I see that some people are running screaming eagle exhaust on their thumpers. What years am I looking for? What size is pipe? I looked at several websites and there is so many different types for different models. Also, can you purchase them separately or only as a pair?


Thanks,

   Ghstrdr110

Looking for a dyna model with rail type mounts. I got mine brand new on ebay for $25. Its pretty freakin loud. At idle its tame but once you get past 1/4 throttle or so it get progressively louder. I work nights and its loud enough that Ive been cautious and keep the revs low as I come home. But I also tend to leave again (say..between 1-5am) so Im sure Ive pissed off some light sleepers in the neighborhood. If you have a normal schedule I think you'll be fine.

Jim, i gotta tell you, that is about as impressive a piece of shadetree blacksmith work as ive ever seen... a "county mountie" valve.... street racers used to do about the same, only the butterfly would choose either a path to mufflers, or an open leg of a y-pipe... whisper quiet for the challenge, open and uncivilized for the run.... might stll be able to find them on jc whitney...

marshall13 wrote on 05/10/09 at 10:40:36:


Thanks.  I use it around town in stoplight traffic where I often get a cop behind me waiting on a red light.  My bike isn't obnoxiously loud and pretty much blends in with most harleys around here. But the sound can ricocchet off of the downtown buildings and make it sound louder than it really is.  

I made a different baffle that is only 5" long that sits just in front of the butterfly.  If open drag pipe on a volume scale is a 10 and stock muffler is a 1, my pipe with the butterfly open is probably a 7-8 and with the butterfly closed maybe a 3.  

I mounted the cable here:


And this is the cable pulled and the butterfly in the closed position:

Wow!  I saw an average price of $850-$900.  Makes me like my $20 setup even more.

Actually, the one pictured is version 1.  It worked pretty good.  Version 2, which I'm running now, is pretty much 90% of what Version 1 was but with some improvements.  However, I don't think I took any pics.  It uses the same mounting plate.  The differences are that 1) the arm is half the length, 2) the stem inside the pipe is flattened on one side to center the washer, 3) the profile (when opened) was reduced to minimize airway obstruction and 4) the washer is perforated with a dozen 1/16" holes.  But it's the same concept as the one pictured.  Perforating the washer decreased the pressure which decreased the volume a little more while still diffusing sound.  I'll have to find my camera just to make sure I didn't take pics of Version 2 but don't think I did. As for heat, I installed the heat shield behind that section of pipe when I first installed the exhaust to protect the heat sensitive stuff in that area.  No evidence of any heat problems thus far in that regard. I was initially concerned that heat would cause metal expansion and binding of the butterfly action but no problems with it so far whether opened or closed.  It would take about $5 and an afternoon to make another one if ever needed.