Torque cones on Samsons?
Thread Starter
|
Tourer
Joined: Feb 2011
Posts: 339
Likes: 0
From: Central Cal
Torque cones on Samsons?
OK, so I have read as much as I can find and it seems like there is no clear answer. I am hoping some of you guys can shed some light on this. (hopefully some of you that run samsons without baffles, are you running these, if not, why?)
I have a 2004 w/ fuel injection. I am going to install my new Samson 33 inch longtails with no baffles as soon as my tins and bars are on. I have a Ness Big Sucker Stage 1. I am going to be running a Fuelpak.
With the above set-up, should I use torque cones? If so, why and what kind? (some are super cheap, under $10; http://www.kcint2.com/product/60-TC-...T-HARLEYS.html )
If I don't need them, why?
Any help would be great. I am ordering a few things to finish this bike up and would like to throw these on the order if needed.
I have a 2004 w/ fuel injection. I am going to install my new Samson 33 inch longtails with no baffles as soon as my tins and bars are on. I have a Ness Big Sucker Stage 1. I am going to be running a Fuelpak.
With the above set-up, should I use torque cones? If so, why and what kind? (some are super cheap, under $10; http://www.kcint2.com/product/60-TC-...T-HARLEYS.html )
If I don't need them, why?
Any help would be great. I am ordering a few things to finish this bike up and would like to throw these on the order if needed.
Former Sponsor
Joined: Jan 2009
Posts: 19,364
Likes: 40
From: Los Angeles, CA
I ahve run my pipes both ways. I felt no distinguishable differece with the torque cones and am not running them at this point in time. The philosopy with torque cones is that they will keep unburned exhaust gasses from getting sucked back into the head. But, they are cheap and it can't hurt. I sold the ones I had or I would have put them back in.
Drew
Drew
Road Captain
Joined: Mar 2008
Posts: 601
Likes: 6
From: Aruba
My opinion, and we know what opinions are like, is that torque cones are a waste of money. You can get the same effect with the lollipop trick plus you aren't creating disturbance with your exhaust trying to exit the combustion chambers right at the exit point. The people selling torque cones will usually give the example of an open garden hose and then putting a nozzle or your thumb over it and see how much faster the water exits. Problem is that a torque cone isn't at the end of the pipe, it's at the beginning. This would be like restricting the water flow of the garden hose at the spigot. How much faster will the water be flowing through the hose now?
Drag pipes are made for drag racing where your revs are always above the 2000-3500 rpm flat spot created by the drag pipes. You're better off getting decent mufflers and pipes that will perform well in the RPM range that you ride in.
That said, I like the sound of open pipes as much as the next person if not more. Big City Thunder makes a "baffle" that combines the lollipop trick with a narrowing and expanding of the pipe which fits near the end. You get a deeper sound than an open pipe and better performance than open pipes and they are just as loud. Most people who have them say they love them. I myself have not tried them but I have put lollipops in a Sportster before with better results than without.
Drag pipes are made for drag racing where your revs are always above the 2000-3500 rpm flat spot created by the drag pipes. You're better off getting decent mufflers and pipes that will perform well in the RPM range that you ride in.
That said, I like the sound of open pipes as much as the next person if not more. Big City Thunder makes a "baffle" that combines the lollipop trick with a narrowing and expanding of the pipe which fits near the end. You get a deeper sound than an open pipe and better performance than open pipes and they are just as loud. Most people who have them say they love them. I myself have not tried them but I have put lollipops in a Sportster before with better results than without.
Former Sponsor
Joined: Jan 2009
Posts: 19,364
Likes: 40
From: Los Angeles, CA
You have to consider the point that was brought up about the flow of the exhaust out of the head. I am not sure what kind of affect that will really have on them. You can always pop them out and do a comparison and write up for everyone here.
Drew
Drew
Thread Starter
|
Tourer
Joined: Feb 2011
Posts: 339
Likes: 0
From: Central Cal
Ha ha... as soon as this bike is back on the road I am NEVER going to mess with it again!
