How do you measure the exhaust size?

[Acecool]

The previous owner put an aftermarket exhaust system on my 240sx, and I was wondering how you measure it?

Do you measure around it (diameter)Top to bottom, or what?

Top to bottom is about 3 inches

[180fan]

get your caliper ruler out and use the side that measures the inside distance of parts. I guess if you were to hold the ruler like if it were a tomahawk, it'd be the small pointed nub of the blade.

OR

get a piece of string and with the pipes disconnected, use the string to get you a ballpark figure of the diameter of the opening, put back together the pipes and measure the distance on the string.

[Acecool]

So basically, go around it with a tape measure?

I have a feeling mine is going to be like 5 or 6 inches then O_O

[LayNLow240]

no, you need to measure the inner diameter. should be somewhere like 2-3 inches. just get a ruler or tape measure and set it on the inside of he exhaust and measure where the bottom of the top is. you dont include the wall thickness.

[Acecool]

Cool, I will swing by my nissan dealer then, and measure the exhaust gasket, since it is a little bit bigger than that.

Thanks

[nightkid86]

Make sure you measure bottom to top.

[nightkid86]

and if it were a 3" exhaust the diameter would be roughly 9.42"

[ZiG]

and if it were a 3" exhaust the diameter would be roughly 9.42"

You mean circumference.

I had to do this when I bought my trans am. What I did was wrap a string around the pipe and pull it tight. Then take a marker and mark the string where it crossed (so mark to mark is one circumference). Then measure the string from mark to mark and divide by 3.14 and you have the OUTSIDE diameter. From there it should be pretty easy to figure out the inside diameter. On my trans am it came out so the outside diameter was like 2.75" so obviously the inside diameter musta been 2.5"

[nightkid86]

Haha yeah, circumference. BTW, are you on gtplanet.net?