Shop Installed Wrong Exhaust

[hodgepodge79]

I just got my '87 4runner home from the exhaust shop and measured the pipe they installed. I wanted 2" pipe from the header to the muffler (about 3.5 feet).
I just measured it and it is actually 1.875"-diameter pipe.

Is this enough that I should be concerned about? We are only talking an 1/8" difference in diameter. Any thoughts?

 

[KimoSan]

Smaller exhaust pipe

I wouldn't be too concerned about it as it is a reduction in cross-sectional area of only 12% (based on the outside diameter of the tube only, not accounting for wall thickness of the tube). But then again, I'm not expert on exhaust systems. It's possible that the shop used a smaller diameter tube with a thinner wall and therefore the inside area would still be close to that of a 2" OD tube. If so, the reduction in area would be even less than the 12% noted above.

 

[hodgepodge79]

I was able to get the 1-7/8" ID by measuring the OD (1.99") minus the wall thickness x 2 (1/16 x 2 = 1/8)

Is there such thing as 2" ID exhaust pipe? Or are pipe measurements all made by the OD? example: 2.5" exhaust pipe is 2.5" OD.

 

[Spider5]

I was able to get the 1-7/8" ID by measuring the OD (1.99") minus the wall thickness x 2 (1/16 x 2 = 1/8)

Is there such thing as 2" ID exhaust pipe? Or are pipe measurements all made by the OD? example: 2.5" exhaust pipe is 2.5" OD.

Pipe is measure ID, tube can be measured OD & ID.

 

[KimoSan]

Size of exhaust pipe

hodgepodge79, sounds to me like you got the correct size exhaust if you measured roughly a 2" OD. In my field (aerospace) I deal with tubing all the time and it is always measured as OD x wall thickness (i.e. 2.00" OD x .063" wall thickness).

 

[mikestang]

example: 2.5" exhaust pipe is 2.5" OD.

Correct.