Manta exhaust Drone

[RevNev]

Manta branded specifically 3inch manta quiet with hurricane headers and cats at this point I’m thinking of maybe fabricating factory mufflers to fit manta.

The front section of the Manta "quiet" exhaust shows a large oval muffler forward of the gearbox crossmember and 2 smaller hotdog type resonators behind the gearbox crossmember. Is yours like that to confirm it's the "quiet" version and you didn't get the "loud" version in error?

 

[HDJ]

The front section of the Manta "quiet" exhaust shows a large oval muffler forward of the gearbox crossmember and 2 smaller hotdog type resonators behind the gearbox crossmember. Is yours like that to confirm it's the "quiet" version and you didn't get the "loud" version in error?

Yep oval muffler followed by h pipe and then hotdogs followed by rear mufflers so yea manta quiet version.
I called the shop ordered from they don’t want a bar of it claiming it was never drone free so kind of disappointed.

 

[HDJ]

Yep oval muffler followed by h pipe and then hotdogs followed by rear mufflers so yea manta quiet version.
I called the shop ordered from they don’t want a bar of it claiming it was never drone free so kind of disappointed.

Manta themselves can’t explain why it’s happening so bit lost at the moment. The original shop also started claiming it’s probably because xforce has better build quality than manta

 

[Not_An_Abba_Fan]

Couple of questions, is it auto or manual? Is it cammed? Do you have an OTR fitted?

 

[I Wish]

Try putting the oem mufflers back on if they will still mate up the the flanges.

 

[RevNev]

Yep oval muffler followed by h pipe and then hotdogs followed by rear mufflers so yea manta quiet version.
I called the shop ordered from they don’t want a bar of it claiming it was never drone free so kind of disappointed.

It needs a couple of "big" rear mufflers like the stock cannister size to stop droning but unfortunately, the aftermarket are too stupid to go "big" at the rear and reduce or increase mid-pipe muffling to control sound level or loudness. They insist on using small rear mufflers and play dumb and confused with a droning complaint, no idea how to optimally configure an effective exhaust system is the problem!

For a loudish drone free 3" rear muffler with a good note, I'd go 8.5" round cannister 14" long centre offset with an open chamber and single 3" outlet, not dual and use oval tips to fill the bumper cavity or exhaust reliefs instead of twin pipes. Dual outlet also increases drone potential if it's not a bimodal setup.

 

[HDJ]

Couple of questions, is it auto or manual? Is it cammed? Do you have an OTR fitted?

Auto not cammed and yes otr fitted

 

[Not_An_Abba_Fan]

Auto not cammed and yes otr fitted

Some OTR's can change the exhaust note horribly. One way I check to see if the OTR affects drone is to pull the air filter out and see if the note changes. Some will, some won't. A lap around the block will tell you if it affects it or not.

And to confirm, the centre section definitely looks like this?

 

[Not_An_Abba_Fan]

Also, check that the exhaust is not resting on the chassis brace. The Manta 3" can sit lower if not fitted correctly and will rest on that brace causing a horrible noise in the car as well. Some places put spacers in, but if you push the rear of the headers up as high as they can go when tightening the bolts, it gives more clearance.

 

[hjtrbo]

As well as everyone else's questions and comments, what is your spare wheel setup? Some just have a plastic infill that came with the tyre goo. That infill panel if you have one is like a wall coupled speaker.