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How to tone down sound

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Old 02-02-07, 09:51 PM
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How to tone down sound

Hi guys i need to find a good muffler to buy the will quite out the sound some so that i can start street driving the 7. Right now the car is rocking a 12a with a half bridge, RE road race header, and weber downdraft. The current system doesn't quite the car at all because of the apc glass pack with a 4.5" tip. The car is having a 13B 44mm p-port installed later this year and will also be street drivin.

I would like to get something that sounds good at idle and under a heavy foot as well. I'm going to replace the stock 12a pipe with 2.5" stainless steel. Should i use a presilencer as well. Now i dont want to blow the back on the muffler since the parts alone for a highrev p-port are killing me, but i have all i need for it now.
Old 02-02-07, 10:31 PM
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The presilencer is what will quiet the system down. Then if you have money left over put a racing beat muffler on. The best thing you could do for it performance wise and sound wise it the RB streetport system.
Old 02-02-07, 10:39 PM
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I run the Racing beat SP system and i love it, it's not too loud only when your W.O.T and it performs well. Pricey but worth it.
Old 02-02-07, 11:04 PM
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On my old big streetport 12A, I ran a custom Rotary Performance "header", 2" primaries, into a 2.5" collector, 2.5" Edelbrock RPM muffler as a pre-silencer to two 2.5" Flowmaster 40 series mufflers stacked side by side. You could talk in a low voice at idle, it sounded like a British sportscar screaming to 8000 RPM and made 115 rwhp with a bone-stock, unported Nikki carb, which was the big air restriction/HP killer.

Old 02-03-07, 09:08 AM
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Originally Posted by 84GSREX
I run the Racing beat SP system and i love it, it's not too loud only when your W.O.T and it performs well. Pricey but worth it.
saves time for fabrication and has all the mouts for your factory stuff !! great parts to buy
Old 02-03-07, 09:28 AM
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Has anyone heard a flowmaster hushpowerII?

http://store.summitracing.com/partde...5&autoview=sku

Is is supposed to be a mellow tone, I have always liked flowmasters, but I have never actually heard one on a rotary, just curious. Is looks like it could be a good fit for a custom exhaust system.
Old 02-03-07, 09:45 AM
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i absolutely love the RB streetport system, but for your proposed setup, i'd have to say my opinion is to go custom. use 2 mufflers, one as a presilencer and one as a main. i've heard good things about Magnaflow, so maybe you should give them a once over.
Old 02-03-07, 12:54 PM
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Flowmasters won't (usually) last on our cars.........Mangaflow owns all!!!!! i love mine!
Old 02-03-07, 12:57 PM
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Yeah, I have a magnaflow on the FC, they seem to be able to handle the extreme hot breath of a rotary, seems to be a good way to roll, and they sound nice
Old 02-03-07, 01:30 PM
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Flowmasters last on rotaries...I've had to use the "lifetime warrranty" on the Edelbrock RPM stainless steel muffler twice, but the Flowmasters are at least 7 years old...I just have to keep repainting the shells..

Right now, the whole exhaust is in my garage. I want to rebend all the pipes with a mandrel bender to replace the frankenstein of a mess that the muffler shop created replacing the "pre-silencer". It's not in use now since my '83 is all stock. Until I pass the final inspection this year, that's all staying on.

Again....Flowmasters have no problem living in the muffler location of a rotary engine.

Old 02-03-07, 07:41 PM
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Quieting a p=port and not killing exhaust flow is a major challenge. You shoud probably run 2-3/4" heavy wall pipe and a Borla for a pre-silencer. There is a trumpet design made for racing rotarys, if you can find one. You may need to run 2 Borlas to bring the db's down, but the more you add the more hp yoou lose.
Old 02-03-07, 10:54 PM
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magnaflow all the way. i say run true duals from the road race header each into a 4 inch round magnaflow presilencer, then collect them into a dual in/dual out magnaflow and weld on whatever tips you like, or leave it without. youll have to stagger the presilencers like rb's streetport system, of course. it would be awesome though.

http://www.magnaflow.com/02product/s...ne=main&id=654

http://www.magnaflow.com/02product/s...ne=main&id=597
of course you could always go with satin finish, too. either way, save a little money over rb, and have something super cool.
Old 02-04-07, 08:55 AM
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i ran a flow master series 40 (i think it was), for a short period of time... it was so loud, it was unbearible!!!! i changed it out to a dynomax race set up and have had it like that for maybe 6 to 7 years now... now it is still loud and my nieborshate me but it isn't like i dd my rx... i like it just like it is!!! they really won't like me once i get my second rx up and running!!!
Old 02-04-07, 12:39 PM
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I run a Flowmaster (not sure which model, 1-2.25" inlet, 2-1.75" outlets) on my 13b 6-port and 2.25" pipe all the way up and it produces good power and tone but is so loud over about 2.5k that any attempts at conversation are absolutely pointless. A presilencer would probably do wonders for it though. Oh and the muffler has been on the car for at least 5 yrs. now and has managed to outlast everything but the header
Old 02-04-07, 01:52 PM
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I originally had the same problem which is why I ran the Edelbrock RPM SS muffler as a pre-silencer. It changed the entire nature of the exhaust note from brap-fart to British sportscar and also allowed conversation again inside the car.

Old 02-04-07, 02:28 PM
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I run 2 presilencers and a magnaflow behind my s/c'd 13b
Old 02-04-07, 04:00 PM
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The silencers work great. I have no muffler and my car is quiet.
Old 02-04-07, 11:14 PM
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I had first used the rb presilencer alon with my magnaflow and it was brutally loud (embarrassing). Then I added a second presilencer, better and finally replace the rb one with an aftermarket one, now it is perfect.
Old 02-04-07, 11:16 PM
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^^^what aftermarket one?!?!? i am about to install an RB header to a mangnaflow rear muffler but i want to add a muffler/presilencer to quiet her down....what did you use?
Old 02-05-07, 12:02 AM
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i too would like to know. everone says presilencer, but from where? if not RB, what brand muffler/presilencer r u using? i too am using RB SP setup on a streetported '74 model 13B and have thought about removing the dual presilencers to see just how loud it gets.
Old 02-05-07, 12:06 AM
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^^+1...i think they are just using a straight flow muffler as a presilencer.....but maybe there are "presilencers" by other companies...i doubt it though....
Old 02-05-07, 09:08 AM
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Edelbrock RPM stainless steel muffler works. The packing is ceramic, will tolerate 1900 degrees Fahrenheit, just make sure you don't let the muffler shop weld anything to the actual shell for mounting. The shape also maintains ground clearance. Think pancake.

Old 02-05-07, 09:45 AM
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Originally Posted by candyassmiler
magnaflow all the way. i say run true duals from the road race header each into a 4 inch round magnaflow presilencer, then collect them into a dual in/dual out magnaflow and weld on whatever tips you like, or leave it without. youll have to stagger the presilencers like rb's streetport system, of course. it would be awesome though.

http://www.magnaflow.com/02product/s...ne=main&id=654

http://www.magnaflow.com/02product/s...ne=main&id=597
of course you could always go with satin finish, too. either way, save a little money over rb, and have something super cool.
I am running the first one magnaflow that you listed back to the stock muffler. It sounds pretty good, but the insulation inside is gone after a few hundred miles. Noise levels are not too bad though.
Old 02-05-07, 09:52 AM
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ive run two different magnaflow rear mufflers (aesthetic reasons), and have had no problems with both. i love them.

this looks cool, but i dont know how it would sound. i always thought this kind of muffler would be a good idea.
http://www.jegs.com/webapp/wcs/store...61477_-1_10265
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