How would you do a custom exhaust for an FC? Looking for specifics, specifically parts, what type of muffler you would use. Just trying to get ideas for how I want to do mine.

 

Whats your power goals?

 

Oh yeah, I did forget to mention this is a non-turbo FC. So basically just looking to get anything I can out of the engine.

 

with an n/a engine, i wouldnt use piping any larger that 2.5".

if you check out the N/a performance part of the forum... theres some good exhaust info in there.

 

I already know what piping to use. What I guess I'm getting at is what you would use for mufflers and what style would you use.

 

Well, with an NA my goal would be to not make it sound like complete garbage.

Will you be running a header? And I assume since you are in CA, you will have cats?

 

Use a heat-wrapped header, a nice high quality high flow (single) catalytic converter, a high quality resonator, and go for single exit. I'd personally use a borla muffler because I like the way they sound, but I hear good things about twin loop mufflers also. Now, to prevent the car from sounding like total ***, go for a good thick mild steel exhaust piping with mandrel bends. If you can weld, this works out great for you. Check out mazdatrix.com for exhaust flanges and gaskets, and see if a local exhast shop or parts store can get you some u-bent 2.25 or 2.5" pipe. Choose and pick your brands as necessary to fit your budget.

Do not use a glasspack muffler. The figerglass packing will melt and then solidify, causing an annoying rattle.

 

i'd cut a hole in the p/s fender and run the exhaust straight out. then i'd pull up to cops and rev it to 8k, but that's just me lol.

 

Hm... If you weren't going to be taking it in the *** for shipping, I'd say why not pick up my RB, REV TII (though minus the DP and pre-silencer. Y-pipe and dual mufflers, only. The rest are on my single-sided, Turbo-back, setup).

As well, it's also the same setup I recommend, if you were going to purchase one, straight-away:

Racing Beat REV TII Exhaust system

All you'd have to do is get the RB long headers and a cat (air-pump compatible, since you're in the land of the fun ***** )

 

Ive been researching for the past three months on how to build an ideal exhaust for my NA S5, heres the link to my thread:

https://www.rx7club.com/naturally-aspirated-performance-forum-220/suggestions-s5-na-custom-exhaust-build-923362/

and heres another link to one of my forsale threads, just in case your interested:

https://www.rx7club.com/west-sale-wanted-classifieds-195/motoria-3-resonated-cat-replacement-pipe-923647/

 

Great links, bro!

+1 to this guy. Listen to him; he seems to have his **** together.

 

knowledge is power, fo sho ;p

 

+1

 

Well as far as I'm concerned, headers are not an option right now, they aren't legal anyways, so until I figure out how to bypass that, I'm sticking with the stock manifold and cats, for now, however the cats will be replaced if needed, most likely I will replace the stock main unit and modify the cat section to all welded together to minimize any chance of an exhaust leak, this also let's me modify the cats themselves so I can open them up from what they are now, to 2.5 inches that I will want to go to.

The plan right now is to use 2 round style magnaflow mufflers with a tip, since this is a dual system, should the dual system be a 2.25" or a 2.5"? Since this will be going from a single 2.5" pipe to a single 2.25" or 2.5". What's the best option here?

 

Well, it would seem to me that if you're going to be using the stock manifolds and cats (air pump), then you shouldn't have any problems.

As far as the legalities in using headers goes, as long as the headers have what's called a 'CARB EO number', you'll be fine to use them, legally.

CARB stands for 'California Air Research Board' and the EO (Executive Order) number is one that's issued to emissions parts that certify in California to meet a certain criteria of smog/ emissions control.

Basically, if the parts got a CARB EO#, it's legit to use in Cali and the several other states that have emissions laws so strict that you can't buy a can of baked beans without a permit.

As far as piping-diameters go, I would keep in the2.25" range. Alot of people think that when you refer to a diameter, it's combined, since it's dual, but actually what you're referring to is the SMALLEST diameter, in the system.

Here's what the governing body has to say about aftermarket parts in California:

"Exempted parts are add-on or modified parts that have undergone an ARB engineering evaluation. If the part or modification is shown to not increase vehicle emissions, it is granted an exemption to emission control system anti-tampering laws. This exemption is called an Executive Order (EO) and allows the modification to be installed on specific emission controlled vehicles. Every Executive Order part or modification has an assigned number that can be verified by Smog Check stations, BAR Referee stations, or by the ARB."

