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Power difference of 2 - 2 vs 2 - 1

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  • leachy
    leachy
    4 years ago
    Hi All,
    So like everyone else the Covid Virus has given me a lot more time to think and plan, probably to my detriment.

    I really like the look and sound of the 2 into 2 pipes, at the moment the bike has 2 into 1 SE muffler with SE Tuner, (Stage 1). My question is does the 2 into 2 really make that much of a difference to performance is it really that noticeable a drop. Im not out to get the limit of performance from a stock 103 engine, but at the same time I dont want it to be alot less than what it currently is. 

    Is the difference something you can really feel or is it more an academic thing you can see on dyno charts. I was looking at the Freedom Radical Radius or the V & H Big Shots, but worried about the scraping. If it was Dyno tuned properly Im hoping it will end up around the same power.

    Thanks for your thoughts from those with more experience than me.

    Leachy


  • paulybronco
    paulybronco
    4 years ago
    Quoting leachy on 17 Apr 2020 03:34 AM

    Hi All,

    So like everyone else the Covid Virus has given me a lot more time to think and plan, probably to my detriment.

    I really like the look and sound of the 2 into 2 pipes, at the moment the bike has 2 into 1 SE muffler with SE Tuner, (Stage 1). My question is does the 2 into 2 really make that much of a difference to performance is it really that noticeable a drop. Im not out to get the limit of performance from a stock 103 engine, but at the same time I dont want it to be alot less than what it currently is. 

    Is the difference something you can really feel or is it more an academic thing you can see on dyno charts. I was looking at the Freedom Radical Radius or the V & H Big Shots, but worried about the scraping. If it was Dyno tuned properly Im hoping it will end up around the same power.

    Thanks for your thoughts from those with more experience than me.

    Leachy


    On a stage 1 there is only a difference on a dyno. The seat of the pants dyno will hardly feel the difference. There is the obvious weight difference between the two
  • leachy
    leachy
    4 years ago
    Thanks Pauly,
    I wasnt sure, and at the moment I dont want to go pulling the motor apart and fitting new cams.

    I was told and read its the low and mid torque that will disappear, but no one seems to mention at what stage tune the bike is and this is effectively a stock motor.

    Are the V & H / Freedom headers a lot lighter. Im also assuming there is not cat converter so that must help to some degree of getting a little performance back.   


    FPE-HD00438.jpg
  • paulybronco
    paulybronco
    4 years ago
    Quoting leachy on 17 Apr 2020 03:48 AMedited: 17 Apr 2020 03:53 AM

    Thanks Pauly,

    I wasnt sure, and at the moment I dont want to go pulling the motor apart and fitting new cams.

    I was told and read its the low and mid torque that will disappear, but no one seems to mention at what stage tune the bike is and this is effectively a stock motor.

    Are the V & H / Freedom headers a lot lighter. Im also assuming there is not cat converter so that must help to some degree of getting a little performance back.   


    FPE-HD00438.jpg
    Leachy there is a pretty complicated formula regarding primary, tapered radius etc etc and yes there is a slight decipherable difference with a std motor. Exhausts like short shots are notorious for loss of everything other than noise to to the nature of their lengh as well as temperamental to tune. If you intend to hot rod your bike in the future then seek the advice of a decent tuner/builder and get the pipe that will ultimatly give you what you want when its done but live with the downfalls it has without the build.
    As for the cat...i cut mine out and found a few things, ran cooler, and the exhaust note was deeper. The shop that i used to go to told me that a std de catted system was a few HP down on a performance header system on a std bike. That advice saved me $600
  • leachy
    leachy
    4 years ago
    Was it hard to get the cat out?
  • paulybronco
    paulybronco
    4 years ago
    Quoting leachy on 17 Apr 2020 04:33 AM

    Was it hard to get the cat out?

    No just messy. A grinder/ dremel is all you need to chop a flap in the back, then smash the cat out and the local mufller dude welded it back up. The odd bit of stubbon cat gets blown out the back over time but easy job
  • leachy
    leachy
    4 years ago
    Quoting leachy on 17 Apr 2020 04:33 AM

    Was it hard to get the cat out?

    Quoting paulybronco on 17 Apr 2020 04:40 AM

    No just messy. A grinder/ dremel is all you need to chop a flap in the back, then smash the cat out and the local mufller dude welded it back up. The odd bit of stubbon cat gets blown out the back over time but easy job

    Do you think it would need to be remapped after that?
  • paulybronco
    paulybronco
    4 years ago
    Quoting leachy on 17 Apr 2020 04:33 AM

    Was it hard to get the cat out?

