Ok, here are a few pictures of the baffle from my 2009 V&H FLHT pro pipe. Are the popular(effective) baffle mods as simple as drilling a 1/2" hole into the center plate? Unwrapping the the black wrap from the 4 rows of holes and just covering 2 of the rows? Do both ? Not really interested in making/maching a Supertrapp disc end cap.Thanks for any input pro pipe owners or from others in the know....

** Found this info on two year old thread on another forum. Could this be it?
The standard baffle needs to be drilled out in the back to a hole size between .25 cents to 1 inch.
That will give you some back pressure relief for a slightly modified motor.
Once you do that, then use hose clamps over the perforated section to dial in the back pressure you require to give you a good torque curve.

 

Not exactly sure of the mod you are talking about. I have a ProPipe on my 103 FLHTP and I removed the wire packing and glass packing. No loss in performance but a lot louder. Could not hear my radio. I then bought more 1/4" thick packing on ebay and wrapped both sections that fiberglass muffler packing. Quieter than stock now.

 

hey troop, this is jim. when we dialed in my motor on the dyno we ended up drilling a half inch hole in the center of the round plate that causes the exhaust to go out the sides of the baffle. it did make my bike a tad louder, but certainly not obnoxious at all. just a deep thumpin' sound that barks with authority when you yank the chain. hey man, i finally figured out how to use the "search" feature here in the forum.

 

Morn'n,
I think I'll start out with a 1/4" or 3/8" hole, leave the fiberglass wrap intact, remove the wire packing and wrap two of the four rows of baffle holes. That hole might just be enough to relieve back pressure to compensate for my cams and slightly higher compression. I do have a message in to V&H but not expecting much info regarding a baffle mod...

 

What was the result?

 

I talked to Jamie at FM and he said I should pop off the end cap to help with a TQ dip associated with this pipe. Not wanting it too loud, I kept the stock baffle wrap intact and opted to drill the cap out 1" and have it tuned that way. The end cap is approx. 1-3/4". The result was very good as the torque line was very straight with no lower rpm dip. That said, my first cruise at 70-75mph down the interstate left the volume a bit too loud for my taste. I got home, removed the baffle and used (2) fender washers, nut/bolt to seal the hole and try it stock (exhaust installed over winter and only heard it at idle). Surprisingly, it wasn't much quieter this way although the decel tone sounded better. Knowing I spent good $$ to have the bike tuned with the 1" hole, I came up with this idea. I drilled (5) equal spaced 3/16" holes around the washer, basically creating a 15/16" opening but not with one hole. The bike sounds good, runs good and but has a nicer tone on decel than the 1" hole. I'm happy

 

Five 3/8 holes is .552" area of an opening and one 1" hole is .785" area. I did read 3/4" was optimal for torque and hp on the original ProPipe baffle which did not have the outside perimeter area for muffler packing which V&H used stainless wire. I ended up with a 1" opening in the center. Noticed no louder than stock and seems to pull better low down at 2500 rpms.

 

How did you originally come up with 1" hole? Did you have a before tune? Did you have a torque dip with stock baffle? Was there a difference in power with the 1" hole? Thanks for the input.

 

Good advice from Jamie. The plug just kills the power. Here are 2 that were tuned and then cut the plug off and retuned. I would also expect a little better fuel economy as once the plug was removed the bike was rich below 3000 rpm. Now I don't even check. The plug is gone.

 

So with a 1" hole in the center of the baffle its no louder than the stock baffle?