Wasn't sure where to put this and didn't think it warranted its own thread so here ot it is...
I installed a set of W158 Thunder Torque Inserts in my Samson Street Sweeper clones today.
This is a stock internals 1999 Twin Cam with a Mikuni HSR42 and custom air cleaner similar to a DK 636V. Fully warmed up, mixture corrected, and idling at 1000 RPM.
The inserts are installed about 1" inside the turnout, centered inside the pipe, and oriented perpendicular to the long axis of the pipe with the tip of the "cone" pointing upstream. Typical install, I'd say.
I took these measurements with a calibrated mic from about 10' away on the exhaust side, directly across from the exhaust tips. The bike was sitting on its side stand in an open area to minimize echo and reverberation.
As you can see, the overall SPL (loudness) was reduced by about 6 dB. I can't remember what weighting curve I had set, but it was probably flat since I tend to use this mic and app for impromptu audio system tuning.
My impression of the sound is that it lost some higher pitched "bark" at roll-on and there was a reduction in low pitch reversion "echo" (kind of a flabby chuffing sound). To my ear, with these pipes, the tone isn't significantly lower but it is a bit cleaner or more refined sounding.
I can't really comment on how it affected power/torque as it's been over 2 years since I last rode the bike and I have changed so much on the bike since then.
Please keep in mind this is one sample on my specific setup and may not reflect your experience.
Edit...this was intended for the Dyna forum (stupid search function!), but maybe y'all will find it useful too.
Wasn't sure where to put this and didn't think it warranted its own thread so here ot it is...
I installed a set of W158 Thunder Torque Inserts in my Samson Street Sweeper clones today.
This is a stock internals 1999 Twin Cam with a Mikuni HSR42 and custom air cleaner similar to a DK 636V. Fully warmed up, mixture corrected, and idling at 1000 RPM.
The inserts are installed about 1" inside the turnout, centered inside the pipe, and oriented perpendicular to the long axis of the pipe with the tip of the "cone" pointing upstream. Typical install, I'd say.
I took these measurements with a calibrated mic from about 10' away on the exhaust side, directly across from the exhaust tips. The bike was sitting on its side stand in an open area to minimize echo and reverberation.
As you can see, the overall SPL (loudness) was reduced by about 6 dB. I can't remember what weighting curve I had set, but it was probably flat since I tend to use this mic and app for impromptu audio system tuning.
My impression of the sound is that it lost some higher pitched "bark" at roll-on and there was a reduction in low pitch reversion "echo" (kind of a flabby chuffing sound). To my ear, with these pipes, the tone isn't significantly lower but it is a bit cleaner or more refined sounding.
I can't really comment on how it affected power/torque as it's been over 2 years since I last rode the bike and I have changed so much on the bike since then.
Please keep in mind this is one sample on my specific setup and may not reflect your experience.
Edit...this was intended for the Dyna forum (stupid search function!), but maybe y'all will find it useful too.
Very interesting & informative charts! Do you mind if we reprint them?
Very interesting & informative charts! Do you mind if we reprint them?
Feel free!
The tools to do it yourself are very inexpensive. I'm using an Android app called Audiotool and a small mic from Dayton Audio, model iMM-6. I have a more accurate and powerful setup that's PC-based but I use this combo a lot for quick measurements on the go.
The overlay was done on a PC using a free graphics program called Gimp. It's very similar to Photoshop but doesn't cost $500.
The tools to do it yourself are very inexpensive. I'm using an Android app called Audiotool and a small mic from Dayton Audio, model iMM-6. I have a more accurate and powerful setup that's PC-based but I use this combo a lot for quick measurements on the go.
The overlay was done on a PC using a free graphics program called Gimp. It's very similar to Photoshop but doesn't cost $500.
Yes, the Q style Thunder Torques are a nice version of a lollipop, but the W Style TTI's are substantially different, with a patent pending.
I came back to this thread today because I just received the following email from N Ireland and wanted to share it here-
Guys, received my torque inserts last thursday and fitted on friday evening and wow what can i say they do exactly as they say, i now can ride much longer due to the deeper note of my exhaust,it sounds exactly as i always wanted it to, and i immediately felt the power increase right through the range, i cant tell you how pleased i am, awesome! Thank you for all your help, im now running around telling everyone about these so hopefully you will see more orders from N Ireland.
Thanks again
Dave
are these meant to be used with or without the baffles? I just put on V&H twin slash with standard baffles and would like to try them?
are these meant to be used with or without the baffles? I just put on V&H twin slash with standard baffles and would like to try them?
You can use them with or without baffles, either way they increase your low and mid range power and deepen the tone a bit. There is more info at this LINK.
10-08-2018, 07:16 PM
