one of them is slow, or not reading correctly. A simple scan test could determine this.
IAT sensor: (Intake Air Temp) Reads the temps of the air entering the engine. Warm/hot air contains less oxygen then cooler or cold air. Living in a hot climate and having a failed/slow sensor can cause a lean condition. Lean equals less power...
MAP sensor: (Manifold Absolute Temp) This sensor sends signals to the ECU regarding intake manifold pressure and ambient barometric pressure. Intake pressure tells the ECU information about speed and load on the engine. Ambient pressure is in regards to elevation. Both effect a/f ratios........
ET sensor: (engine temp) Senses heat in the front head and tells the ECU if the engine is at full temp or not, and when to go into closed loop, from open loop.
Even a slow or doggy O2 sensor can be an issue.
To clear the air: I'm saying the low end loss (if it exists) isn't due to the small pipe mod that he made, as was claimed. ESPECIALLY with an ECU that senses changes, and readjusts for losses, back to the original parameters of 14.6:1 air fuel ratio.
If the ECU corrects the problem, there is no problem, and no change according to the ECU and performance remains the same. That's how and why it was designed. (Well...actually to maintain a consistent a/f ratio for EPA standards)
If the ECU or sensors aren't doing their jobs, then and only then, will a change be noticed, whether it's on a Dyno, or on the road.
Changing mufflers is a much larger change then knocking out the deflectors in stock mufflers. On their best day, stock pipes with knocked out deflectors aren't half as free-flowing as a set of SE pipes, Rineharts or XYZ. They still meet EPA noise requirements on most levels, at idle.
To boot, 2008 and newer bikes have an adjustable closed loop system to compensate for small changes, unlike the much narrower parameters that were on the older bikes, with 2010 and newer being even more sensative.
OEM closed loop H-D Delphi ECM will maintain the fuel mixture at the 14.6:1 AFR it came from the factory without any ECM remapping. (Excluding cold starts at 12:1, and WOT at about 12.5:1)
This mapping has a narrow window for changes, (also related to the narrowband sensors they use) and works mostly in the middle 40% range, where most of us ride. After changing mufflers and even the air intake, on 2010-up models, the bike will still return the parameters to 14.6:1, but there have been cases where the a/f ratios have been as high as 15:1. This is a recipe for heat and disaster.... This is why most people will recommend a fuel management system, to add more fuel not JUST for performance, but to bring engine temps (cylinder/head) down.
It's a tad more complicated then this, but simplified, this is it.
My point being: I see a rider In Brewton, Alabama. He's close to sea level. A bike can run leanest at sea level where as a bike at higher elevations will run richer. With his location AND pipe mod....perhaps he's at the end of the limit, once his bike is warm and in closed loop, due to another reason.
There's 3 key sensors on the bike that take readings (other then the O2 sensors which would be 4) and maybe one of them is slow, or not reading correctly. A simple scan test could determine this.
IAT sensor: (Intake Air Temp) Reads the temps of the air entering the engine. Warm/hot air contains less oxygen then cooler or cold air. Living in a hot climate and having a failed/slow sensor can cause a lean condition. Lean equals less power...
MAP sensor: (Manifold Absolute Temp) This sensor sends signals to the ECU regarding intake manifold pressure and ambient barometric pressure. Intake pressure tells the ECU information about speed and load on the engine. Ambient pressure is in regards to elevation. Both effect a/f ratios........
ET sensor: (engine temp) Senses heat in the front head and tells the ECU if the engine is at full temp or not, and when to go into closed loop, from open loop.
Even a slow or doggy O2 sensor can be an issue.
To clear the air: I'm saying the low end loss (if it exists) isn't due to the small pipe mod that he made, as was claimed. ESPECIALLY with an ECU that senses changes, and readjusts for losses, back to the original parameters of 14.6:1 air fuel ratio.
If the ECU corrects the problem, there is no problem, and no change according to the ECU and performance remains the same. That's how and why it was designed. (Well...actually to maintain a consistent a/f ratio for EPA standards)
If the ECU or sensors aren't doing their jobs, then and only then, will a change be noticed, whether it's on a Dyno, or on the road.
Last edited by Osco; 05-30-2011 at 05:35 PM.
#3
05-30-2011, 05:38 PM
From anither member,,,
Plug Reading 101
--------------------------------------------------------------------------------
I have been posting this whenever someone needed help tuning, and it was just suggested that I start a thread with this so that I won't have to repost every time someone needs it.
This method comes from my long term friendship with Brad Urban who until he passed away a few years ago was one of the leading carb builders in the world (The Carburetor Shop), and for a period of about 6 years I went with Brad to one of the different short tracks in Southern California every weekend durring racing season to tune his carbs. For that 6 years his carbs were on cars that heald the track record at every track in Southern California for the entire period, and three of four cars in the trophy dashes were routinely his too. This 6 year time period started while Ascot was still running and continued past the time that Ascot was closed down. Brad was featured in Hot Rod, Super Chevy, and Circle Track regularly, and the world of racing lost a lot with his passing. It is my aim to keep his method alive, because I am not getting any younger myself.
