Exhaust Torque Cones ... data

[DarrellV]

Anyone have any real data on Exhaust Torque Cones? I'm talking about the ones that ride inside your pipes, next to your heads. I have ran motors, with them, and without them, but maybe not with the same Carb. and same set-up motor wise. I understand the theory behind them, but I'm wondering if anyone "knows" or has proven out the theory that they work and believe in them. 

[Max Headflow]

Here you go. 1 run with 1 without..

116 FXDX
10.8 to 1 cr
custom CnC heads
Crane 314 cam
Super G (bored 1.85 with Tjet) 1.62 port manifold
Pipes were AR100 pipes which have torque cones built into the flange. The flanges were subsequently bored to 1.610 from about 1.475..
No jetting or timing changes and done 3 days apart

Runs done in 5th..



Max

[DarrellV]

Max, thanks for your help and time. I'm having trouble reading your numbers? Which line is which? I'm guessing your a beliver in the Torque Cones It looks like a Hot Low Rider for sure. Bet that lite of a bike is a blast to ride too.

[hrdtail78]

Graph shows me no difference between having them or not.

[Max Headflow]

Try hitting ctrl+ while in the browser to zoom in..

The red with was with the cones, blue without..

Red did the slightest bit better down low, blue did better up top.. This is no way the definitive absolute answer..Others might get different results.. with different heads, cams, displacements, pipes, carbs, throttle bodies, day of the week, leap year, coriolis forces etc,,

Max

[hrdtail78]

Been awhile......
The control C doesn't work on this, but has in others.  Thanks.

Would you consider these equal to the cones you drop in?  I ask because I have seen to many drag piped bikes go straight rich between 2800-4000 and tq cones do nothing for that.  Put some small, 3in. baffles in and the A/F straightens.  I have been able to fix some 5,000-6plus richning conditions w/ tq cones.  This is all with carbed bikes.

[Ajayrk]

Been awhile......
The control C doesn't work on this, but has in others.  Thanks.

You can always click "view" in the menu and select "zoom."

[FLTRI]

My experience is that if the cams have a lot of overlap

and

the exhaust is virtually straight and open, the cones will help a bit on the bottom end to lessen the effect of reversion, which is why they are called anti-reversion cones.
Hope this helps,
Bob

[Ken R]

If you were to dyno the same bike twice, 3 days apart like above . . . but with no changes at all, would the resulting dyno graph be exactly the same or would there be difference?
 
 

[strokerjlk]

If you were to dyno the same bike twice, 3 days apart like above . . . but with no changes at all, would the resulting dyno graph be exactly the same or would there be difference?

they will be diff. while not much they will be diff.
look at the conditions on the sheet.
because of the conditions the software used a diff. correction .99 vs 1.00
barometric pressure ,humidity, ambient temp will make a diff. the correction process does a good job but isn't perfect therefore you will see a diff.
not discounting this test at all as it as close as it gets sometimes. even on the same day in the time it would take to swap the pipes the conditions can change enough to see the same results as Max posted.

[strokerjlk]

JMO....if you have to run anti reversion cones then you either have the wrong pipe or cam for the motor.
changing the characterises of the pipe (high and low pressure waves)  will result in a compromise somewhere. while very slight in this case.
I doubt there was a reversion problem on this combo to begin with. again just my opinion because like any other pipe or cam we all like diff results.

[DarrellV]

I agree with Stroker, But my take on the matter is if your looking only at Dyno. paper work, then you focus and get the best numbers you can get how ever you can get them. If your working/ riding a bike everyday for fun. Then you have to factor in things you like and parts you already have and use the Dyno. as a tool to make it run as good as you can by dialing it in.
On a Dyno. everyone knows a 2 to 1 pipe works really well. But on A Bagger, Ture Duels just looks "Right" and sounds "Killer" to me.  With that being said question comes to my mind, would Torque Cones help TD's perform "better" ?
Better being the key word there, LOL.

[FLTRI]

...... would Torque Cones help TD's perform "better" ?
Better being the key word there, LOL.

If the performance issue with tru-duals was caused by reversion, then an anti-reversion device would probably help.
However the issue is with 2into1 performance vs 2into2 performance as related to the baggers. I believe there isn't a reversion issue with the full length bagger exhausts.
A well designed 2into1 exhaust will always out performance any 2into2.
Hoping this helps,
Bob