Thread: Cat delete.

Originally Posted by Tins

Is there really enough good stuff in a D2 cat to cover the postage across the country, James?

Probably not, but I thought it was worth a laugh!

I bought a new flex joint for my 99 after reading that it was a restriction on the early ones.

After pulling the pipe and measuring, I found it was the same size as the rest of the exhaust.

But that's only on a sample size of 1.

Originally Posted by shack

I bought a new flex joint for my 99 after reading that it was a restriction on the early ones.

After pulling the pipe and measuring, I found it was the same size as the rest of the exhaust.

But that's only on a sample size of 1.

I hope thats the case with all of them!

Originally Posted by Slunnie

You could probably just buy a pre-update down pipe pretty cheaply from someone dismantling a Disco2. They never had cats in them.

Potentially the benefit of buying one of those fandangled ones however, is that I understood the factory flex is a choke, and it might address that if its an issue. I've never looked inside mine.

Factory flex was an issue on my 2000. Choke, and failed RWC. Later pipe ( well, one I got from a wreck ) had a different type of flex joint, not the mesh type, more a concertina. Not sure if it presents any issues.

The concertina type is widely used on trucks without issue.

Originally Posted by V8Ian;[URL="tel:3238666"

3238666[/URL]]The concertina type is widely used on trucks without issue.

Yes. It doesn’t need to flex much. I have no idea what the source of mine was originally. But it did have a cat. My original one didn’t.

The O.D. of the pipe is 63mm or close enough to 2.5 inches

The early braid EU2 type had no internal restriction but could flog out.

The later EU3 had the concertina type flex but internally, was restricted down to around 45mm, this helped with velocity, which aided the cat to a degree, as well as losing the distinctive EU2 turbo whistle, but isn't great when getting the engine to breathe.

The flex can be positioned further down if doing the pipe through an exhaust shop or DIY if you want easier access to the spin on filter.

Originally Posted by Slunnie

You could probably just buy a pre-update down pipe pretty cheaply from someone dismantling a Disco2. They never had cats in them.

Potentially the benefit of buying one of those fandangled ones however, is that I understood the factory flex is a choke, and it might address that if its an issue. I've never looked inside mine.

[edit] late to the party again, Craig has already answered it
The bellows type flex is quite undersized internally.
Whether it really affects performance though?