    Quoting paulybronco on 17 Apr 2020 04:40 AM

    No just messy. A grinder/ dremel is all you need to chop a flap in the back, then smash the cat out and the local mufller dude welded it back up. The odd bit of stubbon cat gets blown out the back over time but easy job

    Quoting leachy on 17 Apr 2020 04:52 AM

    Do you think it would need to be remapped after that?

    Yes. What tuner do you have
  • leachy
    leachy
    4 years ago
    I have the SE Orange Tuner and software.
  • paulybronco
    paulybronco
    4 years ago
    Quoting leachy on 17 Apr 2020 04:58 AM

    I have the SE Orange Tuner and software.

    I believe it has an autotune function...i run a power vision and the auto tune function was pretty good for the mods i did.
  • leachy
    leachy
    4 years ago
    Quoting leachy on 17 Apr 2020 04:58 AM

    I have the SE Orange Tuner and software.

    Quoting paulybronco on 17 Apr 2020 05:11 AM

    I believe it has an autotune function...i run a power vision and the auto tune function was pretty good for the mods i did.

    Yeah I believe it does, I just havn't looked into it as it runs pretty well at the moment. I just like the look and sound of the 2 -2 pipes especially the freedom ones, just not cheap.
  • paulybronco
    paulybronco
    4 years ago
    Quoting leachy on 17 Apr 2020 04:58 AM

    I have the SE Orange Tuner and software.

    Quoting paulybronco on 17 Apr 2020 05:11 AM

    I believe it has an autotune function...i run a power vision and the auto tune function was pretty good for the mods i did.

    Quoting leachy on 17 Apr 2020 05:15 AM

    Yeah I believe it does, I just havn't looked into it as it runs pretty well at the moment. I just like the look and sound of the 2 -2 pipes especially the freedom ones, just not cheap.

    Have a look see if there are any s/hand around. What are they around $600 or so new
  • Ratbob
    Ratbob
    4 years ago
    Leachy I assume you have a Lowrider, can’t think of another HD with pipes that look like 2 into 1. The Lowrider pipes are not a tuned 2 into 1 system, rather the two headers feed into the cat chamber and then into the single muffler. It is not designed as a true 2 into 1 scavenging system. If you remove the cat it simply slows down the flow of the exhaust as it enters the larger (empty) cat box wherein the gas has to be recompressed to force it out the muffler, hardly ideal. 
    Moving from my SE system on a 110 to the V&H Big Radius 2-2 I did notice a drop in tourque, the bike lost that immediate bite when hitting the throttle hard at say 2000rpm. It didn’t even seem to rev out better. I used the HD Supertuner choosing a stock tune with a few adjustments. I then changed to the V&H Big Radius 2-1 hardly a full scavenging system but that immediacy came back and it revs out smoother and just feels better to ride overall, and not so hot. Oh yeah and I can hear myself think again. As for the Freedom pipes you pictured, while I haven’t looked it up, are they the model with a balance pipe, heard they perform better than the V&H which don’t run a balance pipe.
  • fatbat
    fatbat
    4 years ago
    The radius style exhausts aren’t great performing. Compared to another crappy designed exhausts like short shots there probably isn’t a noticeable difference. Compared to a well designed 2-2 or 2-1 you will feel a difference in the seat of the pants particularly down low and in midrange where back pressure matters.  Some of the best performing systems for street are long AND have a collector or cross over pipe (and are designed with no cat). 
  • leachy
    leachy
    4 years ago
    Quoting Ratbob on 17 Apr 2020 08:10 AM

    Leachy I assume you have a Lowrider, can’t think of another HD with pipes that look like 2 into 1. The Lowrider pipes are not a tuned 2 into 1 system, rather the two headers feed into the cat chamber and then into the single muffler. It is not designed as a true 2 into 1 scavenging system. If you remove the cat it simply slows down the flow of the exhaust as it enters the larger (empty) cat box wherein the gas has to be recompressed to force it out the muffler, hardly ideal. 

    Moving from my SE system on a 110 to the V&H Big Radius 2-2 I did notice a drop in tourque, the bike lost that immediate bite when hitting the throttle hard at say 2000rpm. It didn’t even seem to rev out better. I used the HD Supertuner choosing a stock tune with a few adjustments. I then changed to the V&H Big Radius 2-1 hardly a full scavenging system but that immediacy came back and it revs out smoother and just feels better to ride overall, and not so hot. Oh yeah and I can hear myself think again. As for the Freedom pipes you pictured, while I haven’t looked it up, are they the model with a balance pipe, heard they perform better than the V&H which don’t run a balance pipe.

