Measuring exhaust housings

[sweetr33]

Something that i have never really been clear on is how exhaust housings are measured and where?

What does 1.06, 1.12 etc mean in exhaust housing size and on trust turbos what is 8cm, 10cm etc mean and where is it measured from? Anyone? Also on the compressor side how is the A/R.60, A/R.70 etc measured and what does it mean>? i just want to get it cleared up, maybe others wonder the same aswell. So anyone?>

[aybee]

all i know is that i have a .61 exhaust housing which is small- hence the rb20. and that 1.06 and 1.12 are big and would be for singles on a rb26, with (im guessing) a bit of lag.

[sweetr33]

i understand the sizes and relative sizes oer capacity etc but am unaware of where there measured from? ANyone?

[DoughBoy]

The radius ® is measured from the center of the turbo (center of shaft) to the center of the cross sectional area (where A is going to be calculated).

'A' can be calculated anywhere on the snail, as it's a constant ratio within the dimensions of the housing - the A/R will be the same no matter what point it is measured at.