a question about torque cones and true duals.

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Apr 28, 2018 | 08:44 AM

cajun1957a

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a question about torque cones and true duals.

So we all know straight pipes rob a motor of low and mid range torque and power especially using straight unrestricted pipes, but what happens if you use true duals and slip on mufflers with baffles. I have read where one should use either torque cones or baffled mufflers to create back pressure. Just about all slip-ons have baffles so is it logical to assume that the baffles help with the reversion wave and if you are using true duals would they slow the wave down enough to not hinder the torque. If that is not that case would installing torque cones with true duals and baffles work like stock set up for torque?

randy

Apr 28, 2018 | 09:32 AM

EdwardK

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Joined: Nov 2007

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From: Houston, Texas

I'm no export but I have a bike with true duals and another with 2 into 1 into 2. A previous bike had a 2 into 1. If you are buying a complete true dual system, the manufacturers engineers have designed them to function properly. I wouldn't change or add anything to their system to modify it.

The key is having it properly tuned. A 2 into 1 or 2 into 1 into 2 is better for torque but the loss in true duals may seem like a lot on the dyno chart but you probably wont feel it or it if you do, it will be a minor difference. Add a good cam with it and you really wont notice.

My suggestion. Find a reputable indy that has a dyno. Chat with him about what you want ( sound, torque, HP, performance, fuel mileage, etc ), and he can makes some suggestions and then tune it to meet your needs with the pipes you decide on.

Of the four different exhaust systems I've had, the Rinehart True Duals have been my favorite for sound. 127,000 miles and they still sound sweet and have actually mellowed out over the miles.

Good luck on your decision. Choosing the right exhaust to get the performance, sound and looks you want is a daunting task

Apr 28, 2018 | 09:50 AM

cajun1957a

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My 2003 RKC runs very strong. I have S&S 510 cams, V&H true duals, 4" Street cannons, High flow breather and a power commander 5 with auto tune. I'm not a torque nut or power chaser even though I have all these toys, I look to having the motor run "reliably" as I can. I currently am getting more than 50 mpg (Canadian gallon), and am really happy with its performance. A discussion with a buddy came up about torque cones he was installing on his bagger and I was under the assumption they really only work with straight pipes do the lack of sufficient back pressure. I didn't know if they would benefit a bike with baffled exhaust even if they were true duals.

thanks

randy

Apr 28, 2018 | 12:25 PM

0ldhippie

Ultimate HDF Member

Joined: Mar 2012

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From: Santa Cruz

Torque cones are and have always been a band aid for a poor exhaust. They have nothing to do with performance. Baffles are for noise reduction, again nothing to do with performance. Can’t beat an exhaust properly designed for other engine components...

Apr 28, 2018 | 12:56 PM

OldPhat

Elite HDF Member

Joined: Dec 2007

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From: Sparks Nevada

Torque Cones are an old fix for improper exhaust, or straight pipes, getting a correct
exhaust system for the Bike will eliminate problems, sound better, and run better too.
There are different sizes of baffles you can use in mufflers to set the back pressure for
what your Bike needs. My Son had a 04 Road King, with Rinehart True Duals, it was one
of the best sounding Bikes out there. IMO.

Good luck on your search for more bottom end torque, but I'm not sure Torque Cones
are your answer.

John

Apr 28, 2018 | 01:43 PM

grbrown

Club Member

Joined: Jun 2007

Posts: 45,429

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From: Bedford UK

With pipes and proper mufflers you don't need any sort of additional baffles. As suggested above, they are a backyard fix that have no place in a decent system, which it seems you already have.

Apr 28, 2018 | 02:33 PM

Bafflingbs

Stellar HDF Member

Joined: Jul 2015

Posts: 2,659

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From: Maryland

Each detonation creates an exhaust pulse. The faster the pulse is, the more of a void is left behind. This void creates a vacuum. The vacuum assists with drawing in fresh air and fuel, on the intake cycle. This is called scavenging. In a 2-1, one pipe is able to help speed the velocity of the others pulse, and visa versa. True duals rely solely on their own exhaust pulse. Remember, your engine is basically an air pump. More air in, more air out. The 2-1, is hands down, the best exhaust design. Then 2-1-2, and lastly, true duals. Baffle size, also plays a major roll. Contrary to belief, a wider opening is not always best. Also remember, you’re shooting for velocity. Too wide, and you create turbulence, which is bad. Think of it like this; when you blow out a candle, do you you open your mouth as wide as you can? Or do you pucker up and blow?

You are NOT seeking back pressure. You are seeking VELOCITY for the escaping exhaust gasses. While the torque cone does help with velocity for a short run within the exhaust system, the exhaust pulse slows down again once it reaches a wider part of the pipe. Thus, defeating the exhaust’s pulse velocity and the scavaging effects of the vacuum left behind the pulse.