View Full Version : maximum noise for 2003 carbureted flsts

08-10-2009, 06:14 AM

I have a 2003 carbureted fltsts with Supertrapp muffler 3” Internal Disc Series HD FLSTS/C Sprngr Fishtail 97-07( 628-78056).
dynojet thunderslide kit ( with BJ195)
twintec ignition TC 88 ( initial timing 5 advance slope 7)
screamin eagle airbox

how many discs do I need for maximum noise.
how many discs do I need for maximum performance.
should there be the same number of discs in each muffler?

I would like to install open end cap.
(currently I put 18 disc with closed end cap but but I dont have a lot of noise)

thank you very much.
best regards.

08-10-2009, 10:45 AM
Maximum noise would be achieved by using no discs at all.

With the stock cross over head pipe, use 3 more on the right vs. the left.

08-10-2009, 02:10 PM
What are the risks for the engine if I use the supertrapp muffler without discs ?
Should I install a jetting more little (BJ165 or BJ170...) ? Or Can I let BJ195 jetting ? Or should I install a bigger jetting (BJ200 or more) ?

Thank you very much.

See you soon.


08-10-2009, 02:53 PM
No discs=very little to no back pressure and the bike will loose bottom end power. You are already at 18 discs, so it's pretty close.

If your jetting is good with the current set-up of 18, then it should run ok with trying it without any. You will have to try it and see however, every bike is different and we can not test every possible senario.

Try it and see if it's enough for you.

08-11-2009, 07:34 AM
in summary:

No disc = maximum noise.
no damage to the engine except to loose bottom end power.
no need to change main jet (I keep the BJ 195 main jet)

see you soon.


08-11-2009, 07:55 AM
You got it.

08-13-2009, 08:09 AM
I have another question:
loss bottom end power = increased consumption of fuel?
Thank you for your professionalism.

08-13-2009, 10:06 AM
Hmmm, shouldn't be, but I guess if with a lack of bottom end, you are twisting the throttle more to try and make up for it?

02-09-2011, 12:21 PM
What happens if I remove the rockwool from my muffler and what is the risk for the engine of riding without baffles.
Thank you.

02-10-2011, 07:10 AM
Running without packing inhibits performance and prevents a nice clean exhaust flow through the core.
No baffles puts you at risk of running lean.