Measuring exhaust back pressure

[Cracka]

Ok so whats the easiest way to rig something up to measure exhaust back pressure? (pre turbo)

I'm assuming a 1/8th npt steep bung welded on and a foot of bundy tube then just rubber hose to a gauge in cabin temporarily?

Reason being I'm curious what it's doing with the 8cm2 housings on the turbos, and if it warrants moving up to a 12cm housing, being that it is on boost well before it really loads the converter up as it is. There is plenty of room to move up in housing I figure?

[bpm]

That's the way to do it but if it comes on boost that early I reckon you are wasting your time. Put the bigger ones on already!

[Cracka]

Thats my train of thought, but I may as well measure it anyway to get an idea of whats changing. No need to spend money if no problem I figure.

[GSRman]

so you are wishing to check if there is heaps of backpressure when the boost & rpm are up?

[lysdexia]

I reckon the way you've described would pretty much be the way to go, ideally you'd want to use something high temp rated though obviously.

[10sec rx7]

yep thats what you want to do..

[dynoryder]

klampy could of just had the gauge coming straight off the manifold

[crack]

find an old brake line and hose. cut the double flare fitting off the end of the hose and weld it onto the exhaust. reattach the brake line and bend it to suit. cut off after a foot or so. add rubber hose and boost gauge.

if you want to get real tricky then make a spare plug to your Vipec with +5V, sensor signal ground & a spare analogue input. then if you ever need to measure something like exhaust back pressure you can quickly plug in a suitable scaled MAP sensor and go for a drive with it logging against all other engine sensors.

[10sec rx7]

i just use a 100psi pressure sensor on the race car.. works perfectly

[BMWTurbo]

I just used brass compression fittings and 400mm+ of copper tube.

If you are testing, wouldn't hurt to check post turbine either to get an idea of how the exhaust is flowing as this will affect spool also.

[hemiturbo]

Make a restrictive hole also,to lessen the pulsing you will get.

[Datman]

We found in our IPRA restricted turbos, controlling exhaust manifold pressure was key to making more power higher into the rev range. The smaller exhaust housings were choking the engine as the boost & rpm increased.