Suggestions please for replacement NA6 muffler

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LiteIsRite
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Suggestions please for replacement NA6 muffler

Postby LiteIsRite » Wed Feb 13, 2019 2:59 pm

Need to replace my stock muffler. This morning the exhaust shop tried a number of types, said they were all too 'raspy', and refitted mine. They are attempting to source an OE one but I'm not holding my breath.

Anyone else been down this path and can offer suggestions for a replacement that sounds near stock?
”How you get there is the worthier part.” - Shepherd Book, Firefly
"Cherry" - Classic Red 1990 NA6 :NA6: [sold]

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hks_kansei
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Re: Suggestions please for replacement NA6 muffler

Postby hks_kansei » Wed Feb 13, 2019 3:11 pm

The only options I can think of are:

Secondhand OEM NA (will all be old though)
New baffled muffler (usually quieter than straight through)
Secondhand NB muffler, with the flange cut off to suit the NA midpipe.
1999 Mazda MX5 - 1989 Honda CT110 (for sale) - 1994 Mazda 626 wagon (GF's)

93_Clubman
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Re: Suggestions please for replacement NA6 muffler

Postby 93_Clubman » Wed Feb 13, 2019 5:05 pm

Try https://www.robblissexhaust.com.au/ or www.cesracing.com.au/ in the Brisbane area as they collaborated with Loch & Gary Stewart in producing their exhaust system.

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LiteIsRite
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Re: Suggestions please for replacement NA6 muffler

Postby LiteIsRite » Wed Feb 13, 2019 6:29 pm

Thanks for the responses so far!

The local exhaust shop have sourced an OE muffler in Sydney, which includes tailpipe and the midpipe forward almost to the cat. $630ish installed (don’t remember exactly, I suffered temporary hearing loss after the $600 bit) which is more than double what I’d budgeted for. To their credit, the shop has not charged me anything for their labour to this point.

Maybe I’ll just put up with the minor annoyance of the buzzing/rattling, but I’m still keen to hear from anyone who has had success with an aftermarket replacement that sounds close to stock.
”How you get there is the worthier part.” - Shepherd Book, Firefly
"Cherry" - Classic Red 1990 NA6 :NA6: [sold]

Mr Morlock
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Re: Suggestions please for replacement NA6 muffler

Postby Mr Morlock » Thu Feb 14, 2019 10:46 pm

Town and Country Geelong is the answer- they have a solution. Brilliant on a NB

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Re: Suggestions please for replacement NA6 muffler

Postby 3gress » Fri Feb 15, 2019 11:00 am

Sorry Gary, I have no advice where the word 'stock' is applied!
I am currently looking for options to reduce my exhaust tone down to a level where hearing loss doesn't become an issue.

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Re: Suggestions please for replacement NA6 muffler

Postby Mr Morlock » Fri Feb 15, 2019 1:11 pm

The T&C system had more volume than stock i.e. it transformed it from nearly no note to a sporty sound but no boom. Buzzing rattling does not make sense to me- perhaps its not fitted properly.

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bruce
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Re: Suggestions please for replacement NA6 muffler

Postby bruce » Fri Feb 15, 2019 2:51 pm

Take it to another exhaust shop.
You would think a proper exhaust place would have a stock of mufflers which could easily be modded to do the job.

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LiteIsRite
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Re: Suggestions please for replacement NA6 muffler

Postby LiteIsRite » Fri Feb 15, 2019 5:54 pm

Mr Morlock wrote:Town and Country Geelong is the answer- they have a solution. Brilliant on a NB

Thanks, Mr. M, I've seen T&C recommended here a number of times over the years but had forgotten about them. I gave them a call today and the gentleman there was very helpful - specifying a muffler unit used in systems he builds for NA's. For future reference, it's made / distributed by SWD, and the model is STR7650M - 8" x 4" oval cross-section, 14" long.

I dropped into my local exhaust shop and they ordered one for delivery next week. I'll report back on the result after it's fitted.

Mr Morlock wrote:Buzzing rattling does not make sense to me- perhaps its not fitted properly.

The buzzing I mentioned is inside the OE muffler - something must have come adrift in there, hence the need to replace it.

