Need to quieten very noisy exhaust

[MK3]

I have a 4 branch manifold and this stainless twin box exhaust on my MK3 Spitfire and to say it's loud is an understatement. It makes an EVO sound like a Prius !

So I am thinking of putting a middle box / resonator ? just in front of the Y and wanted to ask if anyone can recommend a not too expensive box available in UK that will fit in between the chassis rails and will turn this very noisy exhaust into a Sporty noise.

The bore diameter is 45mm / 1 3/4"

thanks

[yorkshire_spam]

I'm in the same position, I'm considering either a clamp in resonator in the straight section OR I hear fitting a GT6 mid-section achieves the same effect.

[WIMPUS]

In my 'wheel barrow' exhaust there is a center silencer also.
Bought the exhaust at rimmers at the time.

I do have a movie somewhere when i drive past slowly so you can hear it a bit ..
But for now here are some pics..

[JohnD]

Those silencer boxes are far too small.

OK, yours is a Spitfire, Silverback was a 2.5, but with boxes twice as long, Sb was just within the race maximum at 96dB.
They were straight-through, with perforated tubes to a fibre-filled cavity.

You could easily accommodate longer boxes, by cutting off some tube after the Y-junction.
John

[GT6 M]

Twin ex, like yours, but with a  4 inch x 3 fut mid silencer = 57DB at 4K revs
as tested at Doune  hill climb, v v quiet,
ev a listen, changed at 5.5 too

https://www.youtube.com/watch?feature=player_detailpage&v=T7XsQymCXy0#t=97

M

[MK3]

796 wrote:

Twin ex, like yours, but with a  4 inch x 3 fut mid silencer = 57DB at 4K revs
as tested at Doune  hill climb, v v quiet,
ev a listen, changed at 5.5 too

https://www.youtube.com/watch?feature=player_detailpage&v=T7XsQymCXy0#t=97

M

That sounds much better, do you have a make / model of the mid box or a link to one being advertised ?

thanks

[GT6 M]

No links to it, I just med it up my self.
if the edges of the chassis tunnel are turned doonwards, then another inch can be gained in width,
and if the tube is squshed slightly  oval, then an even bigger tube can be fitted.
quite simples really

A bigg middle box really does quiet,n it doon alott. put an expansion chamber in the first 8 inch or so too, then rest is straight thru baffled ex pipe.
Happy Tinkerating.

here a few pics in situ

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also helps if ye re pack the back boxes too







sealed up , a few taks, then siliconed around, never leaked at all in alonnng time noo





M

[thescrapman]

Your systems are noisy as that manufacturer is always very noisy. I have never known a quiet Bell system.

You could try swapping to a different make (I have a Phoenix one, much quieter)

The anti-resonance boxes are renowned for rattling between the rails, so need very careful alignment.