... And if yoo cahn't pass smog, Yool be bahk!

Basically, if your air-pump and O2 sensor are in good shape (i.e. you can pass smog, as you sit, right now), then fitting the proper exhaust will not compromise your emissions, at all.

LOL. < Insert broadcaster's voice, here. >
For further information, please visit the California Air Research Board website at: http://www.arb.ca.gov.

As well, the RB exhaust is pretty much what you're talking about wanting to use (save the fact that mine's got black muffler's instead of blingy chromw).

I would read the thread by 'CanyonTougeFC3S.' It'll help you out.

 

for me personally i would go with 3 borla XR1's, 1 as a presilencer and 2 where the stock duals are with turndowns. for an n/a i would go with a 2 1/2" presilencer and main piping and 2" duals with turndowns at the end of the tails.

i'm getting a bit tired of all the singles that sound ricey. the borlas have a nice F1 car tone and quiet the exhaust down quite a bit as well as flow well. to buy the mufflers is about $400 and to have it all put together would probably be about another $300-500 for a nice looking and sounding exhaust system. for turbo cars you just start with larger diameter piping depending on your power goals. sure it's a little expensive but you probably won't get tired of the sound after a month of driving daily and in california sound and looks can get you profiled in a split second.

 

Most singles sound like **** because they're on some BS piping, run from the OEM manifold.

My old 86 GXL had solid 2.5" run off of RB long headers and it sounded awesome. not high and tinny, but loud, pronounced and DEEP (Running it through an A'pexi was a good thing. only mod I made to it, after that, was putting a Magnaflow 'Turbo' muffler, inline (it decreased back-pressure the higher the internal pressure level).

It worked great! No loss of power and no MASSIVE notice in the db range (WOT was a different story, though).

If I knew how much the RB weighed, I'd offer to ship it, fairly cheap, but I know that it's heavier than my 3" DP-back system, by a LONG shot.

He could go cheap, or expensive, but I think he's going to get what he pays, for, ITLR.

 

it's not just the sound but the cars just don't look right with singles on them. i've always preferred the looks of a nice dual. there is some manufacturers who still make duals like RB but this thread is about custom exhausts.

 

yeah having an open exhaust hole in the bumper sure doesnt look too appealing but yet again, correct me if i'm wrong, having dual exit exhaust slightly reduces db noise level compared to a single exit exhaust. Especially on a NA Rotary Engine.

In my opinion, go with some sort of headers because the stock exhaust manifold makes the rest of the exhaust sound like ****.

 

Agreed. I think RB headers, Y-pipe, custom 2.25 piping and a pair of decent-looking muffs.

Good ideas.

 

they can radically reduce noise if you can squeeze in some more smaller mufflers between the Y-pipe and the rear mufflers. the Greddy power extreme(corrected) exhausts used a total of 5 mufflers in the exhaust and had a nice quiet tone through the whole RPM range, arguably quieter than the RB duals. but the more you muffle the exhaust the more possibly you rob power so 3 good working mufflers is probably a good goal.

i'm not a huge fan of the stock turbo catback sound but i have done some swapping of my exhaust and the stock S5 turbo catback actually flows almost as well as an uncorked single 3" up to ~325WHP. so for the sake of power, people who are swapping out their exhausts, it's mainly just in your heads. the shops that claim that their exhausts raised power levels by 15% or 38 horsepower for example i would say, probably removed the cat and didn't correct for the difference in boost creep that was adding more power. for an n/a you're just making gobs more noise for maybe less horsepower than you can count with 1 hand. so that said, for me, if i'm going to ditch the exhaust it would be for sound quality, not for power(though i wouldn't suggest going smaller on piping diameter or you will lose power, small amounts can be gained going larger but at the cost of sound quality).

 

yup im doing something similar to that: im using a RB presilencer into a magnaflow into a titanium resonator but w/o a cat

 

If it were me, mild steel v bands with mild steel 14ga 2.5" piping, single exhaust, dual 3-4" tips, no mufflers, no resonator, no cats.

Loud, cheap, hellfire.

You're in california though so you're better off leaving it stock. Lol.

Smog police cut yo ***!

 

+1 hahaha i was totally gohna do this too but people knocked some sense into me lol

 

unfortunately that was the main reason for the testing of the stock catback, in cali anything that doesn't look stock will at least get you a fix it ticket if you're lucky(exhaust wise).