Triumphrat

idahotb · 03-28-2005, 02:23 PM

I know that 90% of the exhaust posts are on how to increase the sound of the pipes, but I want to do the opposite. I bought a used '96 Sprint 900 last year, that came with D&D slip ons. Now, I added the TORs to my TBS and really love the way they sound; but the D&Ds are LOUD! I am thinking of trying to make some kind of insert to temper them just a bit, but I have no real clue about designing exhaust systems.
I pulled the cans off the bike but haven't cracked them open yet. Looking in, there is a perforated sleeve the same diameter as the exhaust pipe that runs the length of the can. I am assuming that this just acts as an expansion chamber that reduces pressure and slows the exhaust velocity. Putting some sort of packing outside this would seem to be counter productive. I am contemplating loose packing the sleeve with some sort of material (loose fiberglass or course steel wool come to mind).
So my questions are:
1) If I am careful not to create too much back pressure can I screw anything up? (If anyone can, I can)

2) Has anyone else done anything similar? I am nuts to do this?

3) I am nuts to ever try this?

4) Any other suggestions or comments?

Thanks folks. You are a great resource.

I-da-ho

SWare · 03-28-2005, 03:58 PM

D&D pipes are notoriously loud.
Have you checked with them for a packing kit or some such?
Some of the sport bike silencers of other brands have them for when the packing starts to deteriorate. Maybe some of the material from one of those would work.

No hands on here just read about it or seen ads etc.

Stan

:brk: :razz:

tango · 03-28-2005, 06:15 PM

A removeable baffle would be the thing.

Many manufacturers supply them with their exhausts for on and off road use.
They make a huge difference to the loudness.

Copper · 03-28-2005, 09:58 PM

Some of the guys over on the Twin forum have put baffles in their pipes to quiet them down a little....Heres a link to a post that has pretty good info, I'm sure the author could help you out.....

Baffle post

Copper · 03-28-2005, 09:58 PM

Some of the guys over on the Twin forum have put baffles in their pipes to quiet them down a little....Heres a link to a post that has pretty good info, I'm sure the author could help you out.....

Baffle post

CarlS · 03-31-2005, 07:42 PM

Idahotb, I started the thread to which Copper refered. I installed JC Whitney baffles in my adapters to tone down my BellaCorse Teardrops. Baffles can be purchased in different diamemter sizes. I do not know what diameter baffles you would need for D&Ds on your Sprint. Since you have pulled the mufflers, measure the diameter of your header pipes. You might be able to install baffles there. That is essentially what I did with my Bonnie. Read through the thread including 'Dweeb's comments. Feel free to ask me any questions.

idahotb · 03-31-2005, 09:02 PM

Carl- Did the baffles in the adapter make the bike run a little rich? Did you have to mess with the carbs?

Thanks to everyone else who responsed. I will take a look and let you know how it turns out..

Now pray for sunshine!

I-da-ho

CarlS · 04-01-2005, 06:20 PM

I-da-ho,

Anytime that you change the exhaust flow, you will affect the mixture. Keep in mind that I have a Bonneville. When I installed the Teardrops, I rejetted to 130 mains. I did not change the pilots. I was a little lean at lower rpms and at midrange. Installing the baffles made it run a tad on the rich side; but not overly so. I did not rejet because I am going to install Thruxton needles and I will definitely have to rejet. I'll start with 115 mains with the Thrux needles. My guess is that without the Thrux needles and with baffles installed, I should be running 42 pilots and 128 mains.

Here's hoping you have good weather!!