My CFR Experience
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Cruiser
Joined: Oct 2009
Posts: 109
Likes: 0
My CFR Experience
After reading many posts about these pipes having un-tunable decal pop, low end stumble and power loss etc, etc, I tried them anyway because I love the look and sound of them.
I have a stock 09 streetglide with a stage 1 AC.
After installing them I had a slight decal pop, but not much.
I spent a few hours doing some tuning runs using my SEPST to dial in the VE tables and ignition timing.
Bike runs great, has no decal pop or loss of low end performance, runs and sounds great. Guys I ride with comment on how nice they sound and are not obnoxious to ride behind at all.
I am totally satisfied with them.
The other day I was riding home in the center lane of a 3 lane road. A cop car pulls up behind me, backs off, pulls up again then changes lanes back and forth on each side of me. I thought "here we go, get ready for some grief". I pull up to a red light and he pulls along side me and puts down his window.
"What pipes are you running on that thing?"
"CFR's"
"They sound awesome buddy, one of the nicest pipes I have ever heard. I had to hear them from all sides. Have a nice day".
"Thanks, I really love them".
He turns right and drives away, and I giver as I pull away from the light and head home!
That was a surprise.
Anyone sitting on the fence should give them a try.
.
I have a stock 09 streetglide with a stage 1 AC.
After installing them I had a slight decal pop, but not much.
I spent a few hours doing some tuning runs using my SEPST to dial in the VE tables and ignition timing.
Bike runs great, has no decal pop or loss of low end performance, runs and sounds great. Guys I ride with comment on how nice they sound and are not obnoxious to ride behind at all.
I am totally satisfied with them.
The other day I was riding home in the center lane of a 3 lane road. A cop car pulls up behind me, backs off, pulls up again then changes lanes back and forth on each side of me. I thought "here we go, get ready for some grief". I pull up to a red light and he pulls along side me and puts down his window.
"What pipes are you running on that thing?"
"CFR's"
"They sound awesome buddy, one of the nicest pipes I have ever heard. I had to hear them from all sides. Have a nice day".
"Thanks, I really love them".
He turns right and drives away, and I giver as I pull away from the light and head home!
That was a surprise.
Anyone sitting on the fence should give them a try.
.
Outstanding HDF Member
Joined: May 2008
Posts: 3,078
Likes: 0
From: Iowa
After reading many posts about these pipes having un-tunable decal pop, low end stumble and power loss etc, etc, I tried them anyway because I love the look and sound of them.
I have a stock 09 streetglide with a stage 1 AC.
After installing them I had a slight decal pop, but not much.
I spent a few hours doing some tuning runs using my SEPST to dial in the VE tables and ignition timing.
Bike runs great, has no decal pop or loss of low end performance, runs and sounds great. Guys I ride with comment on how nice they sound and are not obnoxious to ride behind at all.
I am totally satisfied with them.
The other day I was riding home in the center lane of a 3 lane road. A cop car pulls up behind me, backs off, pulls up again then changes lanes back and forth on each side of me. I thought "here we go, get ready for some grief". I pull up to a red light and he pulls along side me and puts down his window.
"What pipes are you running on that thing?"
"CFR's"
"They sound awesome buddy, one of the nicest pipes I have ever heard. I had to hear them from all sides. Have a nice day".
"Thanks, I really love them".
He turns right and drives away, and I giver as I pull away from the light and head home!
That was a surprise.
Anyone sitting on the fence should give them a try.
.
I have a stock 09 streetglide with a stage 1 AC.
After installing them I had a slight decal pop, but not much.
I spent a few hours doing some tuning runs using my SEPST to dial in the VE tables and ignition timing.
Bike runs great, has no decal pop or loss of low end performance, runs and sounds great. Guys I ride with comment on how nice they sound and are not obnoxious to ride behind at all.
I am totally satisfied with them.
The other day I was riding home in the center lane of a 3 lane road. A cop car pulls up behind me, backs off, pulls up again then changes lanes back and forth on each side of me. I thought "here we go, get ready for some grief". I pull up to a red light and he pulls along side me and puts down his window.
"What pipes are you running on that thing?"
"CFR's"
"They sound awesome buddy, one of the nicest pipes I have ever heard. I had to hear them from all sides. Have a nice day".
"Thanks, I really love them".
He turns right and drives away, and I giver as I pull away from the light and head home!
That was a surprise.
Anyone sitting on the fence should give them a try.
.
If you are like many casual riders that just love the sound and don't mind the torque dips, pull the trigger. I think they sound great but I love the 2-1 performance.
