Jabberwock

Hey, how's it going guys?

I have been planning and debating about going with a custom catback exhaust system. I wanted some of your opinions on design, sound, and quality.

I was planning on going dual Spintech mufflers with 3" piping all the way, but then I thought a single Spintech muffler might be efficient enough. From what I understand and have heard, Spintech exhausts flow really well and are considerably quiet. My idea with a single Spintech muffler would probably have a Y-pipe to go dual piping for Dual tips. The tips will be resonated.

I was also thinking of going with a Spintech Split Case Sportmans Muffler, which has a Single inlet and a Dual Outlet, so I don't need the Y-pipe and can go with Dual Resonated Tips, also.

I was wondering if you guys think that a single Spintech Muffler with dual resonated tips would be unbearable, bearable, or pretty quiet. Also, I already have a Resonator installed on my HF cat to quiet things down.

Another muffler option I was thinking about was the Aero-Turbine Muffler, but I don't know if it is reliable or just a waste of money. The conept is pretty interesting, but I don't really believe the benefits. It supposedly speeds up exhaust flow, which will keep the exhaust cooler, increase *gasp* Fuel Mileage, and increase HP.
Here is a link to the Aeroturbine muffler:
http://www.aero-turbine.com/buy/details_3030.html

I was also wondering if anyone had experience with Moroso Spin Flow mufflers and Dynomax Bullet Mufflers and if any of these would be good for the RX8.

Let me know if you guys think this a bad idea or good idea.

Thanks

dtorre

thats a truck muffler......

TeamRX8

iTrader: (25)

Spintech is a very heavy muffler ... but at least it doesn't have internal packing to burn up like the others

Jabberwock

That was the only one thats 3" inlet and outlet. Its only truck because they think only truck uses those diameters. They have one that says CAR and Truck that is 2.5."

The spintech muffler I want is 8lbs, so if I go single its not too bad, but if I go dual mufflers I already gain 16lbs. TeamRX8, what do you think about the loudness if I go single Spintech, since you had experience with a burns single muffler.

I know the dynomax bullet is really light, but I have no idea how loud it would be to go dual Dynomax bullet. Anyone have any experience with it?

TeamRX8

iTrader: (25)

Bullet will be loud, Burns was loud but intended for race only, somebody here did a Spintech before, it's dog face ugly but seemed to work OK, I think it's in the sticked exhaust thread at the top of the forum, 3" will be on the loud side regardless of what you use

here it is, he did dual mufflers:

http://www.bobclevenger.com/RX-8/index.html

rotarygod

I heard that exhaust system a year and a half ago at Sevenstock. That was probably the nicest sounding RX-8 that I have heard in my opinion. I loved it. No it wasn't the best looking exhaust but last time I checked looks didn't really affect power or sound in any way. If it were mine, I would have powder coated the whole thing black and used chrome tips but that's just me. There are ways to make it look nice.

The aeroturbine mufflers are a waste of time. They are a gimmick and they don't muffle for crap. I've seen their website and seen their claims as to how they work and let's just say air and sound don't work the way they claim they do.

Jabberwock

Thanks rotarygod, I figured the aeroturbine was just a gimmick.

I already researched the spintech here TeamRX8, that was the reason I wanted to go with the Spintech, but thanks. Also, I think that 3" would be loud regardless; however, Spintech had a muffler on a racing application and it was actually noticeably quieter than 95db.

I'm not really into how a muffler looks anyways.


Rotarygod, did you think the Spintech exhaust on the RX8 was loud? Louder or Quieter compared to stock? Do you have any idea on how loud it would be with a single muffler and resonated tips?

Jabberwock

Anyone have any experience with the Moroso Spin Flow muffler? It looks like a prettu good desigin.

rotarygod

I didn't think it was loud at all but then again everyone has their own interpretation of what loud is. It wasn't as loud as th Greddy system or a few others out there. It also was not rapsy at all which is what I really liked about it.

I don't know which actual mufflers he had. That may be something he posted in some old thread somewhere. That'll make a difference. A sinlge muffler will nearly always be louder all things being equal. 2 mufflers is twice the muffling ability (logically!). It actually doesn't quite work that way with them in parallel to each other but you can see there is more muffling ability. 2 mufflers with smaller inlets and outlets will also allow less sound to pass through them than if the inlets and outlets were larger. There are many things that could make a sinlge muffler quiter than duals and vice versa but for the same muffler designs, 2 will be quiter than 1.

