Cones or no cones on true duals? What do they do? And if they do, how much do they do?

 

Cones will add a little backpressure that you lose when going to a True Dual system. The loss of backpressure usually means you will lose a little Torque down low.

Are they worth it? That I don't know. To find out you would have to install the True Duals and then dyno tune. Then install the cones and do a dyno run to see the difference.

Not sure if anyone on the board has them or don't remember anyone posting about them.

Got a link to them??

 

I've got cones in both my bikes, I noticed a difference. No back fires. The carbed bike has street sweepers and runs great.

 

websterdan are you running true duals with the cones? If so, where you get them & how much?

 

Actually, there is a mix up with the terminology, but you give the right end result. In reality, you don't need the back pressure. What you need is the resonant wave that goes from the back of the pipe back to the head. In Drag Pipes, you can more reliably and efficiently "tune" these waves to work for you by using a stepped pipe. (where the pipe begins at say 1 3/4" and changes one or more times "stepping" up to 2 1/2"). If you don't have a stepped drag pipe (or if you do and the manufacturer still recommends them, which is doubtful) and just have a straight drag pipe (same size pipe all of the way through) the you could slide in a set of torque cones to somewhat do the same thing.

I would be here all day to try and explain the science behind this...

As far as true duals, that could be anything. You can have a 'true dual' from the factory. I am assuming that you mean without the crossover. Having a crossover actually helps you gain low end torque, by the same scientific process as having torque cones. They are tuned at the manufacturer level by there placement away from the heads. Compare a '90's EVO softail with an 06. The 90's softail had the crossovers 1/2 a foot from the heads. The 06 has them where the mufflers bolt on. Tuned differently for different engine characteristics.

Sorry, my first post. I just had to chime in, as I am kinda tore up for the misinformation that has been going around. (Not saying it is from here, it is just stuff that has been flowing around for years in the motorcycle crowd.)

So, as my first post, I would like to note that I am a diesel mechanic and have been for 15 years. I work full time for the military, and I ride an 06 FXST, while the '80 Kawasaki rusts in the back yard.

 

Ok, dumb question. If you run truals with out the cross over pipe, what can you do to increase torque? Cones? If so what do these cones look like on the bike?

 

Here's a link to power cones: http://www.jpcycles.com/productgroup...5-33E6DED0F6FB

Since they go inside the header pipe, there is no change in the looks of the bike.

 

Here is a link kinda describing (better) what I tried to do above... (I am no scientist)

http://www.jpcycles.com/Tech/Articles/needtorejet.aspx

 

Just as an FYI, after I put my Samson true duals on, I deliberately ran them for several hundred miles to see what changes there was between them and the stock pipes. The only difference I found was a major loss of low end torque and my acceleration was a lot slower. I put in the stainless cones and noticed that the torque and acceleration came right back to where it was before I changed out the pipes.