Looking to build a full 3" turbo back exhaust and I would like some advice on components. First, the car is 97 Miata with an FM Butterfly brace. I'd like to open up the exhaust as much as possible while keeping the sound nice and stealthy.

I am looking for the largest straight through style muffler that can be mounted diagonally, paired with a resonator and a high flowing metal core cat. After looking at some setups posted here on Miataturbo.net I spec'd out the following components:
Magnaflow 5" x 8" x 14" offset/center oval muffler
Magnaflow 4" x 14" round resonator
Maremont metal cat

I am not married to any of these choices, so feel free to suggest better/different parts.

I have lots of questions too Like... can I go bigger on the muffler and still mount it diagonally? Are the inlet/outlet locations optimum? Any benefits from using a round vs oval muffler? Any better resonator choices out there?

y8s, Turbo Tim, Buller... Buller, anyone, anyone?

Anybody care to comment about fitment issues with the butterfly brace? It has some adjustability, but I am not sure how much.

 

Some additional info to help guide the discussion...

stainless? yes!
polished? doesn't matter.
straight through? of course.
internal louvers? no way!
freeway drone?
dampening materials that won't burn up or blow out? This sucker better be the last exhaust I have to buy.

 

Nice choices. I would just go with a Carsound/Magnaflow cat and save $100.
www.muscleexhaust.com has great Magnaflow prices.

 

If you have money to spend and you want something that will fit and sound perfect, give Jason at Enthuzacar a call. I could not be happier with how my 3" stainless catback sounds. It's nice and deep without ever being obnoxious, and only a little bit louder than stock. I NEVER get looks from police officers. He also has the Magnaflow cats, $70ish for the standard and $110ish for the metal core 3" cats.

 

^^very nice exhaust system...not to loud either but im not to sure if the enthuzacar exhaust system is straight through?

?...is the magnaflow mufflers taper on the inside? or is it 3in all the way...maybe considering this route!!!!

 

if you email the guys at magnaflowonline.com (my old site) they will give you deals.

 

I use the 5 x 8 x 14 magnaflow on my car, it was the largest volume muffler (therefore quietest) I could fit diagonally. No resonator, vibrant metalcore cat (recently I've been getting different cats from vibrant though, same PN but different cats). No drone on the highway or anything bad like that, haven't tried it on a car w/o turbo yet though. I think it's quiet which I wanted, love it. I've done an MSM turboback with the 4x9x18 magnaflow and it was slightly lower, as it has a slightly less internal volume. center inlet, offset outlet on both of those.

This one was too loud but Paul still runs it.



Y8S fit one of the 22" magnaflows on his car, but it's more perpendicular to the car like the factory muffler. I tried to fit it diagonally but there was no F'in way.

I tried to fit different round mufflers but found the 5x8x18 was the best fit/quietest canister i could make as straight as possible.

Turbos are off now; old Enthuza 2.25" non-resonated is on the car now and it sounds like ***. Very ricer-ish, raspy, buzzy, droney on highway. But it is old and I think enthuza switched canisters at some point. I'm going to install my exhaust with the OEM exhaust manifold and hopefully be able to drive it w/o being embarrassed.

As far as resonators (again I didn't use one and there's no drone with the turbos), the largest I could easily fit on my exhausts is a Vibrant 12" piece, the one you can see in the above picture. You can also see the (old style?) vibrant metalcore cat in that pic.

EDIT: If a mod can make that pic show up smaller, that'd be sweet. I forget the code.

 

If you want to come straight out the back, the typical 14" can oval muffs will fit. I've got a no-name turbo style muff stuck up there. I flanged it right after the diff so I could easily swap out muffs/pipes. Photo below is with a straight pipe section in place.

 

Fwiw, I had Jason fit a Magnaflow muffler on my 3" enthuza exhaust. Cant wait till it arrives!

 

if you dont care about polished it would be cheaper but just as good to use
http://www.magnaflow.org/index.asp?P...OD&ProdID=4147
same muffler as you listed $92 shipped
http://www.magnaflow.org/index.asp?P...OD&ProdID=4325
again same as you listed for $85 shipped polished is the only way they carry this one
and one of the cats WOT recommends...and you should be good to go $70-80
$252 appx...they are all high quality components...
that should last a lifetime...make sure you use SS mandrel piping, you will regret it later if you dont...good luck in your search

 

thats awesome, thats what i was planning in production, all my pipes are ending at the same place, right after the axle, and then i can just add any type of muffler...it will bring the lead time way down if i keep premade pipes on hand and then just add the muffler and affiliated piping that the customer wants to use...it made sense to me, im glad to see someone thinks alike

 

Budget permitting - I highly recommend Vband flanges vs. the flat bolt type IF there's a need for swaps. OTOH the 3-bolt 3" flanges are VERY inexpensive, about 25% the cost of a vband junction.

 

dont buy directly from magnaflow

i promise, I used to sell muffler to you guys before in the past from my site magnaflowonline.com and rev2red.com.

I don't do it anymore, but www.magnaflowonline.com is still active, it's still run by and old friend, and he will give you some of the better deals. Magnaflow has a MAP policy (minimum advertising price). which means, if you sell magnaflow "legally" you cannot advertise a rate lower than what they tell you you can. This means, every site out there will have the same price for magnaflow stuff.

 

thanks for the advice chief...ill check it out, i need to order some stuff this/next week to start my builds...
i found some for like $30 ea. but they use mild flanges and SS clamp......i offer both, obviously its more if you want to use vband, but it much easier and safer to use them vs 3 bolt flanges...makes muffler swapping a joke

 

I got my magnaflow on ebay, lowest price i got.

 

your choices are fine. I second the V-band flanges though. so easy to install and you get lots of post-install adjustment range. worth the cost. you can do the whole post-downpipe section with 2 minimum (one at the dp, one at the diff) but you may want another one in the middle if you have that butterfly stuff or a removable cat.

 

possibilities are endless, money is the only restriction IMO

 

at least call www.performancepeddler.com

they are magnaflows largest distributor/wholeseller of their products, they get insane prices.

 

i checked, they are near ebay prices for new mufflers...
$55 shipped for the 4" round polished SS muffler
about $110 from magnaflow directly...WOW...thatnk Brain, i think ill buy them all from them...

 

Thanks for all the awesome replies guys!

And yes, Braineack, I had planned to order the Magnaflow stuffs from performancepeddler. I bought a bolt-in stock cat from them awhile back. Awesome prices, good service, and prompt free shipping.

I like the 200 cell metal core Maremont, but it will take a month to get one, there's not allot of info available, and its twice the cost of a 300 cell metal core Magnaflow with nearly identical claimed flow specs.

link
59929 Mangnaflow ultra high flow cat (couldn't find on MF's site)
59959 Mangnaflow high flow compact cat

I'm waiting to see how whaaamx5's exhaust looks and sounds as I am seriously considering sending this stuff to him to have it welded up with nice mandrel bends.