Thanks man, The V&H slip ons with their stock baffles are pretty much straight thru and the QB's at 2-3 db's are not much quieter. The Smartpartz sound like just what i'm looking for, quieter idle, cruise and still have that crack the throttle sound your talking about when I want it..Between those and the 2 different baffle sets i have, I should be able to get the sound I'm looking for. Otta e-mail them and ask for a kick-back for making a sale for them.. Worse that can happen is I have another MC paper weight sitting in my garage..thanks again

 

Big City Thunders were mentioned so I thought I would chime in. We definitely don't have the same goals though. *LOL* I put Bub 7's on a while ago. Just a tad quieter than Rhineharts. 2 decibels? Sound was incredible. Real low deep rumble. I decided it wasn't loud enough and did BCT's. Basically BCT's do not make pipes any quieter BUT they eliminate ALL decel and give you the power straight pipes loose. BCT is NOT what you want to make pipes quieter, just the opposite.

 

I really don't mind them loud, cept it's gotta be the deep rumble and not a tinny sound..I love hearing the sound bouncing off cayon roads..Stock would never cut it, but I just don't needed the hassel of some cop who might just have a bug up his @$$ that day. I'm old and ornery and just might tell him what he can go do to himself.. another thing that pee's me off, though it's their problem not mine, is folks that roll their windows up when your next to them at a light or pull up on the highway to be ahead of you when their on your right cause it bothers their sensitive little ears...It's not that freakin' loud @$$bites..OK, I feel better now..

 

BCT has two versions. The regular ones that everyone talks about and ones called QQ's. The QQ's are the same exact baffle but they have a cone attached to them. The cone takes the decibels down just a little bit and gives the pipes a deeper sound. Cone could of course be removed if you want (welded). I have the QQ's. Never gotten hassled about noise.

The sound is not quite as deep as my Bub's were with their original baffles. Honestly, preferred the sound of Bub's baffles (deeper) but I wanted them louder. There is a middle ground though if ya want to take the time to find it: Once you have BCT's or QQ's in place you have completely handled all back pressure concerns to avoid decel and to keep HP/torque up. Since they mount an inch BEFORE the slip-ons start you could still have factory baffle. As you slowly cut the baffle down to nothing the bike gets louder and looses bass. Stop cutting down baffles when you are happy.

 

From following all of this, it sounds like I need to consider the torque thing in my plans.

I have been planning on going with the Vance & Hines Big Shots Staggered Black with their quiet baffles installed (which only quiets it a little), and follow that up with the Smartpartz baffles to quiet and deepen it some more.

But what exactly is going on with the "decel" and torque that I am hearing about? It sounds like a problem.

 

Decel is the popping noise you hear when you let off on the throttle and air gets sucked back into hollow pipes. Decel is annoying to most people (bikers included) and bad for the engine.

The engine needs a certain amount of back pressure to produce the desired (most) amount of horsepower and torque.

With NO baffle you get decel, loss of HP, and loss of torque.

If you use more than one baffle it is the first baffle that effects performance.

BCT baffles take care of decel. HP, and torque, while retaining 90% of the sound/loudness of straight pipes.

 

I would think twice b4 using two sets of baffles. If V&H makes Quiet baffles then they must also make regular baffles that are not so quiet. V&H regular baffles are going to be quiet enough to keep the police from hassling you, so QUIET ones will be QUIET enough for most peoples standards.

Where do Smartpartz baffles even mount? Getting two baffles into one pipe is not an easy task. BCT's mount in header. My Bub baffles where the length of my slip-on and mounted from the back. I don't think it is very easy to get 2 baffles in one pipe.

 

Thanks for the info, Dew Me. Are the curved pipes, like the V&H Big Radius. the same as straight pipes when it comes to required back pressure? Or does straight pipes just refer to pipes without the stock muffler/etc?

I assume that the standard V&H quiet baffles are designed to give the Big Shots the required back pressure. But according to V&H they are only a little quieter than the stock pipes.

According to Smartpartz, their baffles are designed to go in with the existing baffles and lowers the sound 6-12 decibels, increased back pressure, etc.

My ears have taken a beating over the years, so with that along with noise ordinances, I need to keep the sound down.

 

The Smartpartz baffles are small. Exept for the collar they fit/slide into the existing baffle.

 

Like he says. Look like this, if i pasted the right page (for my V&H SS slip ons anyway)
http://www.smartpartz.com/SPZVHSS.html .

The use the same baffle/pipe screw to mount into the end of the exsisting baffle so they really become one baffle..There designed to work with the stock baffle which is pretty much straight thru pipe except for some louvere type cuts on the perimeter of the baffle pipe. The quiet baffle (which i think was shorter also. Can't remeber) has a small stop plug at the front forcing the exhast gas to go thru smaller holes and is wraped in a fiberglass mat to absorbe more of the sound. I doubled wraped mine and it ain't bad (loud) really)..SP says they will work on the quit baffle also but recommend the stock baffle. I'm gonna try stock first and see how that sounds..On SS slip ons changing baffles is fairly eazy..