Plug Reading 101
First off, forget everything you think you know from reading repair manuals because that only works on engines with old used plugs and engine problems that are easy for the average person to see on the plug without any special training.
Plugs can be read with as little as two laps on them at the track.
· Start with new, or extremely clean recently new plugs.
· Best readings are taken by running the vehicle at sustained speeds in the range that you are checking, IE: “Wide Open”, Mid Range”, “At or near Idle”, then disengaging the clutch, killing the engine cleanly, and coasting to a stop.
· Overall readings can still be taken without a clean kill and stop, even without new plugs. This is still very accurate, and one of the best tune up tools you have. Just make sure that you have good plugs and by keeping an eye on them as you make changes you can read the effect that the changes made. This just requires a mental track record or a written one.
Where to read them.
· The porcelain is used for reading plug heat range, and timing only. Never try to read fuel mixture off the porcelain.
· The inner wall of the metal shell extending down to where that meets the porcelain is where you read the mixture.
· Engine problems such as oil consumption, etc., are read by going back to your manual. We are only concerned with a good sound engine for fine tuning purposes.
How to read them.
· Timing that has too much advance will show as black flecks on the porcelain. These are flecks of aluminum off the piston due to detonation. Even a good running engine will show signs of minor detonation, but keep an eye on those flecks and if they get bigger and more of them it’s time to look seriously at the timing.
· To determine heat range of your plugs look at the porcelain as it starts to take color. If the porcelain is white to a light tan, the heat range of the plug is right. Remember we are talking a couple of laps so it doesn’t have much time to take color which is why white is acceptable. If it starts looking gray or black possibly even a bit wet looking, the plug is too cold. The more black it is and the more it is wet, the further to the cold side it is. If the plug is dark tan or worse yet getting a burnt black look to it with blisters on the porcelain, then it is too hot a plug. Note the difference between a cold black and a burnt black at the two extremes. They are not the same black by any means. Fuel deposits on older plugs flake off, so don’t confuse that with blistering.
· For reading mixture, read the metal inner wall ONLY.
· The upper ring around the electrode area (as you hold the plug electrode up facing you) is where you read the idle mixture. Correct reading is MEDIUM GRAY. Light gray to whitish gray is lean, dark gray to black is rich, with powdery black being richer yet, then after that it starts to get wet and the black gets flushed off like it was rinsed with gas. (You will see some of this on the intake valve side of the plug and that is not a concern if the color is correct otherwise).
· The lower ring where it meets the porcelain way down inside (you need a magnifying glass and good lighting to see clearly down to the bottom), is where you read wide open throttle. Color readings are the same for all ranges except that the wet flushed off look is only going to be showing at the idle portion of the plug.
· The mid range is everywhere in between that top ring and the bottom ring. Color is again read the same.
To bring this into perspective for the Sportster.
· Stock timing will be acceptable unless it’s broken. I see some specs on mine, so some over advance seems normal, just keep an eye on it over time looking for changes.
· Stock heat range of plug will be good through stage 1 and possibly stage 2. If the compression gets raised too much then you may need to drop to a colder plug, and that will become evident if the porcelain gets dark tan to black and blistered.
· Idle reading will be a function of the mixture screw, and the pilot jet. If that upper ring is light tan or whitish, then open up that idle screw until the engine sounds right (about three turns to three and a quarter out for stage 1). Only consider upping the pilot jet if you can not get it right with the mixture screw.
· Mid range will be a function of the needle, the needle position, and close to idle the pilot jet will effect it too. The Main jet will also effect the mid range, but at the same time it will effect the wide open throttle setting too.
· Wide Open Throttle is mostly the Main jet.
I always work on idle and WOT first. Once I get those in range I take it for a good ride and pull the plugs to double check those two extremes and start working on the mid range which takes more patience.
To fine tune it in any range, do the clean kill in the range in question, then read that section of the plug.
As long as the plugs are reading nice in all the ranges then you can periodically look at them and see that everything is still good. I always take compression and read the plugs every time I do a tune up and I change the plugs out for every tune up too (5000 miles)
__________________
--------------------------------------------------------------------------------
I have been posting this whenever someone needed help tuning, and it was just suggested that I start a thread with this so that I won't have to repost every time someone needs it.
