Advice for a quieter exhaust?

[sheeeep]

Hey everyone!

I recently join the club! A NA8! A couple of things needed fixing and replaced (Yellowspeed on the way!) but I'm already a very happy owner indeed

However, the car came with a custom made(I think but not very sure) pipe, and I am finding it little too loud for my personal liking. Almost obnoxiously loud. Plus the exhaust seems to be hitting the rear tow hook when going over bumps.

Using some ultra sophisticated and highly accurate sound meters (aka smartphones and tablets apps haha ) I got about 85-87ish dB revving at 5000rpm 0.5m away from exhaust. I'm wondering how it compares to other 5s out there? Has any of you guys measured your exhaust noise before?

I considered getting an exhaust from mx5parts but hesitated after reading some reviewers suggesting that it's too loud for their taste. I understand that it's very subjective to personal opinion but I fail to find any dB measurement for many exhaust systems being sold online.

Would anyone have any suggestions? Is there anything I could do to my exhaust to make it quieter?

Thanks in advance

[NitroDann]

Thats well well under legal requirements, but the equipment is probably dodgy (tablet and headphones).

grab a photo of it if you can, the answer is almost certainly adding a hotdog if it doesnt have one or replacing the muffler with a larger one.

Dann

[chrisearl88]

Go back to a stock rear muffler?? They can be had for quite cheap, or find somebody that will swap their stock for your custom jobby

[sheeeep]

Thats well well under legal requirements, but the equipment is probably dodgy (tablet and headphones).

grab a photo of it if you can, the answer is almost certainly adding a hotdog if it doesnt have one or replacing the muffler with a larger one.

Dann

Thanks Dann. Just grabbed a pic.

It consist of two pipes, 2.5in each. Too big yea?

[hks_kansei]

85db is almost stock volume, I think the testing equip is out.


My RSR idles at 100db with OK testing equipment (not great, but within 3db either side)

[NitroDann]

Thats not the important bit, can you get anything underneath?

Dann

[Mr Morlock]

just take it to an exhaust shop and it will be done in a blink. All these places will have listings for what mufflers etc are required. If it annoys you fix it for sure. To be sure get a few quotes and perhaps ask around your own area for a recommendation. A stock set up - like the majority of MX5s are fitted with will not be obtrusive.

[sheeeep]

85db is almost stock volume, I think the testing equip is out.


My RSR idles at 100db with OK testing equipment (not great, but within 3db either side)

Yea, I wasn't expecting it to be very accurate. If stock is 85db then my measurements are definitely wayy off.

[sheeeep]

Thats not the important bit, can you get anything underneath?

Dann

Shot from the right side:


Shot from left rear:








Are these shots better? I can't get the mid-section till tomorrow though it's too dark now.

Thank you!

[NitroDann]

Good photos, is there a hotdog underneath behind the cat?

Dann

[NitroDann]

There will be one of these



is there one of these behind it?



Dann

[manga_blue]

It's pretty hard to give advice on an existing set-up over the web but that muffler looks nothing like a stock NA8 one and the general pipework looks rough. Spending any money on that system might be throwing good money after bad.

There's been plenty of debate on this forum about whether or not a good exhaust shop can custom build a better system than you can buy direct. I'd say you should get an assessment and quote from a shop as well as pricing ready made units like the MX5parts.co.uk ones.

Tell us where you live and someone here will point you to the best local workshop for you.

[hks_kansei]

Yea, I wasn't expecting it to be very accurate. If stock is 85db then my measurements are definitely wayy off.

Not sure what stock is, I never tested it.

But 85db isn't particularly loud for an exhaust

[sheeeep]

Go back to a stock rear muffler?? They can be had for quite cheap, or find somebody that will swap their stock for your custom jobby

just take it to an exhaust shop and it will be done in a blink. All these places will have listings for what mufflers etc are required. If it annoys you fix it for sure. To be sure get a few quotes and perhaps ask around your own area for a recommendation. A stock set up - like the majority of MX5s are fitted with will not be obtrusive.

It's pretty hard to give advice on an existing set-up over the web but that muffler looks nothing like a stock NA8 one and the general pipework looks rough. Spending any money on that system might be throwing good money after bad.

There's been plenty of debate on this forum about whether or not a good exhaust shop can custom build a better system than you can buy direct. I'd say you should get an assessment and quote from a shop as well as pricing ready made units like the MX5parts.co.uk ones.

Tell us where you live and someone here will point you to the best local workshop for you.

Instead of going back to stock I was hoping to find something in between.

And, I see what you mean manga. It really feels like a roughly done job.

I'm currently in Gatton, Qld. I know of one exhaust shop in my area but I'm not too familiar with them. Any recommendation for exhaust shops? I'm willing to head out to Toowoomba or Brisbane area.

There will be one of these



is there one of these behind it?



Dann

Following from the exhaust tip forward, the tubular drum as seen in the photos (muffler?) sits right below the trunk. Keep going forward I can see something that resembles your second picture sitting just in front of the rear diff, located about underneath of the arm-rest. I can barely see something similar to your first pic just in front of that hotdog, but not sure, cant get a good view.

The exhaust outlet coming straight out of the engine is similar to what you referred to in your other thread posts, 4 to 2 to 1 and looks to be custom made as well.

And if it makes any difference: KN Typhoon intake pod aimed towards the passenger side mirror corner.

Thanks!

edit: grammar

[NitroDann]

In that case its complete just too loud for your taste,

I would start by cutting the tips off so you have only a single smaller outlet remaining, this will take some of the droney notes out, however My guess is that you will need a bigger muffler to be satisfied with the volume.

Dann