Smaller centre box in standard exhaust system

[Matt Scarbro]

Since I bought my car it's been too loud for me, the drone at 50-60 is too much for me, but I didn't know why it was loud.

Turns out the mid-box has been removed which I understand is a fairly common mod.

What I'm thinking of doing is cutting a section of the straight pipe out and replacing with a smaller than standard box.

Bit of an experiment really, as I imagine I'd like it a little louder than standard (never been in a standard car), but can't live with the drone!

From feedback it sounds like an Akrapovic is what I really need but I can't justify that level of spending.

We all like pics so here's a standard exhaust:



I'm guessing that's about a 14" ovalled box.

I'm thinking something like this in place of my mid-box delete pipe:



I need to measure the current pipe but that's the idea anyway...

Any thoughts or ideas?

 

[Christopher]

I have a delete pipe but I only use the car for fun really. I'd look for a flat-bottomed silencer rather than a round, so you don't run into grounding/clearance issues.

 

[Matt Scarbro]

Yeah mine was 'promoted' to daily driver so although I work from home, when I do have to travel it's normally longer trips and the drone gets pretty wearing.

I think most of the ovalled exhausts are 4 or 5" height so no difference to the round ones in terms of clearance.

If anyone has a standard middle box laying around and could measure the dimensions it would be really useful!!

 

[Matt Scarbro]

Thanks to @Dystant we have some standard box measurements...







So it's 14x7x4" as standard.

I'm tempted to try a 14x4x4 stainless box or perhaps a 12" version.

 

[Matt Scarbro]

I got under the car today and measured up...





57.5mm O.D. and it's a little corroded.

Think I'll get away with a slip on 2 1/4" (57mm) I.D. box or will I need to go 2 1/2" (63mm)?

 

[Matt Scarbro]

I have ordered a box in this size:



Will report back once fitted!

 

[Christopher]

Good thinking. I currently have a centre delete and love it, but it'd be good to see a less yobbo option if I ever got tired of it.

 

[Matt Scarbro]

New box arrived his morning, complete with clamps which was a pleasant surprise:



Measured the ID and it was between 57.1 and 57.6mm so I'm hopeful it will slide over my existing pipe with a little persuasion.

I'm away for a few days but will hopefully get it done next week.

 

[luke197]

Hi Matt,

Any updates on this? did you get round to fitting it?

Ta Luke

 

[Matt Scarbro]

Hi Matt,

Any updates on this? did you get round to fitting it?

Ta Luke

Rather a late reply Luke, sorry!

I'm just revisiting this as the first attempt didn't go to plan, there were two diameters of pipe to deal with across that which the previous owner replaced and the original system. Meant it wasn't the quick DIY job I had hoped and didn't want to spend extra money on it at the time.

Current options I'm considering are a complete Scorpion resonated cat back (maybe £400-ish plus fitting), welded in replacement box (£130 quote), or I'm also considering trying one of the Toyosports exhausts from eBay having been so impressed with their manifold...

https://www.ebay.co.uk/i/311928945412

That comes in at £225 and whilst it's not resonated, the 10" stainless box I bought previously has the right inside diameter to allow the Toyo mid pipe to be cut and a section replaced with the box...

Seems a bit ghetto to me, but I'm not sure the Scorpion will be to my taste. If I knew it would be quiet enough I wouldn't hesitate.

 

[Chris]

Rather a late reply Luke, sorry!

I'm just revisiting this as the first attempt didn't go to plan, there were two diameters of pipe to deal with across that which the previous owner replaced and the original system. Meant it wasn't the quick DIY job I had hoped and didn't want to spend extra money on it at the time.

Current options I'm considering are a complete Scorpion resonated cat back (maybe £400-ish plus fitting), welded in replacement box (£130 quote), or I'm also considering trying one of the Toyosports exhausts from eBay having been so impressed with their manifold...

https://www.ebay.co.uk/i/311928945412

That comes in at £225 and whilst it's not resonated, the 10" stainless box I bought previously has the right inside diameter to allow the Toyo mid pipe to be cut and a section replaced with the box...

Seems a bit ghetto to me, but I'm not sure the Scorpion will be to my taste. If I knew it would be quiet enough I wouldn't hesitate.

Ive heard a toyo system in person and they sound really good - loud though!