This method comes from my long term friendship with Brad Urban who until he passed away a few years ago was one of the leading carb builders in the world (The Carburetor Shop), and for a period of about 6 years I went with Brad to one of the different short tracks in Southern California every weekend durring racing season to tune his carbs. For that 6 years his carbs were on cars that heald the track record at every track in Southern California for the entire period, and three of four cars in the trophy dashes were routinely his too. This 6 year time period started while Ascot was still running and continued past the time that Ascot was closed down. Brad was featured in Hot Rod, Super Chevy, and Circle Track regularly, and the world of racing lost a lot with his passing. It is my aim to keep his method alive, because I am not getting any younger myself.
Plug Reading 101
First off, forget everything you think you know from reading repair manuals because that only works on engines with old used plugs and engine problems that are easy for the average person to see on the plug without any special training.
Plugs can be read with as little as two laps on them at the track.
· Start with new, or extremely clean recently new plugs.
· Best readings are taken by running the vehicle at sustained speeds in the range that you are checking, IE: “Wide Open”, Mid Range”, “At or near Idle”, then disengaging the clutch, killing the engine cleanly, and coasting to a stop.
· Overall readings can still be taken without a clean kill and stop, even without new plugs. This is still very accurate, and one of the best tune up tools you have. Just make sure that you have good plugs and by keeping an eye on them as you make changes you can read the effect that the changes made. This just requires a mental track record or a written one.
Where to read them.
· The porcelain is used for reading plug heat range, and timing only. Never try to read fuel mixture off the porcelain.
· The inner wall of the metal shell extending down to where that meets the porcelain is where you read the mixture.
· Engine problems such as oil consumption, etc., are read by going back to your manual. We are only concerned with a good sound engine for fine tuning purposes.
How to read them.
· Timing that has too much advance will show as black flecks on the porcelain. These are flecks of aluminum off the piston due to detonation. Even a good running engine will show signs of minor detonation, but keep an eye on those flecks and if they get bigger and more of them it’s time to look seriously at the timing.
· To determine heat range of your plugs look at the porcelain as it starts to take color. If the porcelain is white to a light tan, the heat range of the plug is right. Remember we are talking a couple of laps so it doesn’t have much time to take color which is why white is acceptable. If it starts looking gray or black possibly even a bit wet looking, the plug is too cold. The more black it is and the more it is wet, the further to the cold side it is. If the plug is dark tan or worse yet getting a burnt black look to it with blisters on the porcelain, then it is too hot a plug. Note the difference between a cold black and a burnt black at the two extremes. They are not the same black by any means. Fuel deposits on older plugs flake off, so don’t confuse that with blistering.
· For reading mixture, read the metal inner wall ONLY.
· The upper ring around the electrode area (as you hold the plug electrode up facing you) is where you read the idle mixture. Correct reading is MEDIUM GRAY. Light gray to whitish gray is lean, dark gray to black is rich, with powdery black being richer yet, then after that it starts to get wet and the black gets flushed off like it was rinsed with gas. (You will see some of this on the intake valve side of the plug and that is not a concern if the color is correct otherwise).
· The lower ring where it meets the porcelain way down inside (you need a magnifying glass and good lighting to see clearly down to the bottom), is where you read wide open throttle. Color readings are the same for all ranges except that the wet flushed off look is only going to be showing at the idle portion of the plug.
· The mid range is everywhere in between that top ring and the bottom ring. Color is again read the same.
To bring this into perspective for the Sportster.
· Stock timing will be acceptable unless it’s broken. I see some specs on mine, so some over advance seems normal, just keep an eye on it over time looking for changes.
· Stock heat range of plug will be good through stage 1 and possibly stage 2. If the compression gets raised too much then you may need to drop to a colder plug, and that will become evident if the porcelain gets dark tan to black and blistered.
· Idle reading will be a function of the mixture screw, and the pilot jet. If that upper ring is light tan or whitish, then open up that idle screw until the engine sounds right (about three turns to three and a quarter out for stage 1). Only consider upping the pilot jet if you can not get it right with the mixture screw.
· Mid range will be a function of the needle, the needle position, and close to idle the pilot jet will effect it too. The Main jet will also effect the mid range, but at the same time it will effect the wide open throttle setting too.
· Wide Open Throttle is mostly the Main jet.
I always work on idle and WOT first. Once I get those in range I take it for a good ride and pull the plugs to double check those two extremes and start working on the mid range which takes more patience.
To fine tune it in any range, do the clean kill in the range in question, then read that section of the plug.
As long as the plugs are reading nice in all the ranges then you can periodically look at them and see that everything is still good. I always take compression and read the plugs every time I do a tune up and I change the plugs out for every tune up too (5000 miles)
__________________
#4
05-30-2011, 07:06 PM
Outstanding HDF Member
#5
05-30-2011, 08:24 PM
Road Captain
#6
05-31-2011, 06:47 AM
#7
05-31-2011, 06:54 AM
these are the people i think this thread pertains to. no doubt someone with less experience, who is eager to learn, will soak up osco's posts and still crave more.
. 