JFR Equal Length Y-Pipe for 2nd Gen Tacoma, T4R, & FJ Cruisers

I think they use carbon steel in the construction of the membrane frame. I think. it might account for the oxidation.

 

The exhaust is probably 409 stainless while the mesh is probably a 300 series.

 

So I did a bit more experimenting with the dual Flowmaster 40 knockoffs. They HAD a significant drone in a fairly wide rpm range (at least 500 rpm) so I said what the heck, either these muffs are coming off or being modified to see if I could eliminate the drone.

Here is the concept:

Two identical sound waves hitting each other at the same frequency will amplify sound and if the same frequency is introduced 180° out of phase it will cancel the sound (how noise cancelling headphones work).
So I cut a hole in the first chamber of each muffler and made two different sized 3" caps filled with stainless wool and a mesh screen to keep it from blowing out.
The idea (non calculated) was that since my exhaust merges at the y-pipe then splits back out to dual means that each muffler is "seeing" the same exact pulse at the exact same time which ultimately amplified the sound.
By changing the internal volume of each muffler and creating a sort of "damper" for each, the sound waves would be altered so they are no longer symmetrical. This theoretically would change the resonant frequency of the system which is a primary contributor to drone.

I did a quick test last night and seriously cannot believe the difference! The truck is seriously quiet now! I am going to take it a bit further today and make tailpipe lengths different to further alter soundwave exit but initial impressions are very very good! Here is what I did:

 

You are becoming an exhaust wizard.

 

Thanks to you guys! I'd never be here and able to play without your support.

 

I’m just waiting for the JFR full exhaust to come out

Even though I am very happy with my banks exhaust currently.

 

Got a Dyson eh?

 

Nice! I like it. There's something about just going for it and hacking up new equipment that brings a smile to my face.

IN for video clips....

Also, per our earlier talks, I ordered a new custom length muffler from that one outfit. Then I did a little more research and it turns out they're horsepower killers! Hopefully I can work with them to use a different perf core, but if not that one's going to be DOA.

Lastly the 70 series flowmasters have dual helmholtz chambers.....just saying. I could probably use one more muffler laying around.

 

Yeah! these are Totalflow 409 stainless 2.25" in and out. Around $40 apiece on Amazon so I wasn't too concerned about price for testing purposes. Totalflow doesn't make any 3 chamber Flowmaster knockoffs or I might have tried the 50's.

I know these chambered mufflers are supposed to kill flow as well which is one reason I went with duals instead of a single. The other reason being that each muffler only has to silence half of the exhaust instead of a single muff doing all the work. Once I get done with the tail section and drive around a bit I will provide more info and possible cheap sound clips.

Bummer on the "flow" killer! Maybe you can call and retract your order if they haven't started on it yet?

 

I second this

 

I’m with them

 

Ditto

 

All this experimenting you’re doing is a lot of work. It must be exhausting.

 

I'm in the process of installing a replacement A/C clutch. Reading the blogs there is mention of three new spacers. How critical are those new spacers? May I use the existing spacers; my A/C clutch did not arrive with any spacers.

 

Think you meant to post that in a different thread mate.

 

Thanks!

I think ultimately I will have to design/build/test my own muffler or I should say "silencing system" to target our specific needs.
Hmmm

 

Sounds like a plan, add it to my order

 

You're nearly there!

 

I prefer the term "supressor" or "can"