How to measure exhaust backpressure?

[Hugo]

I'm going to construct a new exhaust, but I want to measure it's improvement. Can I measure pressure at the O2 bung 'before and after' exchanging the exhaust? What type of pressures should I get (what meter to use)?

Thanks,

Hugo

[Michel.]

Remove your O2 sensor, or install a 'T' and route a long, heat resistant hose attached to a pressure gauge, and tape it to the windshied.
I cannot tell you the range of pressure for a Bimmer, but it's the way of doing it.

[Jami]

Hi!
I have two gauges at the collector before turbo (both sides, splitted turbinehousing). At 2 bar boost i'm reading about 1.5 to 1.6 bar exh. pressure. Next I'm interested how much the rest of the exh. tubing adds pressure to the whole system. If I have more boost on the intake side than the exhaust then there is some point afterall:) Int.p. must allways be above exh.p.! So I must add measuring points to the exh.pipe. to get the idea of the total resistance of the system.
I have used normal (cheap) oilp.gauges. Braketube is good to conduct the pressure. About 1 to 1.5 meters and on spiral cools exh. gases down, then I have tubing that came with the gauges (which is too hard - going to silicone hoses in future).
HTH Jami