Right now I've got stock header pipes and Rhinehart slip ons on my 12RK.
Question #1, is it a waste of time to even think of putting anything other than the RH header pipes in to get my true duals??

#2 What's the cause of loss of low end torque with true duals (or so I've read)?

#3 Anyone gone to duals that wish they would have stayed with stock headers?

 

The loss of torque and HP is due to the lack of back pressure in a true dual setup. I am set to go with the new slimline duals by RH. According to the dyno guy I have talked to, they dyno the same as the Vance and Hines power duals.

They might not sounds quite as good as the true duals however.

 

i like the classic look of the true duals and the rumble of the exhaust.

i had V&H power duals, i may have lost some torque and hp.

 

Truth be told, you can gain HP with true duals, but may lack some TQ.

Your *** dyno will never feel those small gains or losses.

Go with what you like.

How many 2/1 setups do you see on the dragstrip?

 

Truth be told, you can gain HP with true duals, but may lack some TQ.

Your *** dyno will never feel those small gains or losses.

Go with what you like.

How many 2/1 setups do you see on the dragstrip?

 

2. It's more the case that bringing the pipes together provides a bonus! If you look at any recent Buell they have equal length pipes, which may look ugly, but they enable the designer to increase CR and use much wilder cams, giving more power and torque, while still meeting the same EPA regulations as all Harleys.

With a near stock Harley, power for TDs will be similar to any of the siamesed systems, but torque will be improved. I ran TDs on the bike in my sig pic for a while, before swapping to the Supermeg you see and had both set up on the dyno by the same shop.

Headline numbers were similar, with the 2-into-1 giving a little more peak torque, however the low/mid range torque was up to 15% higher with the Supermeg. In addition the engine is far smoother and just a lot nicer to ride. So there is more to the difference than meets the eye!

3. I never used stock headers with this S&S 107" engine, but no way will I go back to TDs.

4. I would expect your stock pipes, with suitable mufflers, to give better results than any TDs.

 

I just put true duals on last week.
My impressions:
Do not notice any difference in HP or Torque. As Safetyman said, your *** dyno won't notice. I ride solo
Throttle response is better.
Sound is much better, not louder.
Way less heat on my leg.
JMHO

 

I tried V&H true duals several years ago and could not get them off fast enough. Maybe it was the mufflers I was running but it just felt like my head was being jack hammered.

Rick

 

Wow...never heard that one!

 

Thanks for all the comments. I probably don't need to know much in terms of going too radical with my exhaust, but need to admit I am really confused.
I was thinking that "true" in true duals simply meant that the pipes didn't crossover, and were more like straight pipes.

I had assumed the RH slimline duals were "true duals". Anybody have a good source to read up on what I need to know before plunking down some pretty good cash? Appreciate it!