I'm going to go out on a limb and say that only 1 Spintech muffler will be pretty loud. If you used a midpipe it would probably be unusably loud.

I've heard mixed results about the Spinflow muffler. If you know how air flows in relation to direction you can almost reach the conclusion that their design will not do what it claims it will either. They are trying to get the air to spin. The problem isn't so much that spinning air is a bad thing as it isn't but the way in which they spin it. In order to spin it like they are (or the tornado intake), you need to change the direction of the air. It doesn't appear this way but you are. Spinning the air is useful in some cases but exhaust flow isn't neccesarily where it's at. Just changing the direction of the air also isn't neccessarily going to quiet it. The Spintech spins the air in a different direction than any other methods. This is why it actually works.

Imagine air flowing through a pipe that bends. Don't worry about any spin. If you have a pipe that does a 360 bend on it's way out, isn't this spinning the air? It all depends on your dimensional frame of reference. This is what the Spintech muffler does. It spins the air inside little metal guides inside that move air tangentially. The Spinflow and other vortex generators rotate the air on a different axis. That involves physically changing the direction of the air inside the pipe. Now you are getting it to flow 2 directions at one in the same pipe. You are trying to make it flow down and around the perimeter of the pipe. If there is more flow on the outside of the pipe and less at the center, that must mean the air on the outside is compressed into a smaller area. You can't tell me what won't be seen in some form or fashion as backpressure. It's not about spinning the air. It's about flowing it efficiently.

Just to deal with the Tornado intake device since I mentioned it (and like typing alot!)I know the demo for the Tornado intake device uses a couple of 3 liter bottles put together end to end and then watch water flow from one bottle to the other and then spin it to see it flow faster. If you don't know what's really going on, this may look like a convincing display. The creator even claims to be an engineer! However we are not only seeing air flow into the bottom bottle. We are seeing the air it displaces trying to get back into the top bottle. The spinning vortex creates a hollow path in the middle that allows the air to flow upwards. This lack of resistance lets it flow faster with the vortex. Place a tube from the top side of one bottle to the top side of the other bottle connecting the air supply on both bottles and it will flow just as fast as the spinning water but without the spin. That's the displacement of air going through the tube and the water going the normal path. An intake an exhaust system don't do this. We don't have completely sealed off systems. Any spin will be lost in an plenum chambers or collective junctions anyways. We have flow in one direction not 2. Ignoring acoustics and the spring effects of pulses. For all intents and purposes we aren't trying to displace one thing for another. We are just moving air. We don't need a vortex to do this. The vortex in this case will only hurt airflow by slowing it down.

Keep the design simple. You only need so much flow. Anything more does nothing. Just to keep your brain thinking a little bit, mufflers that are straight through have the same effect on an exhaust system as just lengthening it with more pipe. Chambered mufflers such as the Spintech essentially appear invisible to total exhaust length as long as it has the appropriate flow levels. Even good flowing straight through systems that don't hurt flow still have a tuning difference on a system. That should get some people wondering about exhaust design and muffler use!

Jabberwock

Ok, thanks rotarygod. Well I was hoping the cross flow spintech muffler with dual outlets may quiet the exhaust a lot, but there is nothing really I can base that on.

DARKMAZ8

doesn't magnaflow offer 3" inlet/outlet mufflers?

Jabberwock

Yes magnaflow does, but I think they are pretty loud, expensive, and loud. I really want the Spintech mufflers for the deep throaty rumble it makes.

TeamRX8

iTrader: (25)

G. I. G. O.

TiLm

well i just put a single HKS high flow and SR high flow cat here are some pics. i love the sound but it is louder than i wanted. So anyhow like or not here are the pics.

ddub

Single fart can + rotary = LOUD.




I also have a feeling your bumper is gonna get melted to ****

TiLm

no i made a heat shield and painted it wit high temp paint so it wouldnt melt. you cant really see it unless ur close

Jabberwock

Heh...I don't really consider Spintech Mufflers fart cans.

I think the split case cross flow design may be pretty quiet, but if it is not I may go with a small resonator.