This has been a huge pain in the a$$. I just want to ride!
This has been a huge pain in the a$$. I just want to ride!
Trending Topics
Cruiser
Joined: Jul 2011
Posts: 210
Likes: 1
From: Pacific Northwest
Plain and simple, the purpose of using torque cones is to add some back pressure. The amount of back pressure they actually produce is debatable to say the least.
There is always a small amount of trace exhaust gasses left behind in the combustion chamber when the exhaust valve closes. The more back pressure, the more trace gasses that are left behind. One thing trace gasses have very little of is O2 (if the engine is running properly).
When you put on pipes that breath better, you have less trace exhaust gasses left in the chamber so the resulting fuel/air mixture that compresses will be a little higher in O2 saturation. Because of this, a carbureted motor might need to be jetted a little richer or a CFI motor might need to be mapped a little richer (unless it has O2 sensors, in which case it will adjust itself).
Some people use torque cones because they were told that they wouldn't need to re-jet if they used them. It may or may not be true in any given application. The best thing to do is inspect the spark plugs to determine if you are running too lean (or too rich).
The most important thing about back pressure is that it is the same on both (or all) cylinders for maximum efficiency. Tuned headers will have the same back pressure on both/all cylinders. With different length pipes, there should be a cross-over to maintain equal back pressure.
There is always a small amount of trace exhaust gasses left behind in the combustion chamber when the exhaust valve closes. The more back pressure, the more trace gasses that are left behind. One thing trace gasses have very little of is O2 (if the engine is running properly).
When you put on pipes that breath better, you have less trace exhaust gasses left in the chamber so the resulting fuel/air mixture that compresses will be a little higher in O2 saturation. Because of this, a carbureted motor might need to be jetted a little richer or a CFI motor might need to be mapped a little richer (unless it has O2 sensors, in which case it will adjust itself).
Some people use torque cones because they were told that they wouldn't need to re-jet if they used them. It may or may not be true in any given application. The best thing to do is inspect the spark plugs to determine if you are running too lean (or too rich).
The most important thing about back pressure is that it is the same on both (or all) cylinders for maximum efficiency. Tuned headers will have the same back pressure on both/all cylinders. With different length pipes, there should be a cross-over to maintain equal back pressure.
Last edited by pnw_hd_rider; Aug 22, 2011 at 04:21 PM.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Road Captain
Joined: Mar 2008
Posts: 601
Likes: 6
From: Aruba
The big question is do the torque cones actually have any effect on the reversion pulse or not.
Cruiser
Joined: Jul 2011
Posts: 210
Likes: 1
From: Pacific Northwest
Actually what The Dr was referring to was the torque cone's supposed ability to be able to stop reversion or pulse from disrupting exhaust flow out of the cylinder thereby allowing the flow of exhaust to continue unabated out of the combustion chamber. The pulse returning to the cylinder supposedly bounces off the torque cone and reverses direction again instead of making it all the way to the exhaust valve. At the same time the exhaust velocity will help draw fresh fuel mixture in due to valve overlap. Without the torque cones, if the exhaust valve is closed when the pulse hits it, that's theoretically not a big deal as the pulse will reverse directions again and eventually dissipate. If it is opened, the pulse will continue into the combustion chamber and interfere with scavenging of burnt fuel mixture and drawing in fresh mixture.
The big question is do the torque cones actually have any effect on the reversion pulse or not.
The big question is do the torque cones actually have any effect on the reversion pulse or not.
Reducing the reverse flow pulse leads to higher O2 saturation in the final fuel/air mixture that gets compressed. More O2 saturation increases the fuel requirement for a proper burn, thus making the need to re-jet or remap when changing the exhaust to something that allows the engine to breath better.
Two strokes have reverse flow pulse at the exhaust port because they don't have exhaust valves (that;s why they have expansion chambers). There should never be reverse flow through a 4 stroke exhaust port.