Road Captain
Joined: Oct 2007
Posts: 568
Likes: 147
From: Georgia
I have CFR's on true duals on my bike and they pop a fair amount. I had Fuel Moto try to adjust the map on my Power Vision but still get frequent popping on decel and upshift. Annoying to the point of contemplating switching to something else.
Outstanding HDF Member
Joined: May 2008
Posts: 3,078
Likes: 0
From: Iowa
That sucks!
Stellar HDF Member
Joined: Nov 2010
Posts: 2,576
Likes: 456
From: Maryland
Use to have the CFR's on both my SG which I'm currently redoing and my CVO Ultra (sold). I didn't experience the decel popping that you are experiencing. But I was also running the Thundermax Autotuner which could be the difference. CFR's from what I understood before I bought them were always a mother to get tuned.
Outstanding HDF Member
Joined: Jun 2011
Posts: 2,023
Likes: 6
From: New Jersey
I grabbed this article several years ago, when I had my Yamaha Road Star "Harley Killer" (only kidding about the "Harley Killer" part, guys):
Mikuni on the subject:
"BACKFIRING IN EXHAUST SYSTEM when the throttle is closed,especially noticeable from high rpm, is not caused by lean mixtures, although lean mixtures can contribute to its intensity. This is a normal condition when using high performance exhaust systems."
A post on the VTXO forum by Trapper on the subject:
Burn Baby Burn
The last thing I want to address today is the subject of deceleration backfire, or “popping”. This topic generates a lot of concern from inexperienced riders, or even from experienced guys who just hatethe noise, so lets take a look at what causes it. But first things first, lets define the issue:
Deceleration Backfire is caused by fuel burning in the exhaust manifold or header.
No ifs, ands, or buts, that’s what causes it. But the bigger question is how does gas get there in the first place, andthat’s a bit more complicated. Generally, there are a variety of ways it gets there, and a variety of things that can make the backfiring worse. But there’s a kicker, and something you should understand before we go any farther:
A motor in perfect tune will exhibitdeceleration backfiring.
Therefore, just because your motor is banging it up, doesn’t mean there’s anything wrong. And consequently:
Getting rid of the noise means de-tuning your motor.
Yup. If you’ve jut got to eliminate that popping, you’ll have to accept the fact that your motor is going to be forced to run rich to do it, and that isn’t necessarily a good thing. So lets talk about what causes the problem.
Ok, so you’re riding along at some given rpm,and suddenly you decide to decelerate, and you reduce the amount of throttle.This causes an “overrun” – that is, the motors rpm is turning faster than the fuel provided can support, so the motor begins to spool down. This causes a couple of things to happen.
First, when you close the throttle, you are also closing the throttle plates. This reduces the air and fuel flowing into the motor, and increases the vacuum (lowers the pressure). This results in less air and fuel in the cylinder during the power stroke, which in turn results ina lower pressure in the combustion chamber. Remember when I said earlier, that the A/F mix burns faster in proportion to the pressure applied? Well, when we reduce pressure this way, the mix burns slower.
This results in two things happening:
1. The lower burning fuel generates less heat, and the cooling effect of the non-burning fuel tends to “quench” the flame front, or slow it down even further. Because the mix is burning much slower, the exhaust valve can open before all the fuel is consumed, and the unburnt fuel is ejected into the exhaust.
2. The engine designers, in order to promote smoother idling and better combustion, retard the spark when the throttle is shut, and this results in the mix being lit later.
So, now we end up with unburnt fuel in theexhaust, and burning fuel being ejected into the exhaust, and bang! Backfire.
So the bottom line, is: That backfiring isperfectly normal and expected. If you’ve just got get rid of it, that’s up to you. You’re entitled to set your motor up the way you want, and your goals are your goals. But don’t refer to it as “fixing” the popping. Rather, the correct way to think of it is “de-tuning a bit to get rid of the popping”.
There are a few ways you can do this.
First, use the stock pipe. It will hide the sound, by absorbing it into mass, and masking it with the larger baffle space. Second, you can add more fuel during deceleration. This has the effect ofraising the chamber pressure slightly, which burns a little more before the exhaust valve opens.
Mikuni on the subject:
"BACKFIRING IN EXHAUST SYSTEM when the throttle is closed,especially noticeable from high rpm, is not caused by lean mixtures, although lean mixtures can contribute to its intensity. This is a normal condition when using high performance exhaust systems."
A post on the VTXO forum by Trapper on the subject:
Burn Baby Burn
The last thing I want to address today is the subject of deceleration backfire, or “popping”. This topic generates a lot of concern from inexperienced riders, or even from experienced guys who just hatethe noise, so lets take a look at what causes it. But first things first, lets define the issue:
Deceleration Backfire is caused by fuel burning in the exhaust manifold or header.
