Boost Sourcing a Wastegate?

[Y-TRY]

What is the best way to source the ports on an External Wastegate?

Many diagrams I've seen use a line from the compressor housing to the side port of the wastegate. Other set-ups are sourcing the same wastegate port directly to the intake.

The top port of the wastegate is after the boost controller, which is also either sourced at the manifold, or at the compressor.

I recently saw an HKS digram that specified NOT to use the manifold for a boost source, but I see cars like Monty's Corvette successfully reference to the manifold.

I've also 'heard-tell' that only one or the other (top or side) port should be used on the wastegate, but not both. And also that the wastegates can be referenced at any point that sees pressure during boost. If that's the case, they could be referenced anywhere in the intake system.

As I understand it now, the side port introduces pressure under the wastegate diaphragm. With enough boost present, this will overcome the internal spring and lift the valve off its seat- bypassing the exhaust gasses from the turbine. Right? So it would make sense to reference this to actual manifold pressure. However, manifold pressure will introduce vacuum into the wastegate during driving, while non of the other sources would.

Can anyone clear this up for me, with some references? I am having an issue with my wastegates and I want to be able to rule out, or re-consider, how they are plumbed.

[pushrod243]

Try asking on these two forums if you dont get much response here.

http://turborides.com/

or

http://www.turbobuick.com/forums/

[nitrorocket]

Go of the turbo port. They will react faster and be more accurate. It does not matter if the boost level at the turbo is different then the intake( due to intercooler pressure loss). You will be setting the boost controller to the intake pressure. This way it is harder to overboost.

[hotwheels]

It has been my experience with turbo's that if you are running a manual boost controller, you will be better off using the side port's on the wastegate. Your reference point really doesn't matter.....I chose to use the one on the side of my driver's side turbo...........work's great......but, you can source off of the manifold if you have a spot where you can hook up a line.....