I just spent the last couple days fabricating a 3.5" exhaust for my friends FD. He just swapped to an EFR 8374 and its a little loud for my taste (as in will attract unwanted attention). I'm doing a nearly identical setup in my car and will be fabricating my exhaust in the next couple days. I want to add in a resonator now rather than modifying stuff later.

What are your guys experience with resonators? What companies work good? I'm assuming most won't last more than a couple years and will be need to be replaced every now and then?

It's for a 3.5" system made of 304SS

 

gonna add some videos and pictures to spruce up the thread




https://www.youtube.com/watch?v=E03w6-0xde0

 

looks like some of the options that pop up are:

Borla XR-1, available in 3.5",seems there are lots of types, and some of the prices are up into the 300-400$ range which is alot considering other types sell for 100-200$, but they seem to use steel wool packing instead of fiberglass, might last longer.

Raceing beat, not available in larger than 3",

Vibrant resonators, Aaron Cake said he had some success with their "ultra silent" style resonators however these are not available in 3.5" they do make a traditional bottle stye resonator in 3.5". Vibrant Performance ::., very cheap at 100$, need to look into this option more.



the borla's seem to be the most recommended but the type/part number isn't usually mentioned

 

When I rebuilt my 3.5" exhaust I used a Vibrant Street Power 3.5" muffler.

Vibrant Performance ::.

It isn't a presilencer in my exhaust, but what I noticed is that it is 100% stainless with stainless packing and quite heavy.

Its pretty cheap @ $150, has a 2 year warranty and is 3.5" in and 3.5" out. I would definitely try it as a presilencer before any other muffler I have heard of.

In my experience, because the 3.5" exhaust diameter is so large- straight through mufflers and presilencers won't take off as many decibels as you would like, but they definitely give it a deeper, less annoying tone.

Here is my 3.5" turbo back with just the 1 Vibrant Street Power at the end.
https://www.youtube.com/watch?v=NmnT...ature=youtu.be

 

At 9" wide there might be an issue fitting it ion the midpipe position. I'll have to measure it out to see if its reasonably possible.

 

maybe something more like this
Vibrant Performance ::.

 

grab a magnaflow. stainless packing and a fiberglass packing behind that. deep low sound, lifetime warranty and top notch quality

 

I have a 4" Borla XR1 and I believe all larger Borla's have a sort of deflector or honeycomb in it to help deflect the gas/noise.

The Borla replaced a 3" magnaflow straight through resonator which burned up after about a year of use. I remember getting it and it sounded solid when knocking on it. Knocked on it again when I switch to the 4" and it was definitely hollow.

We also put the borla on the back of a 3" straight pipe exhaust (no welding just slipped it over) and it dropped the sound by IIRC 6db measured from an app on my phone.

 

Strange. Thats the first one I have heard blow out. Might of had other issues like high egts. Lots of 13bs and 20b cars running the magnaflows for decades with no issues.
The borla does not use a fiberglass behind the stainless mesh like magnaflow does. If you compare a borla to a magnaflow in sound the borlas have a ting to them unlike the magnaflows where the fiberglass might be absorbing any excess resonance.
Fwiw i have a borla system on my rx8 also and it sounds good but has a internal rattle... they dont offer a lifetime warranty to cover it like magnaflow does

 

I bought a 2nd hand midpipe for my FD that had a Magnaflow SS muffler as a presilerncer.

It was completely burnt out and hollow. Weight reduction!

 

Just about any size, correct internals, rebuild-able.

Ultra Lightweight Racing Mufflers - Coast Fabrication

 

You could buy the revolution 90mm mid pipe which is 3.5" already made and cost $650 USD
Or the one with a cat aswell for 900
USD
http://revo-tune.jp/catalogue/detail.php?id=233

 

Grass Roots Motorsports did dyno testing of the Vibrant Resonator - it ate 7.5 HP on their test car (Honda I think)

I have one on my FD, would like to replace it and the RB Twins with a couple of Coast Fab racing mufflers.

 

Any idea if that was their regular resonator or the ultra quiet?
It's a straight through design so I can't see it being much worse than any other straight through resonator

 

Don't remember - you probably could find it at the GRM website.

 

I've had pretty good results with Magnaflow. They seem to quiet things down more than others.

 

I went with this http://vibrantperformance.com/catalo...oducts_id=1703because I had a easy source and its only 100$
That's cheap enough that if I don't like it or when it burns out I can just replace it with something else.
Exhaust is all fabbed up and tacked together. Once I have the resonator I can swap it in place of that straight pipe.




I didn't like how my midpipe section turned out so I redid it.

 

I am currently using a 3.5" DP > 3.5" MP > Vibrant Ultra Quite 3" > 3" HKS Carbon Ti with dumped waste gates. Sounds amazing with very little drone while cruising. Of course it is stupid loud under boost. I can actually have a cell conversation cruising on the freeway without annoying the person on the other line.

 

Here are the vibrant resonators, I ordered two one for my setup and one for my friends, curiously enough they both have the same part number but look and are designed considerably different. one looks like the link and the other looks more like their ultra quiet series but that series doesn't have a 3.5" option.


the one that looks more like the ultra quiet one has more holes in the inside but it looks like a little shoddier workmanship. the backing also looks like a white fabric with some wireish stuff.


the other one has less holes but has some steel looking wires poking through the holes so I assume this one has a stainless style filler instead of fiberglass.



For less than 100$ how can you go wrong.

 

Is this an internal wastegate EFR system, not one of ours by chance? I have sent a lot of turbo manifolds/turbo only setups up to Canada..

 

Yes it is an iwg 8374. I made everything myself as I'm on a lowly college student budget. I believe my manifold is similar to the positioning of yours but it is a little different.

As far as the resonators go my car with the resonator installed idles quieter than it used to on non sequential twins with the same catback. I can't comment on the sound when pushing the engine as I still need parts and tuning before I can boost this thing.

I plan on trying to get some before and after sound clips of my friends car when we install the resonator.

 

No worries

Has this car been street tuned yet? ( or better yet dyno tuned ) ?

 

None of the above, I got it driving on the stock fuel system so I could make the local season opener car meet. I have to install my new secondaries and my wideband when it comes on then I can start street tuning.

This is on a power fc

 

You will pop the motor on the first pull with a stock fuel system. You will not be able to hold low boost with a 3.5 inch exhaust.

 

without a doubt at no point did I even think of doing a pull on the stock system, I just used it to drive around a bit using my foot to keep me out of boost. I've got an old set of 1680 secondaries that I will be installing to give me enough fuel for lower boost settings.

The system is 3.5 inch downpipe and midpipe. The catback section is still 3 inch. I plan to build my own catback down the road once I have the setup tuned better. I'm actually very interested to see how well I will be able to control the boost at low settings with the current exhaust as compared to when I go full 3.5 inch.

The engine is also stock port so it might boost creep a little less up top compared to a street port, at least that is what I'm hoping.