Please vote / reply only if you're confident in your answer.

I have an Afterburner Vortex exhaust system for classic, inc an 100 cell sports cat.



When advertising it, I'm being asked "Is it 2 & 1/2", or 3" ?"

Pass, all I know is it bolts on the classic turbo car and that you should get it mapped after doing so. My plans changed and ever since I've had it - it has sat in the shed.

So in attempt to find out I took some photos

 

Looks like a 3" downpipe that reduces to 2.25" (std oem size) just before the flange.

 

Thanks mate

 

Agreed, this isn't on your voting choice

 

yesah i'm a little confused as people ask if it's 2.5" but oem wrx is actually 2.25"? So is everyone saying 2.25 when they really should be saying 2.25?

 

Pipework on my UK2000 turbo is definitely 63mm, or 2.5", and I've swapped and changed back-boxes and centre-sections often enough to be sure it's compatible with all variants of turbo-equipped imports.

 

I've never come across a 2.25" system on a turbo. There all 2.5" bore as standard. After market systems eg down pipes can be advertised at 3" bore but then they narrow to 2.5" bore.

As i was looking for a sports cat for my impreza and had to make sure i bought correct down pipe, i needed 3" all the way to connect to a 3" centre pipe.

 

The OD of the OEM centre pipe on my saloon is 2.5/16" giving a bore of 2.1/4".

as per this photo already posted in this thread



same as the Forester before it and the P1 before that.


63mm equates to 2.3/8" which gives a bore of about 2.25" as well.

 

You need a new calculator.
https://www.google.com/search?client...oe=utf-8&gl=uk