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Mufflers for Spec 7

Old 02-28-07, 11:54 PM
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Mufflers for Spec 7

Hello all,

I posted this in the first gen forum without much response. I currrently run a 1984 spec 7 in colorado. I'm allowed by rules to remove the muffler,and cat but need the muffler for sound reasons. I came across a flowmaster muffler for $80 on clearance on the net. First are they any good ie free flow,not too raspy, light weight, and how loud? etc. I don't want to speend a whole lot as it needs rebuilt brakes etc. Thanks for anyone who can help.
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Old 03-06-07, 10:35 PM
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I would suggest using only a borla straight through muffler. i called all the other manufactures and they pretty much told me dont bother with thier product. Borla is the only one that is stainless packed, not glass. So it will last longer than the glass that will burn out in one or two track sessions. I have a borla on mine now and have no noise issues with it and it is good as new. They run 120ish. Mazdacomp sells a lava rock filled one that is rebuildable when the rock burns out but that runs like 700 bucks or something. they suggested borla as well. Also, any chambered muffler will create a hot spot and burn a whole right out the side, and that is from Flowmasters tech dude. he seid they tested theirs on rotories and got that result. Good luck!!!
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Old 03-06-07, 11:53 PM
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Originally Posted by bean13
I would suggest using only a borla straight through muffler. i called all the other manufactures and they pretty much told me dont bother with thier product. Borla is the only one that is stainless packed, not glass. So it will last longer than the glass that will burn out in one or two track sessions. I have a borla on mine now and have no noise issues with it and it is good as new. They run 120ish. Mazdacomp sells a lava rock filled one that is rebuildable when the rock burns out but that runs like 700 bucks or something. they suggested borla as well. Also, any chambered muffler will create a hot spot and burn a whole right out the side, and that is from Flowmasters tech dude. he seid they tested theirs on rotories and got that result. Good luck!!!
By chambered do you mean not straight through? The hot spot thing must only apply to crappy mufflers. I have ROTAFLO mufflers on both of my cars, the older one is 4yrs+ old and is still doing a pretty good job behind a 13bPP. I had a cheap stainless straight through muffler when I had a 13b bridgeport...it lasted about a month of actually doing anything then it might as well not have been there.
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Old 03-07-07, 07:06 AM
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I have ROTAFLO muffler...
Did anyone else read that as "I have a ROTFLMAO muffler..."?

-b
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Old 03-07-07, 07:16 AM
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Originally Posted by wrankin
Did anyone else read that as "I have a ROTFLMAO muffler..."?

-b
maybe you're a bit lysdexic
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Old 03-07-07, 07:59 AM
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I have had very good luck with a Borla on my peripheral port road race car.
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Old 03-07-07, 08:48 AM
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My first respionse to your exhaust question was.

***Goolgle search Spec-7 & you should come up with some info. South Pac Division started the class in IIRC 1994. Being that Spec-7 is a momentum class you can't afford to give anything away through exhaust. You need maximum diameter pipe allowed by rules from the OEM exhaust manifold all the way back with a muffler that just meets the noise requirements.***

My second response to your exhaust question is the following.

Do you have the rules for the Division/Region you race in ? Rules do change by Region/Division. Have you talked to other Spec-7 racers? Most Spec-7 racers are friendly people who will help. There was a Spec-7 site out of Texas.

There is a guy by the name of Paul Gipson out your way that races a Spec-7 & will provide you with the info you are requesting or in need of.

There is a company by the name of Hasport Racing in Phoenix, AZ @ 1-480-517-1161. Father & son Ron & Keith who own the business & they are both road racers. They manufactured & sold the entire exhaust system for Spec-7 cars & it was & maybe still is the syetem to have. If they no longer sell the system they will point you in the correct direction.

This exhaust system for your Spec-7 is not a get an idea from your best buddy because most of the time your best buddy has done zero testing of the exhaust system.

This system IIRC DID NOT use a muffler, it used a specific Catalytic converter & then at a later date the rules changed & the converter could be removed & a test pipe put in it's place. I last raced Spec-7 in year 2004.

Another idea for you would be that you post your same exhaust question on the www.improvedtouring.com site because there are a couple Spec-7 racers that post there.

Have Fun
David
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Old 03-07-07, 03:17 PM
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exhaust

thanks david> In colorado they just allowed you to remove the cat and exhaust system,but noise can't be over 103db. The colorado region also allowed the installation of a racing beat header that gives an increase of 15 hp. At Pueblo last year i think two of the spec 7s had the header. I was told that they'll now keep up with a spec miata,on the straights,not in the corners,
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Old 03-07-07, 05:54 PM
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Spec-7, I can understand that a header with no muffler very well might be over the 103 db level. My ITA 1st gen RX-7 with an ISC racing header, IIRC 3 1/8 O.D. tube over the axle to a Dyna Flow muffler, blue printed carb, cool air intake, big ol cone K & N filter, 4:88 gear in Wisconsin air in Oct. (cool crisp air) will blow 99/101 db.

All I'm trying to say is use the knowledgable people when making decisions on spending YOUR money.

Have Fun
David

EDIT: There is also a SPEC-7 or SRX7 site out in the area of the SouthPac Division. But again be careful because rules change by Region/Division.
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