Testing exhaust back pressure

[quattro-nick]

i have had a audi s4 b6 v8 4.2 in the past and the car have origional 2 exhaust valves behind the last exhaust silencer left and right

[andy10v]

Some E46s have a vacuum activated valve in one tailpipe, there is a also a solenoid in the vac hose to control when the actuator sees vacuum.

[blackS2]

to add some measurements to this... pressure before turbine is on ADC Ch1

turbine is T4 0.96 A/R - 74mm outlet to 89mm downpipe to 76mm exhaust

[diesel des]

So is that 3.98 bar gauge turbine inlet pressure with 2.41 bar boost? What turbo exactly and what power? Would be interesting for you to also measure post turbine e.g. downpipe pressure too.

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[blackS2]

So is that 3.98 bar gauge turbine inlet pressure with 2.41 bar boost? What turbo exactly and what power? Would be interesting for you to also measure post turbine e.g. downpipe pressure too.

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nope, all sensors are absolute. So 2,41 bar boost pressure and 2,98 bar backpressure pre turbine

power level unknown.
Turbo is T04Z

measurement in downpipe would also be interesting, thats right... maybe I do this next

[diesel des]

That's a quite good presure ratio you have then.

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[blackS2]

That's a quite good presure ratio you have then.

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yes... thats my opinion too