[B1ue52]

So my F32 has only done 30k and the middle box/ secondary cat has rotted all the way through right on the seem. It's going in the garage today to either get tig welded or just have the middle box deleted altogether.

The garage that's doing it has a really good rep for building custom exhausts which I am also considering. He's is proposing going straight through from the primary cat back. However, I have a few questions I would appreciate opinions on:

Has anyone gone straight through with no baffles? How loud is it, what sort of noise?

Considering an M Performance rear diffuser and can choose from a single twin exit on one side, split singles on each side, or quad. I need to decide which exhaust style I want to end up with before I order a diffuser and vice versa.

I'd appreciate any opinions.

Cheers

Picture for reference....

[Watsey]

Unfortunately a straight-through exhaust on a 20d is unlikely to sounds much different compared to OEM. I considered it for my 30d but shelved it for the same reason.

Aesthetics is a different matter. Twin exhausts look 'better' to many people, but I'd avoid quads (M car wannabe).

I'd ask to see photos of previous custom work by the garage. I've seen some very neat jobs and also some ugly ones (way to many cuts and rusty welds).

[B1ue52]

Originally Posted by Watsey

Unfortunately a straight-through exhaust on a 20d is unlikely to sounds much different compared to OEM. I considered it for my 30d but shelved it for the same reason.

Aesthetics is a different matter. Twin exhausts look 'better' to many people, but I'd avoid quads (M car wannabe).

I'd ask to see photos of previous custom work by the garage. I've seen some very neat jobs and also some ugly ones (way to many cuts and rusty welds).

Thanks man. I've seen some of his work and it looks to be a good standard to me and he's got a great rep around here.

I was more concerned about it being too loud rather than how much it changed the noise tbh so that belts that fear, thanks

Same opinion on the quads. But you know what it's like, when you have the option to consider all options, well... you have to consider them if only to rule them out

[seenthelight!]

Had the twin pipe conversation done on my 435d as soon as I got it (back box cut out, twin exit pipe welded on, one pipe each side). Looks much better than standard and sounds better too - no louder, just a deeper, fuller sound and slightly raspier when giving it some beans. Had a few folk comment that it is so unlike a diesel, which can only be good. Also fully debadged the rear to complete the look. Sorry no photos, as on phone

[B1ue52]

Originally Posted by seenthelight!

Had the twin pipe conversation done on my 435d as soon as I got it (back box cut out, twin exit pipe welded on, one pipe each side). Looks much better than standard and sounds better too - no louder, just a deeper, fuller sound and slightly raspier when giving it some beans. Had a few folk comment that it is so unlike a diesel, which can only be good. Also fully debadged the rear to complete the look. Sorry no photos, as on phone

Thanks man. Very helpful

[seenthelight!]

Originally Posted by B1ue52

Thanks man. Very helpful

Ok man 😁😜

[Lorcan]

It won't be too loud, probably the opposite, but there is a small risk of introducing some unpleasant whistling noises. Still worth it though I think.

Frankly I think quad pipes on a 420d look ridiculous but ETTO. I prefer one each side, aka "the wheelbarrow".

[B1ue52]

Thanks and yeah, split singles is by far my preferred option.

However, if budget dictates, I may have to consider just a single twin on the left. If that is the case, does anyone know whether if I get a diffuser with the wider opening for a twin, if simply putting a twin tip on a Y pipe will sit in the correct place coming straight out the OEM single pipe box in to a twin width diffuser opening?

Cheers

[seenthelight!]

Originally Posted by B1ue52

Thanks and yeah, split singles is by far my preferred option.

However, if budget dictates, I may have to consider just a single twin on the left. If that is the case, does anyone know whether if I get a diffuser with the wider opening for a twin, if simply putting a twin tip on a Y pipe will sit in the correct place coming straight out the OEM single pipe box in to a twin width diffuser opening?

Cheers

If you require, I have the twin pipe and back box taken from my 435d. It's standard, stainless and V good condition with no marks on the pipes. Would be a straight replacement for the 420d, just needs welding on. Available for a decent price. PM me if interested mate