Turbo To Manifold Pressure Drop

[FAST-XR]

I measured my hot side pressure on both tunes (from the actuator line at the turbo)

10 psi tune

Turbo Pressure: 11 psi steady

Manifold Pressure: 9psi and tapered to 7.5 psi

12 psi tune

Turbo Pressure: 14 psi steady

Manifold Pressure: 12psi and tapered to 9.5 psi

So iniatially I have a pressure drop of 2psi then somehow my manifold pressure drops another 2.5 psi while the turbocharger is still pumping out the same pressure...

Does this sound like a boost leak?????

a constant pressure should equal constant pressure drop right?

also is a 2psi drop overall acceptable? (that's inclusing hot side pipes, cooler, and cold side pipes)

Edited 17/03/11 09:56 PM by FAST-XR

[PHANTMXR6]

Depends how far into the rev range it starts to taper off.

It may be part of the tune.

Constant pressure at constant revs is correct, but when you cahnge things like engine revs and turbo revs pressures will change.

[FAST-XR]

it tapers off at about 4000 rpm, shortly after hit hits max boost...

[Wenier]

Also pressure is relative to temp and other such things.

[spoolxr6]

What intercooler r you running. A 2psi pressure drop across a crap intercooler is not abnormal.

[Ralph Wiggum]

So is boost drop off up high with a stock actuator with higher than factory boost.

[FAST-XR]

What intercooler r you running. A 2psi pressure drop across a crap intercooler is not abnormal.

a HDI cooler, 580 x 220 x 100...

boost definately seems to start to fade when the motor is hot...

I pressure tested my intercooler piping on the weekend, and found no leaks!

so if my turbo is pushing constant pressure, and I have no leaks in my pipework, im thinking that I might have a leak in the intake manifold somewhere that gets worse after it gets hot...

[spoolxr6]

It's acrross your core. With the HDI intercooler I had a 3-4 psi pressure drop @ about 19psi. We found this after changing over to a Plazmaman core and boost was up.

[FAST-XR]

It's acrross your core. With the HDI intercooler I had a 3-4 psi pressure drop @ about 19psi. We found this after changing over to a Plazmaman core and boost was up.

witht the HDI did your boost curve hold steady? or did it drop off at high revs?

[Epic XR6]

Also another thing to look out for is the blow off valve leaking under boost.

My R32gts-t used to do it bad just swapped it out and it was all good.