Hey,

I have read several exhaust stickies and threads, however my question is more base on principle not brand names, nor performance. I also have listened to many clips, however every set up is different.

I am leaving the stock cat untouched. looking for diameter of mid pipe, 1 muffler or two? size and shape of muffler? and suggestions for tips?

I would like the deepest, baritone, purrr of an exhaust system.
I do not want loud, popping, high pitched noise.
I am aware that any aftermarket exhaust is louder than stock, but you know what i mean when i say i don't want the entire neighborhood to hear me.

thus far research has told me a larger diameter mid pipe and high quality steel with smooth bends. true or not?

Appreciate everyone help and this awesome forum!

 

I know you're not interested in brands, but I've never heard a better tone than that of my Borla.

The problem with the '8 is that it's not a case of filtering out the 'nasty' and leaving a burbly growl - the basic unmuffled engine note is tinny, sharp and raspy (not in that order!) so there is very little 'deep' to work with.

Glasspacks do a fair job at stripping the crackle out, but they won't stand up to the extreme temperature and concussive assault that is the exhaust of this car, they fail in a matter of weeks, leaving hollow cavities that ping and resonate.

The factory cat, after it has had the ceramic material removed makes a pretty good midpipe - the huge cat chamber forms a second resonator, and the steel is thicker than any aftermarket pipe would be. Thick steel in the cat and factory header keeps the pinging sounds to a minimum, thinner metal can sound tinny right from the engine compartment.
A thin header made me keep checking for a non-existant exhaust leak up front.

...but good luck with your search!

 

I have the Agency Power midpipe, and Racing Beat catback. The catback was on there when I bought it, and you can't beat the price of the AP.

Great sound though. It sounds so nice from outside. The idle has a nice purr to it, and it just sounds good. Never heard anything else in person though.

 

Hey, Stealth thank you for the ery detailed comment, I appreciate your time. And your parallel between dealerships and Schrodinger is golden, (ever seen the movie repo men, you might like that too).

yes i understand with a rotary rather than a piston you get more of a sewing machine than a vroom.

Borla: yes i have heard a few, they sound very close to what i want however every set up is different, and here in Canada that's $900 + 13% tax + shipping and for that price I had better be sure that it will sound that good on my 8. So I'll continue researching until i know it inside and out and make a decision for Harley & I.

Racing beat: okay i will look into it.

However my question still remains: deeper= thicker metal, smooth bends, wide pipes, and 1 large round high quality muffler which then divides to the two tips?

 

I checked out Racing beat BeoDude, and it shows two types of setups that i was asking about, 2 mufflers and one muffler, which will sound deeper? Also I am not in this for performance or racing or lightweight, simply sound. like to hear from you about it. Thanks

 

Point of confusion. Leaving the stock cat means leaving the stock midpipe.

After messing around quite a bit with midpipe and catback combos, IMO that's a good choice for the OP (leaving the stock cat alone). With the stock mid, one can use a relatively aggressive catback and end up with very sweet sound, Greddy (dual small muffler) vs. Racing Beat (single large muffler) for example. The opposite, aftermarket midpipe + conservative catback, also works but is less successful at controlling drone. Under no circumstances get a midpipe without resonators; those things are brutal!

 

You should look at the exoticspeed titan R-II. it's a Canadian product, easily the best looking, sounds fantastic with the stock cat, low and deep in the first 5k revs, doesn't pop unless you really get on it and it's 780 shipped. Can't beat that. Fitment is like a glove.

 

Thats very tough to achieve with a rotary engine.

 

From my research on here - BHR is the best midpipe. Supposedly no rasp and deep tone and the resonator works well with the rotary heat and does not get destroyed over time. Again, sharing what I read in hopes it will help.

 

That replaces his cat though which he said he didn't want to do.

 

They do offer a catted version for more $$$. Not sure what cat they are using now though.

 

Hey, Thanks for all the feedback everyone!
Forgive me however, I am looking at Harley and at this diagram and.....



correct me if i am wrong:
I am seeing a separate mid pipe from catalytic converter. So I am confused by a few earlier comments. Thus far i have decided on one large round muffler, possibly from Borla? new/normal tips specially painted matte lack with super high quality temperature ready paint.

the pipe + muffler + tips i would like to have a larger diameter so she can breathe, is it possible to find a pipe that comes off the stock cat @ 2.25 inches and increases up to 3 inches before it attaches to the muffler? and therefore i would like the inlet of the muffler to be 3 inch and the left and right outlets to be 3 inch to the corresponding 3 inch tips.

okay so:
"Borla Performance Industries Cat back system (part #140078) installs to the flange located just after the catalytic converter and is made from full aircraft quality high quality austenitic stainless steel. Borla incorporates a single 3” ( good 3 inch!)mandrel bent inlet pipe leading to a 19” long, 10” wide transverse flow muffler(big boom box muffler I like it!). Exiting the muffler are two 2.25” ( smaller than i hope for breathing purposes ) tailpipe tip assemblies. It is a split rear system with a 4” Borla embossed single round, rolled edge, angle cut polished stainless steel tailpipe tip at each exit."