3gress wrote:Sorry Gary, I have no advice where the word 'stock' is applied!
I am currently looking for options to reduce my exhaust tone down to a level where hearing loss doesn't become an issue.

Somehow, Dan, I'm not too surprised :P I'll bring Cherry around sometime after the fitment for you to have a listen!
”How you get there is the worthier part.” - Shepherd Book, Firefly
"Cherry" - Classic Red 1990 NA6 :NA6: [sold]

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LiteIsRite
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Re: Suggestions please for replacement NA6 muffler

Postby LiteIsRite » Mon Feb 25, 2019 9:27 pm

Reporting back as promised after new muffler being fitted today.

Before...
IMG_0092.JPG

After... (not clear from this angle but it's oval in cross-section)
IMG_0093.JPG

My initial impressions after driving it on a combination of suburban / country / highway roads:

At idle, a little louder. Under load, quite a bit louder - accompanied by a definite growl :mrgreen: Cruising at highway speeds, more noticeable but not intrusive and... no droning. On deceleration, a slightly more emphasised rumble. Overall, a more 'English sportscar' vibe which suits the character of the car IMHO. Both the wife and I are very happy with the result, especially when the cost was lower than originally quoted ($220 vs. $280). For what it's worth, the replacement muffler is probably half the weight of the original as well.

A big shout out to Mr. Morlock for suggesting Town & Country exhausts, who generously supplied me with the manufacturer and model number of a muffler they use in some of the systems they build for MX5s (see earlier post). Thanks also to 3gress for recommending Northern Rivers Brake & Exhaust, who did a great job with the install at a fair price.
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Last edited by LiteIsRite on Mon Feb 25, 2019 9:51 pm, edited 1 time in total.
”How you get there is the worthier part.” - Shepherd Book, Firefly
"Cherry" - Classic Red 1990 NA6 :NA6: [sold]

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hks_kansei
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Re: Suggestions please for replacement NA6 muffler

Postby hks_kansei » Mon Feb 25, 2019 9:38 pm

Interestingly, I suspect your original muffler may not have been the original.
or, if it was, it has been modified.

The oval cross section is normal, however all of the factory mufflers i've seen have had the muffler mounted like your new one, with the wide end horizontal.




Not that it matters now, since it's presumably sitting in a scrap metal bin.
1999 Mazda MX5 - 1989 Honda CT110 (for sale) - 1994 Mazda 626 wagon (GF's)

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LiteIsRite
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Re: Suggestions please for replacement NA6 muffler

Postby LiteIsRite » Mon Feb 25, 2019 9:44 pm

That first photo is also a bit misleading. That muffler is cylindrical, and AFAIK, so is the OE muffler (for reference, see https://www.gomiata.com/gemamioemexm.html)
”How you get there is the worthier part.” - Shepherd Book, Firefly
"Cherry" - Classic Red 1990 NA6 :NA6: [sold]

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hks_kansei
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Re: Suggestions please for replacement NA6 muffler

Postby hks_kansei » Tue Feb 26, 2019 9:48 am

That makes more sense.
must just be the shadows that made it look oval.


Yeah, would have been the factory one then, i remember the NA6 being round now.
I think maybe the NA8 got the oval one? (I know the NBs did)
1999 Mazda MX5 - 1989 Honda CT110 (for sale) - 1994 Mazda 626 wagon (GF's)

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bruce
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Re: Suggestions please for replacement NA6 muffler

Postby bruce » Tue Feb 26, 2019 1:39 pm

LiteIsRite wrote: suggestions for a replacement that sounds near stock?


But you asked for essentially a stock sounding muffler?

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LiteIsRite
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Re: Suggestions please for replacement NA6 muffler

Postby LiteIsRite » Tue Feb 26, 2019 2:17 pm

bruce wrote:But you asked for essentially a stock sounding muffler?

Ahh, bruce, you don't miss a trick :)

Quite right but, from what I could find that actually does that (genuine Mazda), it would have cost me another $400. A bit of flexibility was required!
”How you get there is the worthier part.” - Shepherd Book, Firefly
"Cherry" - Classic Red 1990 NA6 :NA6: [sold]


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