I had a hole in the end of mine also. It was put there to allow the sniffer on the dyno to be inserted into each head pipe rather than just the collector. Over a couple of years I experimented with blocking holes, adding fiberglass packing, etc. To be honest, I really couldn't feel a difference in my butt dyno. That was good, as I was really trying to get the pipes a little bit quieter. A couple of weeks ago a had an epiphany. I have a couple of extra baffles and end caps under the work bench. I cut the inner end out of one of them, and the outer end off of the other. I then welded the two together basically creating a baffle that is now twice as long as the original one. I was pleasantly surprise with the new sound and it was also a bit quieter. I then had it dyno'd again and found that both hp and torque went up almost 4 points each.

So, if you're not satisfied with your mods to the baffle I would suggest trying my mod.

 

I was up at FM with a buddy who was getting a 98" done and threw by some thoughts to Jamie. He said his experience with the newer baffled pro pipe was to cut off the end plug to reduce the TQ dip. He said it would be a bit louder than stock but not much more so. If anyone has tuning experience with pro pipes,I bet it'd be Jamie. Not wanting to have it much louder, I just opted for the 1" hole (quite honestly by just going half the size of the cap) and had it tuned that way. I know some things from my experience. It is a bit louder with the 1" hole than stock and the decel sound is not as deep. Their is no pronounced TQ dip with the drilled 1" hole (see chart attached)as much as it more like a plateau line. I never was a math wiz but my thinking was that (5) 3/16" holes would equal about the same opening area (15/16") as one solid 1" hole . Oh well, no diff on the butt dyno and the bike runs/sounds very nice. If I go with some TB porting/tuning next winter I'll have it retuned in this configuration .....

 

anyone have a sound clip of the baffle mod?

 

This is what I found. I drilled a 1" hole in the center end plug as suggested. Sounds nice with less decel pop and pulls a little harder 3500 rpm up.

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Years ago we used to work with those pipes, quite often, while dyno tuning.
We found that the OEM baffle(right pic)with a 1" hole drilled thru, showed almost all the torque of the untouched baffle and almost all the hp of the hot-hot baffle.
If you looking for more torque, block off the some of the holes, with a band clamp.
Scott
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PALMER BROS.
HILLLSIDE MOTORCYCLE & MACHINE
5225 S. Main St.
Munnsville, N.Y. 13409
315-495-6650
www.hillsidecycle.com

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Lonewolf176
Road Master
Garage is empty, add now
Join Date: Sep 2007
Location: Vancouver Island B.C.
Posts: 1,189


Quote:
Originally Posted by troop
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.

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.
Attached Thumbnails

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TheNowhereman
Join Date: Feb 2008
Location: California
Posts: 1,090

I think you got it wrong.
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.
Better yet, knock out the butt plug completely, then pick up a Quiet Riot baffle and bolt in in at the last set of perforated holes.
This will give you the best of both; great power and great sound.
The Quiet Riot will set you back about 120 bucks but, you'll never want another pipe for your scoot.
Unbelievable torque and a nice rumble when your cruising around.
Open the throttles and the baffle opens up to a straight through race pipe with lots of power from 2000 to 4000 rpm, where you need it the most.

 

Figured it out. I took the area of the larger primary 1 7/8" pipe which is 2.7612" and drilled a hole to equal that amount when added to the (36) 1/4" holes in the baffle which add up to 1.7672". A 1 1/8" centered drill hole on the plug is .9940" and when added to the (36) 1/4" holes (1.7672") in the baffle they equal 2.7612" - same as 1 of the primary pipes. Bike runs great. Pulls good at 2000 rpms and starts to pull harder at 3500+ rpms than without the mod. I packed both baffles with stainless muffler packing too for a deep sound. Very Pleased with performance and sound.