No ifs, ands, or buts, that’s what causes it. But the bigger question is how does gas get there in the first place, andthat’s a bit more complicated. Generally, there are a variety of ways it gets there, and a variety of things that can make the backfiring worse. But there’s a kicker, and something you should understand before we go any farther:
A motor in perfect tune will exhibitdeceleration backfiring.
Therefore, just because your motor is banging it up, doesn’t mean there’s anything wrong. And consequently:
Getting rid of the noise means de-tuning your motor.
Yup. If you’ve jut got to eliminate that popping, you’ll have to accept the fact that your motor is going to be forced to run rich to do it, and that isn’t necessarily a good thing. So lets talk about what causes the problem.
Ok, so you’re riding along at some given rpm,and suddenly you decide to decelerate, and you reduce the amount of throttle.This causes an “overrun” – that is, the motors rpm is turning faster than the fuel provided can support, so the motor begins to spool down. This causes a couple of things to happen.
First, when you close the throttle, you are also closing the throttle plates. This reduces the air and fuel flowing into the motor, and increases the vacuum (lowers the pressure). This results in less air and fuel in the cylinder during the power stroke, which in turn results ina lower pressure in the combustion chamber. Remember when I said earlier, that the A/F mix burns faster in proportion to the pressure applied? Well, when we reduce pressure this way, the mix burns slower.
This results in two things happening:
1. The lower burning fuel generates less heat, and the cooling effect of the non-burning fuel tends to “quench” the flame front, or slow it down even further. Because the mix is burning much slower, the exhaust valve can open before all the fuel is consumed, and the unburnt fuel is ejected into the exhaust.
2. The engine designers, in order to promote smoother idling and better combustion, retard the spark when the throttle is shut, and this results in the mix being lit later.
So, now we end up with unburnt fuel in theexhaust, and burning fuel being ejected into the exhaust, and bang! Backfire.
So the bottom line, is: That backfiring isperfectly normal and expected. If you’ve just got get rid of it, that’s up to you. You’re entitled to set your motor up the way you want, and your goals are your goals. But don’t refer to it as “fixing” the popping. Rather, the correct way to think of it is “de-tuning a bit to get rid of the popping”.
There are a few ways you can do this.
First, use the stock pipe. It will hide the sound, by absorbing it into mass, and masking it with the larger baffle space. Second, you can add more fuel during deceleration. This has the effect ofraising the chamber pressure slightly, which burns a little more before the exhaust valve opens.
Last edited by FenderGuy53; Oct 4, 2013 at 10:05 AM.
Road Master
Joined: Jun 2013
Posts: 1,043
Likes: 25
From: Malaysia
I got the CFRs and slipped it on the minute I got it.No tuner,stock header and AC.I had no decel pops.in a weeks time I went stage 1,AC,SESPT and the V&H powerduals.The sound just transformed and I love it.The idle is really nice,you can tell the engine is much happier,no decel pops whatsoever.I haven't done a dyno run but my **** tells me it much preppier and responsive.The best part of all is that I just sound a lot different from the rest.I like to call it the new generation Harley sound.
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Outstanding HDF Member
Joined: May 2008
Posts: 3,078
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From: Iowa
2-1 for sure!
Cruiser
Joined: Sep 2012
Posts: 185
Likes: 0
From: Mo.
I grabbed this article several years ago, when I had my Yamaha Road Star "Harley Killer" (only kidding about the "Harley Killer" part, guys):
Mikuni on the subject:
"BACKFIRING IN EXHAUST SYSTEM when the throttle is closed,especially noticeable from high rpm, is not caused by lean mixtures, although lean mixtures can contribute to its intensity. This is a normal condition when using high performance exhaust systems."
A post on the VTXO forum by Trapper on the subject:
Burn Baby Burn
The last thing I want to address today is the subject of deceleration backfire, or popping. This topic generates a lot of concern from inexperienced riders, or even from experienced guys who just hatethe noise, so lets take a look at what causes it. But first things first, lets define the issue:
Deceleration Backfire is caused by fuel burning in the exhaust manifold or header.
No ifs, ands, or buts, thats what causes it. But the bigger question is how does gas get there in the first place, andthats a bit more complicated. Generally, there are a variety of ways it gets there, and a variety of things that can make the backfiring worse. But theres a kicker, and something you should understand before we go any farther:
A motor in perfect tune will exhibitdeceleration backfiring.
Therefore, just because your motor is banging it up, doesnt mean theres anything wrong. And consequently:
Getting rid of the noise means de-tuning your motor.
Yup. If youve jut got to eliminate that popping, youll have to accept the fact that your motor is going to be forced to run rich to do it, and that isnt necessarily a good thing. So lets talk about what causes the problem.
