MPM

Before I share it I don't want to hear everyones opinions on what looks best between a single or dual muffler setup.

I've got a RB header and presilencer. I'm trying to decide on a custom catback or one of the commonly available ones. While drooling at the RB site I thought perhaps a single Turbo muffler would work good with my mildly ported 6-port engine. The muffler(part #16445) is 2.5" straight thru. Thats the same size as my presilencer. A connecting pipe is simple enough. It would be easy to add a small Magnaflow or Borla muffler in the connecting pipe if you need a bit more muffling.

bingoboy

that'd be interesting. i say go for it if you think you'll like it, and then let us know how it performs and sounds.

Madrx7racer

i don't think you'll need any extra muffling......the RB muffler is GOOD. I was also thinking about the same thing.....I have a 3" turbo back onto an N1 style canister(kinda loud) but i really like the RB kit but don't want the weight of both canisters.....keep this thread up to date....i'm interested in your findings.

MPM

I'm not worried about the weight. I do have a budget to deal with. Being married with a child will do that.

I called RB and asked a few questions about the right side turbo muffler. The guy I talked to asked why I only need one muffler so I told him. I was disappointed in what he had to say. He thinks it would be a constriction to have the single muffler. I asked how is a 2.5" straight thru muffler a constriction on a mildly ported 6-port engine that is daily driven. He simply said that I need to buy the proper catback to be happy. I really think he was just saying that to make a bigger sale commission. I'm still leaning toward the single setup using the RB can. Atleast doing it this way it exits on the proper(right) side of the car.

Madrx7racer

theirs is not straight through though....look.....just buy the right muffler and take it from there.......try to bolt it on and then custom fab(go to a muffler shop) and make a connecting pipe......I can understand the slight restriction because the muffler IS beefy and MUFFLES instead of being straight through like the N1 style canisters but i don't see why he would not approve of it when on their site they sell the mufflers separate for "custom applications." buy it anyways....i don't think a connecting pipe will be more than 20 bux installed.....

bingoboy

not straight through? what are you talking about...its a big roundish can with a hole that runs straight through it. the inlet pipe is bent a few degrees sure, but that has nothing to do with the muffler being straight through or not.

Madrx7racer

RB MUFFLER straight through:



N1 style canister = straight-through:

bingoboy

the pipe is straight through, it simply does not go right through the center of the muffler and have a 900 inch tip on the back end. it crosses the cannister of the muffler diagonally and has slight bends where the piping enters and exits. there aren't baffles or chambers in the flow path of the exhaust in the muffler. if you don't understand how that constitutes straight through, then you can't be helped :p

Madrx7racer

so you are telling me that the RB is straight through without any sort of silencing and is the SAME AS THE N1 CANISTERS?

so this(which is what I assume The RB MUFFLER TO BE or at least something similar):




EQUALS this:

Mint87RX7

lol

bingoboy

the rb muffler is not what you have pictured. imagine your second picture, with a bigger can, the pipe running from one edge of one side to the opposite edge of the other side, with NO bends inside of the muffler.

edit: what i mean by that is if you cut off the pipes you could look through the RB muffler like that.

and HOLY CRAP the forum is being slow as hell for me right now...

MPM

Below is a quote from the RB site about the muffler I might use. And before you come on a thread and start waving your BS flag I suggest you read a little first and get your facts(or lack there of) straight. I don't appreciate it and nobody else does either.



Muffler 87-91 RX-7
Turbo - Right


Part Number: 16445
Retail Price: $230.00
Qty:







Racing Beat RX-7 Muffler
1986-92 RX-7 TURBO II - Right

This muffler canister is designed to operate primarily with the 87-91 TURBO II, but can be utilized on all 86-92 RX-7s. (We do not recommend the use of this muffler on a non-turbo RX-7 due to the noise level.)

With over 20 years of exhaust system production experience, Racing Beat has the ability to match the correct internal muffler canister design to the engine’s exhaust output to provide the optimum combination of sound and performance. What does this mean to you? You are assured of a high performance exhaust system that has been designed and "tuned" particularly for the RX-7!

This muffler canister is manufactured using 304- stainless steel and features a 2.5-inch diameter straight-through design for maximum performance gains. Finished with a 3-inch polished 304 stainless steel tip, this muffler sounds as good as it looks! This bolt-on component comes complete with a mounting gasket, and can be ordered separately or with the Left Muffler (Part No. 16446). This muffler will bolt directly to the stock Y-pipe or the Racing Beat Y-pipe.

RexRyder

iTrader: (10)

i love my straight throughs, i can hear the rotors combust as a crank it over. its a great sound. I have 3" duals tho. (3.15" dp, 3" mp, 3" Y-pipe!!!!) none of that narrowing down to 2.5" y pipe bull ****. 3" all the way.

Tofuball

A friend of mine ran a hose through an RB muffler to answer that, his answer:

It's streight through.

NZConvertible

RB's systems are good in part because they use two mufflers in parallel. It would be foolish to think one straight-through muffler would work nearly as well.

As yes they are straught-through, even though the inlet and outlet are offset. That's completely different to the back-and-forth muffler you posted a pic of.

It is basically the same, the RB cannister is just a lot bigger and hence has a lot more sound absorbing material.

Don't assume unless you have specific knowledge to back up your assumption. If you don't know, don't post.

Tofuball

I'm convinced Mazda decided to go with a dual exhaust on the FC because it is a very loud engine, and needs the extra muffling of the two mufflers. (And it looks cool)

(WARNING: PERSONAL OPINION): I've heard many, many different exhausts on the RX-7s that come through the garage here, and the dual systems always sounded better (Quieter, smoother, better tone) then the singles.

MPM

Thanks for the warning and description Tofuball. Working in a shop you have a unique opportunity to listen to many setups. I appreciate it.

Madrx7racer

I have been i retract all my statements. I apologize for my mistake.

MPM

Whatever.

RexRyder

iTrader: (10)

who cares.

Tofuball

No problem. I should also add that the dual setups tend to 'fart' a lot less :p

(I highly reccomend trying to meet up with a few RX-7 owners in your area so you can listen to the exhaust note and decide on one you like)

MPM

I don't have a problem with farting. My wife does Both with the sounds I make as well as the car. Now that I think about we both smell bad if not using a catalytic convertor.

Sadly there aren't to many RX-7's in my area. I'll just have to play with my exhaust till I like it and my wife accepts it.

gerbraldy

I had them straight through mufflers on my N/A and they sounded pretty good. I could barely even hear my engine/exhaust with the car idling. They did kinda sound like it was farting when I was decelerating, but I thought it sounded *mean. I'm about to reuse one of them for my 2.5" straight pipe on my 13bt, can't wait to hear what it sounds like (loud farts?)

Tofuball

The farting on decell isnt (shoulnt be!) the mufflers, it's usually a fuel problem (check your TPS?)