Helmholtz exhaust combination for NC Miata

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Helmholtz exhaust combination for NC Miata

Postby PhillymanH661 » Sun Nov 22, 2020 10:24 am

Morning fellas and gals! I'm reposting this question here from miat.net. I'm going to be in the market real soon for a new midpipe and muffler. The helmholtz midpipe is a no brainer, however I've been bouncing around between mufflers. My current pick is the helmholtz race single. The thought of both portions of the exhaust working to eliminate drone while having some decent decibels and exhaust sounds is very enticing. But would pairing these two together (with a catted header) cause the exhaust to noticeably lack bass? I ask only as I've read somewhere that the helmholtz does remove SOME bass, and was curious if that effect would be compounded in a bad way by having two in one system. For reference, I currently have the gwr catted header with stock mid, and a muffler delete (which sounds surprisingly good). Anyone have a sound clip or review they could share? I can't find that particular setup anywhere.
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Re: Helmholtz exhaust combination for NC Miata

Postby Brian » Mon Nov 23, 2020 9:04 pm

Both Helmholtz chambers working together does work to kill more drone. But with non-stock header the result will also be pretty loud overall. Our usual suggestion with any header change is helmholtz midpipe and our most substantial muffler at the back to knock down some volume and take care of rasp...which is SuperQ.
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Re: Helmholtz exhaust combination for NC Miata

Postby PhillymanH661 » Tue Nov 24, 2020 4:41 pm

Brian wrote:Both Helmholtz chambers working together does work to kill more drone. But with non-stock header the result will also be pretty loud overall. Our usual suggestion with any header change is helmholtz midpipe and our most substantial muffler at the back to knock down some volume and take care of rasp...which is SuperQ.


Sound will never be an issue for me over here in TX unless I'm straight piped. Rasp however is something I definitely don't want on a 4 cyl :(. Not that I can't take your word for it, but it's something I'll have to hear for myself which can only mean one thing... Guinea Pig :D! Of course I'll post videos for anyone who'll have the same question, assuming my mind doesn't change by the time i have the means. Do you think the baffle insert would help in regards to rasp?
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Re: Helmholtz exhaust combination for NC Miata

Postby Brian » Tue Nov 24, 2020 5:22 pm

Tossing baffle at rasp is like spitting on your camp fire, not much accomplished. Baffles knock down a few db, that is all, killing rasp really needs some significant muffler size with significant amount of fiberglass, which is why the SuperQ is as big as it is.
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Re: Helmholtz exhaust combination for NC Miata

Postby PhillymanH661 » Tue Nov 24, 2020 7:21 pm

Brian wrote:Tossing baffle at rasp is like spitting on your camp fire, not much accomplished. Baffles knock down a few db, that is all, killing rasp really needs some significant muffler size with significant amount of fiberglass, which is why the SuperQ is as big as it is.


Duly noted! Just so we're clear here, would you consider this rasp? This fellow has a max power header, gwr catted midpipe, and helmholtz race muffler. I'm trying to imagine that this would be close to my setup soundwise. Or I could be way off base :? https://youtu.be/QtDKbEJsWcA
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Re: Helmholtz exhaust combination for NC Miata

Postby PhillymanH661 » Sat Dec 05, 2020 12:50 am

Just posting this here for anyone that may be watching this thread. Here's the link to the full thread at forum.miata.net: https://forum.miata.net/vb/showthread.php?t=729588

Quote:
Originally Posted by Streets Ahead View Post
Tried it yet? I'm interested in the results.

Results will not be had until about maybe a month from now. This coming Friday, I'll be buying the midpipe off of a member. Probably about a month later I'll be getting the muffler. Things have been happening faster than I've expected so hopefully that's the case here as well . Otherwise, in my desperate attempt to try and get an idea what this would sound like, I've found two clips.

https://www.youtube.com/watch?v=QtDKbEJsWcA
This one has 1.8 max power header, catted midpipe, and helmholtz race muffler

https://www.youtube.com/watch?v=jbdU...ubarKevinBubar
And in this clip the car is running gwr street header, helmholtz mid, and race muffler.

I'm curious how much the helmholtz chamber will change the sound from the 2nd as it's basically the setup I'm going for but with two chambers.

There's also this clip: https://www.youtube.com/watch?v=58VGHslEQeQ&t=366s in which no offense to the owner, I'm hoping is not the sound I get. He's running similar to clip #2, however his header is not catted.

Edit* According to comments for clip #3, sound is not being picked up properly on video. Apparently doesn't sound as raspy as what's being heard, at least from outside the car.
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Re: Helmholtz exhaust combination for NC Miata

Postby DanielS005 » Thu Mar 11, 2021 1:30 pm

Hi All,

I just received my Helmholtz mid-pipe combination package and wanted to give a little feedback. It's a shame that this box of jewelry will never be seen. Everything was received on time and the packaging was incredible. I hate to say...almost to a fault. My box arrived totally packed with packing pillows and the mounding hardware was wrapped in one of the Sealed Air bags with only about 15% visibility. If the bag didn't feel heaver than the rest and in all the excitement it could have easily gotten tossed out with the box. Just a heads up for Brian to either include a big red note to look for the hardware or maybe pack the hardware in clear bubble wrap.

Keep up the outstanding world-class products and service.
Regards,
Dan
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