Ok, so youre riding along at some given rpm,and suddenly you decide to decelerate, and you reduce the amount of throttle.This causes an overrun that is, the motors rpm is turning faster than the fuel provided can support, so the motor begins to spool down. This causes a couple of things to happen.
First, when you close the throttle, you are also closing the throttle plates. This reduces the air and fuel flowing into the motor, and increases the vacuum (lowers the pressure). This results in less air and fuel in the cylinder during the power stroke, which in turn results ina lower pressure in the combustion chamber. Remember when I said earlier, that the A/F mix burns faster in proportion to the pressure applied? Well, when we reduce pressure this way, the mix burns slower.
This results in two things happening:
1. The lower burning fuel generates less heat, and the cooling effect of the non-burning fuel tends to quench the flame front, or slow it down even further. Because the mix is burning much slower, the exhaust valve can open before all the fuel is consumed, and the unburnt fuel is ejected into the exhaust.
2. The engine designers, in order to promote smoother idling and better combustion, retard the spark when the throttle is shut, and this results in the mix being lit later.
So, now we end up with unburnt fuel in theexhaust, and burning fuel being ejected into the exhaust, and bang! Backfire.
So the bottom line, is: That backfiring isperfectly normal and expected. If youve just got get rid of it, thats up to you. Youre entitled to set your motor up the way you want, and your goals are your goals. But dont refer to it as fixing the popping. Rather, the correct way to think of it is de-tuning a bit to get rid of the popping.
There are a few ways you can do this.
First, use the stock pipe. It will hide the sound, by absorbing it into mass, and masking it with the larger baffle space. Second, you can add more fuel during deceleration. This has the effect ofraising the chamber pressure slightly, which burns a little more before the exhaust valve opens.
Mikuni on the subject:
"BACKFIRING IN EXHAUST SYSTEM when the throttle is closed,especially noticeable from high rpm, is not caused by lean mixtures, although lean mixtures can contribute to its intensity. This is a normal condition when using high performance exhaust systems."
A post on the VTXO forum by Trapper on the subject:
Burn Baby Burn
The last thing I want to address today is the subject of deceleration backfire, or popping. This topic generates a lot of concern from inexperienced riders, or even from experienced guys who just hatethe noise, so lets take a look at what causes it. But first things first, lets define the issue:
Deceleration Backfire is caused by fuel burning in the exhaust manifold or header.
No ifs, ands, or buts, thats what causes it. But the bigger question is how does gas get there in the first place, andthats a bit more complicated. Generally, there are a variety of ways it gets there, and a variety of things that can make the backfiring worse. But theres a kicker, and something you should understand before we go any farther:
A motor in perfect tune will exhibitdeceleration backfiring.
Therefore, just because your motor is banging it up, doesnt mean theres anything wrong. And consequently:
Getting rid of the noise means de-tuning your motor.
Yup. If youve jut got to eliminate that popping, youll have to accept the fact that your motor is going to be forced to run rich to do it, and that isnt necessarily a good thing. So lets talk about what causes the problem.
Ok, so youre riding along at some given rpm,and suddenly you decide to decelerate, and you reduce the amount of throttle.This causes an overrun that is, the motors rpm is turning faster than the fuel provided can support, so the motor begins to spool down. This causes a couple of things to happen.
First, when you close the throttle, you are also closing the throttle plates. This reduces the air and fuel flowing into the motor, and increases the vacuum (lowers the pressure). This results in less air and fuel in the cylinder during the power stroke, which in turn results ina lower pressure in the combustion chamber. Remember when I said earlier, that the A/F mix burns faster in proportion to the pressure applied? Well, when we reduce pressure this way, the mix burns slower.
This results in two things happening:
1. The lower burning fuel generates less heat, and the cooling effect of the non-burning fuel tends to quench the flame front, or slow it down even further. Because the mix is burning much slower, the exhaust valve can open before all the fuel is consumed, and the unburnt fuel is ejected into the exhaust.
2. The engine designers, in order to promote smoother idling and better combustion, retard the spark when the throttle is shut, and this results in the mix being lit later.
So, now we end up with unburnt fuel in theexhaust, and burning fuel being ejected into the exhaust, and bang! Backfire.
So the bottom line, is: That backfiring isperfectly normal and expected. If youve just got get rid of it, thats up to you. Youre entitled to set your motor up the way you want, and your goals are your goals. But dont refer to it as fixing the popping. Rather, the correct way to think of it is de-tuning a bit to get rid of the popping.
There are a few ways you can do this.
First, use the stock pipe. It will hide the sound, by absorbing it into mass, and masking it with the larger baffle space. Second, you can add more fuel during deceleration. This has the effect ofraising the chamber pressure slightly, which burns a little more before the exhaust valve opens.
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