Muffler inserts for side pipes?

[shelbypruden]

I am building a 289 kit. I am looking at these inserts:

https://www.summitracing.com/parts/sch-42530

They are supposed to reduce the sound by 9dB each. That is a decent amount since decibels are logarithmic. I plan to weld one in the ends of each of my 289 pipes.

What if I welded them in the side pipes at the front? Where they bolt to the J-pipes. Too much heat there? Too much restriction? What are the downsides of placing them there?

214864

[lasse2]

I am building a 289 kit. I am looking at these inserts:

https://www.summitracing.com/parts/sch-42530

They are supposed to reduce the sound by 9dB each. That is a decent amount since decibels are logarithmic. I plan to weld one in the ends of each of my 289 pipes.

What if I welded them in the side pipes at the front? Where they bolt to the J-pipes. Too much heat there? Too much restriction? What are the downsides of placing them there?

214864


I'm assuming you are looking at those because they are small and could potentially be installed without cutting or welding. I'm a little doubtful that you will get 9db out of a single insert that size but I'm very interested to hear if you do. I have a Coyote in my 289 roadster and it was earsplitting with the stock pipes. I cut the pipes into three sections and added two of these in each side pipe:

Dynatech Auger-Style Muffler Insert 3" x 11" (https://www.jegs.com/i/Dynatech/329/776-24302/10002/-1?gad_source=1&gad_campaignid=17338879807&gbraid=0AAAAAD6OBRGyBpiNBx1O30-kNqKxUXCN-&gclid=Cj0KCQjwjJrCBhCXARIsAI5x66VnpoHP1BZ5SBle-0jaAtYmYKDJlXQKT3q8U33XAoTwOrcGPWkFX2QaAmzUEALw_wc B)

I started out with one in front of the glass packed portion of the pipe and decided that it was still too loud and added a second behind the glass packed section. The result was a significant reduction in sound but I'm not sure it would be 9db. The idle is much more neighbor friendly but once you get on the throttle it still roars. I'm certain that I've introduced some restriction to the flow but there is more than enough power and I'm not concerned.

If you go with those, I would lean towards installing them closer to the flange rather than at the end of the side pipe or perhaps on both ends. I don't think heat will be an issue.

[brewha]

I’m running Car Chemistry 2 disk inserts with no plugs or packing. It has dropped the db’s about 5.
They are pushed into the ends of the pipes and are held in a single rivet or screw. They give you 2 different plugs that can be welded on the ends or can take exhaust steel wool packing in between the 2 clips to reduce it further
Several others on the forum run them too. They have little or no effect on horsepower per tests on their website. Carchemistry.com
The new exhaust pipe from F5 are tinny sounding when new but that changes as they get older. If you have a stroked motor or high compression heads, the exhaust noise will be quite louder. If you cut ends on the side pipes and angle them down more towards the ground, it will tone them down also.

[shelbypruden]

Great info, guys. I am considering this insert in both ends. If the reduction is not enough, my plan is to cut down and weld flanges on the side pipes. Then I can install standard glass pack side pipes like cherry bombs, purple hornies, etc...

[MikeHolt]

I opted for the Lobak inserts (I believe they are now Patriot Muffler inserts on Summit). I cut open the exhaust, welded them in and then turned the exhaust tip down about 10 degrees.
Gave a decent sound and took the monotonous drone out of the left ear at highway speeds.

[Rdone585]

I put Vortex cones between the collector and swapped the (blown out) glass pack with a twister muffler. Then I purchased turn down pipes for the end that can be adjusted to point where you want them to. That combination greatly reduced the loudness of the pipes down from over 118 dB to less than 105 dB. That measurement was at 50 ft in a parking lot, full rev. Just be mindful that turning down the tips too much can make a big dust cloud. I later had them ceracote covered and they are holding up well. Also, I'd like to add that my later engines (408W and lastly a 408 Dart block), aren't as loud as that first one (302). Since the newer engines are nearly twice the power of that first engine, I can only surmise that the cam has a lot to do with the loudness. Hope this helps.