TRD/ Magnuson 4.0 Supercharger Tips, Tricks, and Mods

That's the one.

 

So right now you have no cats at all, one resonator, one muffler, and that is it? I'm not surprised you have a rasp no matter the equal length-ness..

Restriction is not the thing you need, although that is often used for a substitute for for chambers and mufflers. Each time the exhaust goes through a chamber or even a bend in tubing, no matter if it is a cat, a muffler, empty resonator, packed resonator, glass pack, or even a helmholtz resonator, it causes reflections in the sound. When these stack up you get wierd noises, when they are equal and opposite you get noise cancellation.

You could look into a helmholtz resonator setup that you could calculate and make, and even tune out that frequency. Or if you don't want to go scientific, then adding anything, most especially a cat, or another resonator would probably do the trick. I'm curious of the science on resonator placement myself... some OEMs like dodge/ford put a resonator in front of muffler, GM does it after right at the exhaust tip (often seen on a tahoe, suburban, etc). Also as far as I know, a Vibrant 'ultra-quiet' is just a small packed straight through muffler... not anything fancy, and there is also no difference that I know of from a resonator to a muffler, there are just different sizes and different perforation designs and different packing material.

Looks like Magnaflow is on the Helmholtz resonator bandwagon.. they now offer a muffler and exhaust system that has a tuneable helmholtz resonator built in. They call it the 'overlander', not that I agree or like that designation... but I think that word sells product these days...

 

Right now I have 2 vibrant high flow resonators. They are located right after my y-pipe and they flow into my muffler. I was curious if I should swap out one resonator for a cat.

 

nope.

 

I completely understand your troubles trying to get all the RPMs sounding good without resonating. And it’s tough to do when you delete all 4 cats and have LT headers and equal high flow ypipe. Minimum 2 large mufflers after ypipe. Or some people do keg and small resonator. But just after ypipe is where the problem occurs and where you need the resonators/mufflers. Which is good cause it’s definitely the least restrictive area of any exhaust setup.

 

I believe you need some additional sound reflection systems. I don't know if you have room for anything in front of the resonators, if so that is an option. But don't think that the muffler has to be the last thing in the path. Do you have it cut off after the axle? or does it still have a tail pipe? Not sure if you still have a stock spare tire, but if you can, build a tail pipe with some bends and put a resonator or smaller muffler, after the axle, and rout it all the way to the back, tucked up nicely. A bottle style resonator, or a small glass pack, or for that matter even a helmholtz resonator back there would probably work wonders. Or you could put a helmholtz tied in right in front of the first vibrant, and run the pipe parallel and along side both resonators.

Do some research on helmholtz exhaust resonators. They are basically a open chamber that is tapped into the exhaust pipe, but doesn't connect on the other end. Empty pipe connected to the exhaust but doesn't see any 'through' exhaust flow. The volume of said pipe changes the helmholtz resonance, smooths out pressure pulses, and would also be a sound reflection point. Almost all exotic exhaust systems use one in one way or another. Even the factory intake manifolds have them, chambers tied into the flow path, but doesn't see flow. These change the sound without changing flow.

 

@DocME was this the fruity tone you were mentioning? I guess everyone should start compiling more data to get this tuned.

 

Yeah it’s the same one. I tried a lot of approaches along with Roostfactor. After he recommended the keg muffler and I tried it, I haven’t looked back. I am entertaining the idea of something different for slightly better clearance under my FJ now that I’m three linked. Been dragging the muffler a lot too. Also I’ll lose my ultra quiet resonator when I install my rear sway bar.
@racebug68 is correct, chambers that allow the sound waves to bounce around are what is needed. That new magnaflow option is new to me. Looks interesting. I would hazard a guess that it does pretty well at reducing the buzzing noise, but not 100% like the oem style of muffler.

 

On a supercharged engine if you make the exhaust flow more you will lose some psi of boost right? On my TRX I changed out the super restrictive exhaust manifolds for some shortys and kept the cats and seems like it’s reading less boost but don’t remember if that’s normal or not

 

Less boost with more flow is usually a good thing. More power+less boost=more efficient.

 

@TRON @racebug68 I have no room in front of the front resonator as that is where the y-pipe connection is. I had to chop the tail pipe off because the icon rxt springs made that happen. I also do not have a spare under there due to the hammer hanger kit (stabilizer bar). So I wonder if a muffler - resonator - rear muffler would then do the trick. I never thought of multiple mufflers……thanks boys!!

 

OK, for sure build a tail pipe, and put another chambered something in there, resonator or a bullet type race muffler, or whatever... and if you can put a few slight bends in that piping, it would help. rear exit, inside the frame rails, at the back bumper area turned down and cut so it doesn't become a hang up if you are backing up, or dropping off a ledge... abandon the side exit thing like oem had.

I personally would put a v-band clamp at your connection point to the existing system, so you can unbolt and change it if needed without having to un-do the entire system.

That is what I'm going to do, custom y-pipe, not exactly EL, but close, true merged 2-1 collector, v-band to 2.5", then flex coupler, then ultra quiet resonator, then magnaflow 'overlander' with the hemholtz, over the axle to another v-band, a bullet resonator and a 3" tip, turned down and cut flush to the bumper on the inside of the frame rails. Main tubing will be 2.5" for me though, and 2" Y-pipe with stock secondary cats. long tube headers, no primary cats.

 

I do have a v-band at the end of my y-pipe. It then goes to a flex pipe. This is right before the 2 resonators. Here is a pic prior to the resonators.

 

I think I’ll try a muffler to a resonator to my rear muffler. I’ll also do like what you said and see what can be done for a better tail section

 

I would do resonator right after ypipe then two larger mufflers for best sound. Even straight though to chamber. Definitely need exhaust output out original location. Anything less is not controlling all RPMs.

 

Awesome, thank you.

 

that is normal. when i removed manifolds for headers flow went up, boost dropped.

 

i do respect your view, i want to watch and learn. i honestly wouldnt mind louder if flow is correct. im considering fuel tank relocation for side pipes.

 

Maybe I’ll try what your doing. Keep my front vibrant resonator, then to this (link below) and then to my current rear muffler. I’ll see what I can come up with in terms of the tail pipe.
https://www.magnaflow.com/products/...-universal-performance-muffer-with-ndt-3-inch