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Hey Guys,

I installed a new exhaust system today, it consists of a set of 4-1 MazdaSpeed Extractors, Maruha 100 Cell High Flow Cat and a Car Make Corns Cat Back System.

Now I am already aware that this is a recipe for LOUD.

After installing it and a short drive... It sounds great. The only gripe I have is that it drones quite a bit between 3-4k rpm. Everywhere else is ok.

My guess at fixing this with out cutting pipe is to reinstall my 300 cell high flow cat and remove the 100 cell. I know this wont change it dramatically, but will it at least take out some drone?

Cheers.

Nope, go to a really high end exhaust shop and have the TIG in a nice stainless hotdog.

It will look like it belongs.

Dann

Thanks Dann,

As mentioned above, I'd rather not modify it as it took a bit to find one in such good nick.

A mate of mine, Johnny has this same cat back fitted to his car with some MaximWorks 4-2-1 headers and a 300 Cell Cat and its not as droney as mine... That's why I asked If that cat would make a difference, as it has more resistance.

Adding restriction to your performance exhaust?

honestly what is the point?

Dann

Haha, I know. Seems pointless, but it's not going to be anything major...

I'm happy to do it if it will make it a little more tame. I don't mind if the difference is not massive, but if it will make the drone a little less "droney", then I'm sold on the idea.

Cheyne, you could try waiting a couple of weeks before you make any changes. Some new exhausts settle down, getting quieter and deeper during the first few drives.

Anyone else have anything to add to this?

It's a used exhaust Manga, imported from Japan...

Consider putting a muffler where the cat goes perhaps?

Dann

CheyneX5 wrote:It's a used exhaust Manga, imported from Japan...

OK, clearly I got confused when you used the word "new" in the first post.
x2 for the hot dog after the cat idea then.

Changing the cat to a higher flow one on my SE system made a big difference in volume, so I would say yes to the reverse.

Yeah it'll change, but it will be a minimal change. You dont hear the droning gone, but it will be less audible. Personal choice would be not to touch it. But it is your car.

Yep - change the cat to the 300 CEL one and most of it will go away. I was surprised how much difference a 100 CEL makes and TBH on a 1.6 it shouldn't really effect performance much at all. It's free to swap it back ;)

Steel cats of that spec are noisy in my experience,much more than ceramic.I agree with the hotdog , say 15 inch but use a perforated one ,have had much better results with sound and quietening using perforated, don't ask why as i don't know.

Getting a good sound and avoiding that drone is the real cahallenge with MX catbacks

Good luck,

Peter

If its affecting sound a lot through restriction alone it must be affecting performance.

Dann