Ok, I was thinking about how chambered mufflers would sound on an rx7, like Flowmasters, Edelbrock SDT, etc. I was thinking they might resonate to much I don't know, what due you guys think?

thanks

 

I have heard people say that flowmasters sound aweful on our cars. Never heard a sound bite cause I've never seen anyone run them. Someone might have one though.

 

Apparently Flowmasters incorporate fiberglass in their mufflers, even though they say otherwise. They burn out over time.

 

I used a flowmaster on my IT racecar back in the early '90's, I think it sounded better than most cars. I'll be using one on my new car as well. I don't know if the "40" series fom flowmaster would make a street car quiet enough. And I know there is no f-glass in the 40 series, I don't know about the other quieter ones.

 

huh, can you explane how it sounds? Does it sound like a v8?(with Flowmasters)

thanks

 

they sound throaty, but no where near what a V8 sounds like... i say if ur gunna do it stick with a 40 or 50 series... actually i had a buddy with a NA 89 S5.... and he ran a 80 series and it sounded really nice... but i dont know how loud u wanna go or nething...

 

Flowmaster 40 was good, but LOUD. It was hard to put around town with it, real deep town at idle and opened up strong when you get on it. I'm looking at Magnaflow instead, I suggest the same. They use SS and some other matting in the chamber area. Look carefully though, as some of them are straight-throuh design as well.

 

Its hard to describe the sound, I think it sounds like the old GTU cars from the '80's but to some here, they might not have been born yet to hear those cars on the highbanks of Daytona. Less like a chainsaw or dirtbike, more like a chainsaw with a vance & hines pipe off of a big crotch rocket. Does that give you any idea?

 

well, I can kind of imagine how it would sound. To bad there aren't any sound clips.

 

Do not use a chambered muffler. They flow like crap, imo sound like crap, are not as durable as steel-packed mufflers and cost almost as much. Get a straight throw muffler, and if you want to make the exhaust quieter, either add another muffler or use an offset inlet or outlet to reduce noise further. Magnaflows sound great on rotary powered cars, and there are a few Dynomax mufflers that are acceptable. Those two are quality budget choices, but if you've got the green, Borla XR-1s are one of the more desireable mufflers available.

 

I thought about magnaflows, but I thought they had glass packing in them(which blow out over time). And I was also thinking Borla XR-1s, but I thought that it would be a little over kill for a non-turbo. I don't know.

 

When I get the car going I'll be trying a few different mufflers for sound level and power. We have to be under 103db racing so that is not a street issue(way to loud for the street). As for flow, I use a magnehelic to see how much, if any, backpressure is created by any muffler. The best flow I've found is a muffler that I made and that we are using on one of the racecars, its a straight through, perferated pipe with lava rock. Just a cheap(about $40) version of the mazdacomp stainless one. It's just not quiet enough racing,106db, so we are adding a small borla ahead of it under the seat area. It shows almost no backpressure, maybe 1-2" of water on the guage. The worst one I've tested so far is a spintech, it buried the 15" guage at about 5500rpm. It was quiet though, about 93db.
I'll see about making some sound clips.

 

Magnaflows are stainless steel packed mufflers. They'll last long and make a deep sound. Are you going to be making just a catback? If so you'd probably be fine with just one magnaflow 6" muffler on both sides.

 

Well, the previse owner had some cheap catalytic converter and mufflers put on. Now they are rusting and blowing out, so they need to be replaced. When they put the stuff on they did a tarable job welding and bending the tubing. The exhaust on it is junk, I'd say I'm losing 15 horsepower(if not more)over stock.

So to anser your question, I will be redoing the entire exhaust.

 

Flow through a muffler is all relative. Just because a chambered muffler may or may not flow better than another type of muffler does not necessarily mean that it doesn't flow the requirements of the engine. Most people forget that and only think of max flow potential. The engine can only flow so much air. After you have a muffler than can meet these requirements, anything additional isn't helping you.

There is no packing inside a Flowmaster at all. They only use a chambered design. Each series has a different type of chamber design and a different number of baffles. Flowmaster does not recommend their own mufflers to be used on rotary engines. The resonances of a rotary exhaust can weaken the welds that hold the baffle plates in and they can break apart. It's not saying that it necessarily will but it can.

The flowmasters I heard on rotaries were pretty loud. I personally didn't care for them.

 

I was debating doing something like a traditional V8 style exh. on my 7.
Dual chambered magnaflow or dynomax mufflers with straight pipes exiting right at the bumper (barely seen) with no cat. wasnt sure on sound. Im ready to be almost stock/quiet but with great rumble and sound when in high rpms... not sure what I should redo to achieve that.

 

ive got a big magnaflow single can on my car 2.5" piping back ill take sound/video tomorrow

 

I've got Magnaflows and I agree it's definately a nice deep sound... not ricer-loud, but you certainly know it's running (missing the pre cat though, and have what I think is a high-flow main cat).

 

I had dual 2.5" magnaflow can's on my old t2. Very deep at idle and just right under full throttle. I really like them. I'm scared of this new full 3" corksport for my new T2 looks LOUD. I would really like to hear the 40 series on a rotary though.

 

The whole concept of "max potential" is a misnomer anyway. People ask "How much can this component flow", but there is no single answer to that. The only correct answer would be "How hard can you push or pull the air though it?" The more restrictive a muffler (for example) is, the more work the engine has to do to push exhaust gases through it. That's work that doesn't make it to the wheels to drive the car.

 

yeah i love the sound of my magnaflow. sorry about the delay on the video, i was having trouble getting it off of my camera. I'll upload it after work tonight hopefully

 

do not use a chambered muffler on a rotary. Only use a astraiht through SS. I have owned both a Borla XR-1 0val and a SS magnaflow. Both these will work to change the sound of you rotary. I also recommend you use one of these mufflers inplace of your cats.

Use my picture below to show you were a midpipe/exhaust should be placed.

Also you need to make sure that your exhaust system is not touching the underbody of the car anywhere. If it is you need to make adjustments to the hangars. When the exhaust hits the body of the car it turns the end pipe into a microphone for vibration and its 20x louder than it normally would be.
Thats why you have 2 different 2nd gen owners with the same exhaust setup and one of them is twice as loud as the other and they cannot figure out why. Well now you know.