why does 2 into 1 exhaust giver better performance?
Outstanding HDF Member
Joined: Jun 2011
Posts: 3,036
Likes: 19
From: Savage, MN
This! +1
Not seen too much behind the claims made here. Here's a few thunks on the subject...
For big engines you need big fat exhausts for best higher RPM performance. Optimally you want a can 10 times bigger than the cylinder size. If you have a 2-2 skinny exhaust system then each cylinder has its own small skinny exhaust. However, a 2-1 has a single fat can shared by the cylinders (one using it at a time) in the space of the two mufflers of a 2-2 system. The touring models achieve good results with large exhausts cross-linked to give an even bigger exhaust as seen by each cylinder.
Some 2-1 systems, like Supertrapp, offer the feature of tuning the exhaust with adjustable baffles. This gets over the one-size-fits-all issue of 2-2 systems.
Open, straight 2-2 systems can out-perform 2-1 systems at higher RPMs, at the risk of loss of lower speed performance.
Most exhaust systems are designed firstly for looks/noise and only secondly for performance. Those with this reversed tend to look relatively ugly and/or like racing cans. This is true whether its a 2-2, 2-1-2 or 2-1 system, so it's definitely not possible to say something as simple as, "Its a 2-1 system so performs better".
For big engines you need big fat exhausts for best higher RPM performance. Optimally you want a can 10 times bigger than the cylinder size. If you have a 2-2 skinny exhaust system then each cylinder has its own small skinny exhaust. However, a 2-1 has a single fat can shared by the cylinders (one using it at a time) in the space of the two mufflers of a 2-2 system. The touring models achieve good results with large exhausts cross-linked to give an even bigger exhaust as seen by each cylinder.
Some 2-1 systems, like Supertrapp, offer the feature of tuning the exhaust with adjustable baffles. This gets over the one-size-fits-all issue of 2-2 systems.
Open, straight 2-2 systems can out-perform 2-1 systems at higher RPMs, at the risk of loss of lower speed performance.
Most exhaust systems are designed firstly for looks/noise and only secondly for performance. Those with this reversed tend to look relatively ugly and/or like racing cans. This is true whether its a 2-2, 2-1-2 or 2-1 system, so it's definitely not possible to say something as simple as, "Its a 2-1 system so performs better".
Elite HDF Member
Joined: Jul 2007
Posts: 4,749
Likes: 16
From: sand mountain Alabama
This was a most interesting and amazing read.
The thing is if you are going to be on the track most of the time or cruising different exhausts are the form.
Personally I prefer 2 into 2. I may hit it from time to time but I don't hit the track. I did not get it for that.
For my type of riding the 2 into 1 doesn't help that much. Yes I tried the 2 into 1, Road Rage. Liked the look and sound with the extra tq.. However, our bike is producing over 120 hp so it just didn't matter to us. The V&H big radius sounded much better and we can still smoke anything on the mountain.
Go to bike night, check out the bikes, listen to different exhaust, and talk to the guys/gals about them. Then make your own decision.
Wheat sounds good and looks good to me may not be what you like. You are not going to stay on the track any way or are you going racing at every corner or straight a way.
That is how I see it any way.
just my thoughts
dd
The thing is if you are going to be on the track most of the time or cruising different exhausts are the form.
Personally I prefer 2 into 2. I may hit it from time to time but I don't hit the track. I did not get it for that.
For my type of riding the 2 into 1 doesn't help that much. Yes I tried the 2 into 1, Road Rage. Liked the look and sound with the extra tq.. However, our bike is producing over 120 hp so it just didn't matter to us. The V&H big radius sounded much better and we can still smoke anything on the mountain.
Go to bike night, check out the bikes, listen to different exhaust, and talk to the guys/gals about them. Then make your own decision.
Wheat sounds good and looks good to me may not be what you like. You are not going to stay on the track any way or are you going racing at every corner or straight a way.
That is how I see it any way.
just my thoughts
dd
Advanced
Joined: May 2014
Posts: 74
Likes: 1
From: NJ
Lol 😂
3rd Gear
Joined: Nov 2019
Posts: 6
Likes: 0
From: California
Again, in an all-out drag race, you will only see the upper rpm range. That was my point. The mid-range hp and torque don't mean anything in a drag race. So unless you are putting a rev-limit of 4500 rpms on both bikes, I don't see how the 2-1 is gonna run 3+ bike lengths on a 2-2. Pretty sure most Stage 1 bikes, at least my PowerVision, is set to 6200 rpms.
As for scooting around town, I am not disagreeing with you on the mid-range hp and torque being usable but the difference is nothing to lose sleep over, especially on a stage 1 bike.
I don't need to post this for the engine guys. And I purposely left out built motors so let's not twist what I said. There is only 1 known way to settle this.... we need to run'em at the track.
As for scooting around town, I am not disagreeing with you on the mid-range hp and torque being usable but the difference is nothing to lose sleep over, especially on a stage 1 bike.
I don't need to post this for the engine guys. And I purposely left out built motors so let's not twist what I said. There is only 1 known way to settle this.... we need to run'em at the track.
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