Can i simply purchase just the muffler and two outlet elbow pipe/tips?

 

Racing Beat Rev8 is by far my favorite. It's totally civil. Very deep. But opens up above 4k.
I made my own high flow cat and it got even deeper and slightly louder. (No resonator)
I love it. I'll find a clip. The high pitched rotary sound is inevitable. Its a rotary.

Photobucket doesn't do the best job of uploading videos. This was taken after I modified an OBX test pipe(welded a 3" high flow cat I had laying around)

 

On your diagram, #7 is what most ppl call the "midpipe". Options to replace it include, just a pipe, cat + pipe, cat + resonator, resonator, 2 resonators.

Diagram #3 and #4 together is called a "catback". Every aftermarket catback I'm aware of has a flange between the two for disassembly and shipping. The stock system however has no flange and if the two are taken apart, the FSM warns that it cannot be successfully mated together again.

A good muffler shop can mate anything to anything, so you could keep the stock muffler pipe. It would be unwise however since it's small diameter ~ 62 mm.

2.5" tips are plenty big. Larger ones look cooler, but reduce clearance to the plastic bumper, which, on modded or catless cars, can get the plastic hot enough to burn. Some tips (like the stock ones) are double-walled to control this problem.

 

beware of designing your own exhaust system---you may end up with a dreaded "drone" that can drive you and your passengers nuts.....

 

+1.

I had the exoticspeed S1-T. Everyone loved it, it did sound great but it was LOUD with the OEM cat(midpipe). With the obx midpipe it wasn't streetable. Terrible highway drone.
Would be a great exhaust for FI, weekend car, track car.
Not for me since my car is somewhat a daily, but now I got a beater truck so I can play!

When I made my obx pipe into a high flow cat - I was worried It'd get real raspy and super loud. To my surprise it just complemented the RB exhaust, made it slightly deeper + a touch louder with some popping like in the video.
Here's a pic, shes kinda ugly. I plan on getting it ceramic coated eventually. Cant beat a free high flow cat from left over projects!

 

Price is certainly right. IMO it's worth trying to find a metallic-substrate cat though, especially if one is messing around with tunes or tracking. I've had good luck with a $100 Magnaflow #59959 metallic substrate cat (and a BHR resonator) welded into a $75 used RX7store midpipe. ~20k miles later, no stink, no CEL and a running average of 21 mpg. It probably wouldn't pass a sniffer emissions test though.

For a stock street car, though I have no experience with it, Magnaflow also makes a replacement cat/resonator for ~$300: 2004-2009 Mazda RX-8 Catalytic Converters - Magnaflow 23909 - Magnaflow Catalytic Converters Simple, and rather cheap.

 

True, but most of the ones on the market drone too. Besides, anyone who rides with me is already nuts by definition.

 

I have a greddy SP2 and racing beat dual Resonated mid pipe it sounds almost stock just deeper and more aggressive it gets very sporty sounding around 6000rpms and above sounds great though.

 

Hey I appreciate everyone's continued additions to this thread.

Okay so I'll clear the cat out a bit. Buy a pipe with a larger diameter to run to the muffler. Borla or greddy. Then I want big angle rolled edge tips. Have to find a place to weld those on.
Need to find somewhere to put it on a lift so I can work on the cat and do some of this myself.

 

I absolutely love my Racing Beat catback. Definitely the lowest i've come across and it's louder but really not much over stock. Also i have an AEM intake and surprisingly that does a ton for a deep grumbly sound, but at high rpms that thing whales like an F1 car. Freekin love it! I too am in search of a midpipe to go with everything else that is low and wont make me need to turn my radio up all the way. BHR and RB are my two picks but I don't know how loud the BHR will be in the interior. And the RB has been described as quieter than stock which I'm not a fan of...i want it to be at least a little louder and def deeper. Any input would be appreciated.

 

Make the same one I did. If you don't have access to a welder take it to a shop.
OBX test pipe $100 or so.

Then get one from summit. Metallic substrate like mentioned before.
Flowmaster Universal Catalytic Converters 2230130 - SummitRacing.com
or
MagnaFlow Universal Spun Catalytic Converters 59959 - SummitRacing.com
Even a slightly bigger one.
MagnaFlow Heavy Metal Catalytic Converters 99009HM - SummitRacing.com

So plus an additional maybe $40 to weld up. Your looking at around $250 or less depending on what cat you go with.

Edit - I guess the obx price went up. About $124 but I didn't price shop or look at used stuff.
http://www.erzperformance.com/OBX-Ex...p/obx10112.htm

 

Thanks Charles! The highway drone was my main concern really. I love that it'll get louder if i choose to really get on it. Thats how my AEM intake is and i really enjoy that. Lookin forward to purchasing this weekend!

 

^bhr and rb sound very similar,

if you plan to slam your car i would get the bhr, the smaller resonator will interfere less.

 

Slamming isnt in the near future since I live in Nebraska and it's my daily....I noticed recently you slammed n spaced yours tho and it seemed like you have to deal with snow as well. How well are you getting around?