    Hi Ratbob, 
    Yes i do, and completely understand the exhaust system isnt tuned in anyway. I really dislike the stock SE look especially where the muffler connects, the heat shields dont really match either. 

    Cant wait to few to a few bike shows again to see and heard in person what they sound like..

    Thanks for all your input.
  • fatbat
    fatbat
    4 years ago
    What year is your low rider leachy?
  • Jay-Dee
    Jay-Dee
    4 years ago
    Quoting fatbat on 17 Apr 2020 08:11 AMedited: 17 Apr 2020 08:14 AM

    The radius style exhausts aren’t great performing. Compared to another crappy designed exhausts like short shots there probably isn’t a noticeable difference. Compared to a well designed 2-2 or 2-1 you will feel a difference in the seat of the pants particularly down low and in midrange where back pressure matters.  Some of the best performing systems for street are long AND have a collector or cross over pipe (and are designed with no cat). 

    Exhaust gas velocity/cylinder scavenging matters.
    No engine will make more power or torque at any RPM with positive pressure on top of the piston during the exhaust stroke.
  • leachy
    leachy
    4 years ago
    Quoting fatbat on 17 Apr 2020 10:15 PM

    What year is your low rider leachy?

    Its a 2016 model.
  • leachy
    leachy
    4 years ago
    Quoting fatbat on 17 Apr 2020 08:11 AMedited: 17 Apr 2020 08:14 AM

    The radius style exhausts aren’t great performing. Compared to another crappy designed exhausts like short shots there probably isn’t a noticeable difference. Compared to a well designed 2-2 or 2-1 you will feel a difference in the seat of the pants particularly down low and in midrange where back pressure matters.  Some of the best performing systems for street are long AND have a collector or cross over pipe (and are designed with no cat). 

    Quoting Jay-Dee on 18 Apr 2020 12:20 AMedited: 18 Apr 2020 12:22 AM

    Exhaust gas velocity/cylinder scavenging matters.

    No engine will make more power or torque at any RPM with positive pressure on top of the piston during the exhaust stroke.

    Yes I completely understand that but I can see how the correct tuned pipe lengths of a 2 into 1 would work and the gas flow of the first cylinder acts like a venturi or vacuum on the second cylinder and drags the exhaust out of the other pipe. I just wasn't sure how well that effect happened and like a lot of things in the real world is it that noticable.
  • tussuck
    tussuck
    4 years ago
    Quoting fatbat on 17 Apr 2020 08:11 AMedited: 17 Apr 2020 08:14 AM

    The radius style exhausts aren’t great performing. Compared to another crappy designed exhausts like short shots there probably isn’t a noticeable difference. Compared to a well designed 2-2 or 2-1 you will feel a difference in the seat of the pants particularly down low and in midrange where back pressure matters.  Some of the best performing systems for street are long AND have a collector or cross over pipe (and are designed with no cat). 

    Quoting Jay-Dee on 18 Apr 2020 12:20 AMedited: 18 Apr 2020 12:22 AM

    Exhaust gas velocity/cylinder scavenging matters.

    No engine will make more power or torque at any RPM with positive pressure on top of the piston during the exhaust stroke.

    Quoting leachy on 21 Apr 2020 08:39 PM

    Yes I completely understand that but I can see how the correct tuned pipe lengths of a 2 into 1 would work and the gas flow of the first cylinder acts like a venturi or vacuum on the second cylinder and drags the exhaust out of the other pipe. I just wasn't sure how well that effect happened and like a lot of things in the real world is it that noticable.

    I have seen modelling of this (Bub website I think).  The focus of that particular exercise was in scavenging at full throttle/peak RPM to get more fuel into an normally asperated engine so the 'power band' for want of a better word was narrowish and in the RPM range they needed (ie top end vs midrange)
    Its complicated and the end result was quite interesting in that while it does indeed work it tends to be within a certain narrow RPM band ie its not a gain across the RPM board.  And where it gives a boost in one area it has a downside of removing from another.

    Also the length of the pipes is critical as all it is si a tuned waveguide (my Radio background actually has a use!). and its the reflections of the exhaust pressure pulse creating the vacum at the exhaust port.
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