2005 STi exhaust diagram?
 

I'm trying to understand what parts I need to purchase.

I have a Blitz Nur Spec R and I wish to decat the downpipe and turn the exhaust into a full 3" system.

I am aware that I need to modify the Blitz as it will taper down to 2.5" but i'm confused about the rest.

I have seen this diagram

https://4.bp.blogspot.com/--0UbAsuF9...st-diagram.gif

I understand the STi only has 1 cat in the downpipe, but how many physical parts must I replace to get what I desire?

Thanks chaps

You just Need a 3" downpipe decat, get your centre exhaust cut and rewelded with a 3" end, I went to a local metal shop on an industrial estate and the bloke done it in 5mins. You will need a 3" gasket for the join, I would suggest buying a new turbo gasket they are cheap enough.

This will remove 2 cats from the exhaust, You need a downpipe with an lamba sensor in the right place.

Thanks, if you look below, which of these would I need?

http://www.haywardandscott.com/subar...pipe-in-3.html

or

http://www.haywardandscott.com/subar...-downpipe.html

The second one is obviously longer but i'm not sure which one i'd require, am I right in saying that the original STi downpipe consists of 2 seperate parts and the second H&S basically combines them?

The STi has two CATs. One in the down pipe and one in the mid pipe.

The PPP style upgrade package removes the second CAT in the midpipe and replaces the CAT in the down pipe with a Sports CAT. So goes from two CATs to one Sports CAT.

The second pipe you show above combines the downpipe and mid pipe in to one full decat pipe.

If I remember rightly, the NUR Spec R is a CAT-back system so replaces the rear muffler and the rear exhaust pipe (including the resonater).

So if you want a full decat system you would need the longer pipe.

By the way, that is gonna be LOUD!!! :eek2: Hope you don't mind upsetting your neighbours! :lol1:

Thanks for your explaination mate, yes it's gonna be mental loud!

I have what your getting ( already fitted when I bought it ) and it sets off car and van alarms as I pass. I've also been told I can be heard from over a mile away coming home from work :D