Opinions wanted, Car Chemistry Silencer Insert in Cat Bypass pipe

[KC Chief]

I recently bought a cat bypass pipe. I already have the Fabspeed muffler bypass. It's obviously loud, but bearable for me. I'm looking to tone it down a little. I've seen some people add Car Chemistry Silencer Inserts into their exhaust tips, but I'm considering going another route, and installing one in the cat bypass. I'd appreciate some thoughts on this. It would essentially be a poor man's pre muffler, but I believe this technology is better than the packing in the pre mufflers.

[Elombard]

Interesting, I always thought one of the benefits is you could set it up to be easily removed for a track day. Too bad they are not cheaper, it would be fun to try it. Can you think of any down sides? maybe others will chime in, I have never held one in my hand so cant be too objective.

[DRACO A5OG]

Speedway motors . Com has a cone baffle insert

[Justin@Athens]

I tried it, but installed it after the muffler bypass inside the very end of the tailpipe as you noted above. I couldn't tell much of a difference to be honest with you and I found the muffler bypass was just entirely too loud and had to sell it. Oh, I was also running a cat-bypass pipe from OBX at this time as well.

YMMV,

[Elombard]

I was looking at the Cone Baffle at Speedway Motors that Draco mentioned. Only a 1-2 db reduction claimed?? Hardly seems worthwhile. Maybe thats more than it sounds like.

[DUK]

I built something very similar (aka copied to a t) to that and tried it.

Seemed quieter for a day or two. Then seemed no different. I wish I had had a decibel meter at the time (now I have the app.). I'm sure it was minimal at best.

What I did find that worked and still gives a nice note was adding some Knit Mesh material. I sourced locally from a motorcycle builder. Just wrap it loosely and make sure to wear gloves when handling the stuff.

[VFR750]

I made a slip on muffler tip extension with a CC insert riveted inside. Held on with a bolted clamp. Slips onto my 2-1 muffler exit.

I use this for track days at Lime Rock. to lower sound from 92-95 db to below the 88db limit. I suspect my old muffler has lost most of its internal baffles and is quite loud. The CC insert lowered the sound level, and reduced my hp, as observed by lower terminal speed. I used the 2-baffle design.

It also dramatically reduced the sound in all operating conditions. Idle, cruising, accelerating, everywhere...

The CC insert kit also comes with a plug that can block the central pipe. I tried this and it reduced the sound even more, with a larger reduction in power. I got rid of it.

I think adding one to a cat bypass pipe will definitely reduced the sound. It appears to be very durable, as it relies on flow disruption verses a fiber packing to reduced sound.

[KC Chief]

Thanks for the feedback. I was proposing installing it in the cat bypass because the car chemistry site states that it is more effective closer to the exhaust ports. I think that placement will provide a little needed back pressure as well. I am also no sure about how much space I have in my tip.

Mike, do you have some pics of your setup?

DUK, where did you put the mesh material and how is it fastened?

[DUK]

Wrapped around the silencer and held in place by stainless safety wire.

[Reiver]

I hot rod SBC's and have used the inserts and they tone it down some. The way to get them to really work is to buy some stainless steel cooking pot scrubbers, about the size of a baseball and heavy duty coils (not fine steel wool) and experiment with those wrapped around the insert and wired in place. Takes some time to find the sweet spot between noise/performance but it is kind of fun.

[rwilner]

I installed a pair of these in my 04 mustang exhaust system -- borla stingers. They did nothing...waste of money and time.

YMMV

[rattlsnak]

The 993 crowd has been using them for years in the end of SuperCups. I have had them on two cars. They work perfectly..

[VFR750]

Here is my slip on CC insert. I had to cut slots in the pipe so that the clamp could compress the pipe onto the smaller metric exhaust exit.


Installation takes 20 seconds. Note I had to remove the factory chrome exhaust tip to do this installation. It is not pretty, at all. However, it does the job. The engine does run a little richer with this installed.


Yes, many cars at LRP DEs have gone to this insert to get the noise down to 88 db.

[Upier]

Originally Posted by VFR750

Here is my slip on CC insert. I had to cut slots in the pipe so that the clamp could compress the pipe onto the smaller metric exhaust exit.


Installation takes 20 seconds. Note I had to remove the factory chrome exhaust tip to do this installation. It is not pretty, at all. However, it does the job. The engine does run a little richer with this installed.


Yes, many cars at LRP DEs have gone to this insert to get the noise down to 88 db.

Looking at your pictures, you have the CC incert installed backwards. Try swapping see if you get a performance difference.

[911 Rod]

Bumping this thread as I'm looking at quieting my car.
B&B headers with through exhaust.
Has anyone else tried them?

[RarlyL8]

Adding a baffle to a cat bypass defeats the purpose of the bypass. If you wish to only use that as a muffler then replace it with a pre-muffler. The flow will be much better and the sound more tolerable.
Open headers are obnoxious, add a straight-through free flowing muffler. Baffles are better used to fight drone, any obstruction will disturb flow.