Anyone know outlet diam of exhaust manifold to cat

[matth76]

Does anyone know the outlet diameter of the end of the exhaust manifold which connects to the catalytic converters - is it 2.36" same as rest of standard exhaust system or is it slightly less like 2.25"? I'm possibly getting some aftermarket cats or decats and want to ideally get the right inlet diam to match up to the outlet diameter of the exhaust manifold so there's no restriction. I believe the Nismo Y-pipe inlet is 2.5" (which then goes to a 3" outlet) - can anyone confirm? Some decats have different inlet diameters of 2.25" going into a 2.5" outlet. This would be fine for connecting to my Nismo Y-pipe (if indeed it does have a 2.5" inlet). Just wondered what the outlet was of the exhaust manifold - anyone?

 

Thanks for any info.

[ZMANALEX]

Matt,

 

You will not have any restriction from the OEM cast exhaust manifold to any HFC or test pipe that you may choose to fit.

 

The ID of the cast manifold is 2.15" (54.62mm) but it is resonated so the true ID is only 1.57" (40mm)

 

Alex.

[matth76]

Cheers Alex.