torque cones

[Jared]

I have yet to install mine. I'll be doing my swing arm maintenance and want to wait until then to remove my exhaust.

From what I have read, a few prople have used just a bit of foil, wrapped around the cone, to hold them in centered. Not too sure if it would matter too much if they were slightly off center.

They look like something you could easily make and design to better fit our pipes. Maybe that would be something else you could offer from your site.

[VulcanE]

Originally Posted by James "Bubba" Andreu

You guys using these with stock pipes? I see in the sig pics it looks like VulcanE has Cobras but lonewolf looks like stock debaffled.

Would not think the stock pipes need these, normally they are only a benefit with open exhaust.

James, my pipes are Vance& Hines, and your right, these are not needed with the stock exhaust. The are designed for two reasons, 1) to get back low end torque you loose by really opening up the exhaust and thus you loose your back pressure, and 2) they are also called "anti-reversion" cones, this affects Sonic pulse, thermal pulse, and exhaust gas velocity.
* Sonic pulse. Think of this as a shock wave. This pulse travels through the exhaust and at the end of the pipe actually turns around and heads back toward the exhaust valve. The wave will also pull exhaust gas back along its path and if it reaches the open exhaust valve the gases will dilute the air/fuel mixture in the combustion chamber. Under the right (or wrong) conditions this wave will even push some of the air/fuel mixture back through the intake valve into the intake, a common occurrence with short drag pipes.
* Thermal pulse. Similar to sonic pulse, this is a wave created by the hot gas exiting the exhaust valve. The thermal pulse also reverses direction at the end of the pipe but unfortunately travels at a different rate, thus reaching the combustion chamber at a different time.
* Exhaust gas velocity. This is the rate at which gas travels through the exhaust system. The optimal velocity is 300 feet per minute. For the most part all stock engines require a 1-3/4" diameter pipe to maintain 300 fpm. Bigger is not always better and a larger pipe will actually slow this velocity thus restricting flow. One trick is to install anti-reversion or torque cones. When installed inside the head pipes these cones act to repel the pulse waves as they return to the engine and alter velocity as the gas passes through the narrower passage.

Disclaimer, I copied and pasted this ;)

[chuckster131]

Ok, Took off the pipes and set the cones in with a bit of silicon to hold them center, will reinstall tomorrow. That will hold those cones centered and make the job go easier.

[mikeyger]

I have ultimate baffles in my vance-hines pipes.I think vulcan e has the same set up!

[billmac]

I have found this back pressure info very interesting and just ordered some cones off the ebay site listed in this thread. My 06 1600 has TFI, Open Intake, and V&H.

I recently put on the V&H and the pipes seem to have stolen a considerable amount of low end torque. I don't need a dyno to tell me the bike does not perform as well as it did with the drilled original exhaust. The Nomad now feels sluggish. Apparently the TFI, open intake, and the drilled original exhaust was a great combo. I am hoping the cones will bring my power back and let me keep the sound.

Thanks for the info and appreciate any comments/recommendations on my set up.

[mikeyger]

billmac, The cones don't change the sound and as vulcan e says will give you back the "getty up an go"you lost!

[chuckster131]

Had a chance to get out today for about a 40 mile ride and I think the cones do add abit more low end...... 20.00 bucks well spent in my book..

[Jared]

Glad to hear they worked out well for you, Joe!

[dregier]

I just ordered mine today. I will see if they help with my V&H Baggers.

[oldbikers]

Do these fit up to the heads? The reason I asked as V & H baggers all ready have a problem cracking at the head pipe.

[chuckster131]

Originally Posted by oldbikers

Do these fit up to the heads? The reason I asked as V & H baggers all ready have a problem cracking at the head pipe.

These fit right in the pipe, I used some silicon to keep them centered up. Worked great for that..... Then just put the pipes back on with new gaskets.

The problem area of the back pipe cracking is down from the top about 6-8" from the engine.

[Cajunrider]

Mine came in during the week. Went to the local HD dealer for gaskets and as my luck would have it, they were out of stock. Killed that project for today. Ordered a couple of sets off of Ebay for $19.00 with free shipping.

[dregier]

I put mine in this weekend and then took a 250 mile ride. I honestly can't tell much of a difference. Maybe a little less decelerating popping noises.

[oldbikers]

torque cones were designed for open pipes especially for the short drag pipes on a Harley.

[billmac]

Originally Posted by dregier

I put mine in this weekend and then took a 250 mile ride. I honestly can't tell much of a difference. Maybe a little less decelerating popping noises.

Aw heck, hate to hear that. That also means Old Biker is right again. Nuts.

Guess I will put mine in. I bought em and it should not hurt anything.