ok i have a 96 6.5 diesel truck i just put the motor in and put a holset35 turbo on and got every thing hook up truck runs great but my waste gate is not working. i have vacuum to the accuator. the accuator seems to be a push style in stead of pull you can blow into the accuator and the rod will go out but you have to use an air compressor to do it. it needs to pull the gate closed right? how does the waste gate work does the vacuum hold it closed and when the engine drops in rpms does the vacuum go away and the exhaust pushes the gate open?

The vacuum holds it closed until the computer detects the right boost level, then it should cut the vacuum and allow the wastegate to bleed off the extra boost.

The engine RPM's aren't so important other than it has to be revve'd up a little to spin the turbo and develop some boost.

Are you getting overboost, or no boost?

it won't build boost by revving it up in the driveway, you need to lug the engine to build boost, you can simulate this by doing a brake stand, but make sure theres nothing in front/back of vehicle that can be hit/run over, and if you are watching the actuator while doing this, stand clear to the side.

other than that, a boost gauge and a steep hill are your friends.

On the factory vacuum setup, it works like qwkphkr says. Since you have the holset on there, I'm guessing you are probably using whatever wastegate actuator came on the turbo. And from the sounds of your description, it uses a common style actuator which is pressure based and not vacuum based. This is completely different from the factory setup. To use this pressure based system, you hook the hose up to the intake manifold. As boost pressure build in the intake, the wastegate actuator will open the wastegate and regulate the boost levels. Using this system, you do no need the vacuum setup unless your engine has an EGR valve.

The only problem could be the boost level that the Holset actuator is set to. There is probably a good chance that it's set to 20psi or more, which is probably more than you will want to run on your truck.

On the factory vacuum setup, it works like qwkphkr says. Since you have the holset on there, I'm guessing you are probably using whatever wastegate actuator came on the turbo. And from the sounds of your description, it uses a common style actuator which is pressure based and not vacuum based. This is completely different from the factory setup. To use this pressure based system, you hook the hose up to the intake manifold. As boost pressure build in the intake, the wastegate actuator will open the wastegate and regulate the boost levels. Using this system, you do no need the vacuum setup unless your engine has an EGR valve.

The only problem could be the boost level that the Holset actuator is set to. There is probably a good chance that it's set to 20psi or more, which is probably more than you will want to run on your truck.

well how would i regulate and adjust the boost. the computer has been remapped and it has the bigger injectors?

would it be better for me to take the factory actuator and customize it to work on the holset turbo or try the actuator that came on the turbo??? im hooking up a boost gauge today to see what kind of boost i have.

You have a couple options. One being that you can try to retrofit the factory vacuum actuator from your old turbo into the Holset, and continue to use the computer controlled system.

If you want to stay away from the vacuum setup, you can buy a new actuator with a lower opening pressure, or get an adjustable actuator. If you get a lower pressure actuator (say 5psi), you can then buy a Manual Boost Controller (MBC), which allows you to manually adjust the low psi actuator to open at a higher psi.

Don.

ok great thanks for your help man

to figure out the wastegates set PR hook up and air compressor with regulator the the wastegate with a gauge slowly increase the air pressure going into the actuator until it begins to open. Then note the pressure reading and that will be the same pressure you will be dumping @

hey guys i seen this "turbo master" on the internet here (the mechanical waste gate controller) is that worth the money does it work because i could buy that and not have to mave my original vacuum steup work...

http://www.heathdiesel.com/images/part/106623_3.jpg

http://www.heathdiesel.com/images/part/100276_3.jpg