u/Exciting-Ad-2744

Hey all,

Car: 2020 Renault Megane 4, 1.3 TCe turbo, manual, Stage 2 remap (~185hp/300Nm).

Recently had the factory cat removed and replaced with a mandrel-bent straight downpipe (no resonator, high-quality chrome/stainless). All other factory mid and rear mufflers are still stock, untouched.

Since the swap, I'm getting a noticeable resonance — metallic drone/buzz/rattle — from underneath, especially at certain RPMs, loud enough to be felt/heard in the cabin. On top of that, the engine doesn't really "roar" anymore, it more sounds like it's farting/blubbering under load, kind of a raspy, flatulent tone instead of a clean exhaust note.

I'm mainly considering wrapping the downpipe with heat wrap — would that actually help with this kind of drone/resonance, or is heat wrap only useful for thermal management and not sound?

Also open to any other suggestions you guys might have to fix this without swapping the downpipe itself. What would you try?

Thanks!

https://reddit.com/link/1uofj0h/video/fxy9xh8bnhbh1/player

Hey all,

Car: 2020 Renault Megane 4, 1.3 TCe (H5HB/H5Ht engine code) turbo, manual, Stage 2 remap (~185hp/300Nm).

Recently had the factory cat removed and replaced with a mandrel-bent straight downpipe (no resonator, high-quality chrome/stainless). All other factory mid and rear mufflers are still stock, untouched.

Since the swap, I'm getting a noticeable resonance — metallic drone/buzz/rattle — from underneath, especially at certain RPMs, loud enough to be felt/heard in the cabin. On top of that, the engine doesn't really "roar" anymore, it more sounds like it's farting/blubbering under load, kind of a raspy, flatulent tone instead of a clean exhaust note.

I'm mainly considering wrapping the downpipe with heat wrap — would that actually help with this kind of drone/resonance, or is heat wrap only useful for thermal management and not sound?

Also open to any other suggestions you guys might have to fix this without swapping the downpipe itself. What would you try?

Thanks!

https://preview.redd.it/6rvb4rnknhbh1.jpg?width=375&format=pjpg&auto=webp&s=6c452290a41062d9d14cb00a01767e6e267197ea

https://reddit.com/link/1uofhgd/video/vko2br3lnhbh1/player

Hey all,

Car: Renault Megane 4, 1.3 TCe turbo, manual (~185hp/300Nm).

Recently had the factory cat removed and replaced with a mandrel-bent straight downpipe (no resonator, high-quality chrome/stainless). All other factory mid and rear mufflers are still stock, untouched.

Since the swap, I'm getting a noticeable resonance — metallic drone/buzz/rattle — from underneath, especially at certain RPMs, loud enough to be felt/heard in the cabin. On top of that, the engine doesn't really "roar" anymore, it more sounds like it's farting/blubbering under load, kind of a raspy, flatulent tone instead of a clean exhaust note.

I'm mainly considering wrapping the downpipe with heat wrap — would that actually help with this kind of drone/resonance, or is heat wrap only useful for thermal management and not sound?

Also open to any other suggestions you guys might have to fix this without swapping the downpipe itself. What would you try?

Thanks!