Exhaust System Bore Diameters.........

[GalleyZS]

Simple question can anyone provide a list of the exhaust system diameters for all zs engine configurations.

Had no luck on MGR.org hoping i will have more here.

[talkingcars]

Hi and welcome to the forum.

Sorry, I'm as much help as .org.

James

[grimmy]

If I get time.later today I will.measure up my spare mid section that I have in my garage for the 180.at least that would be one of the sizes for you .

[Mark S]

exhausts are measured od.

zs180 is 2.25" stock

scorpion 2" 180
janspeed 2.25" 180
piper 2.5" 180

The 120 I had for a short time looked 2" or even less, but it had replacement exhaust parts which may have been a different bore, but in was minute!

[stamford]

Pretty sure the 120 had the same cat-back system as the 180 in OE guise.

[dave23572]

I can also tell you that the exit of the Janspeed exhaust manifold is 2.25".

Presumably therefore, there would be no performance advantage going bigger than this from the manifold back?

[GalleyZS]

Thanks for the replies.

I'm looking to remove my 120's centre box from the exhaust so wanted the diameters because I'm potentially braking a 25 mk2 and was going to use a section from the centre pipe off that to weld in instead of the centre box.

[p_b82]

the derv's start at 2.5 (although squashed) and narrow to 2.25 along the length from downpipe to backbox. not that it helps as your's is petrol, and all the clamps are different across them!