Results 1 to 6 of 6

Thread: Wastegate actuator to 6.2 vacuum pump?

  1. #1
    Join Date
    Jul 2020
    Location
    Montana
    Posts
    234

    Default Wastegate actuator to 6.2 vacuum pump?

    The turbo master I bought does not fit the made in China new gm8 turbo that I installed on my Optimizer :-(

    I am trying to figure out if the 6.2 diesel vacuum pump will be enough pressure to make the China actuator work?

    If so, should I run the actuator vacuum line directly off the vacuum pump or between vacuum modular and vacuum regulating valve mounted on the IP? Basically would the transmission regulated vacuum pressure be enough for the vacuum controlled wastegate actuator?

    I do have a good used GM3 turbo I could put on instead of the new Gm8 that has the same bolt pattern as the Turbo Master if this is a better option?

  2. #2
    Join Date
    Apr 2001
    Location
    CA
    Posts
    13,007

    Default

    The vacuum (6.2 or 6.5) pump should provide between 22" and 26" Hg. The 6.5TD electronically modulates the vacuum to the actuator at 15" Hg. Some simple math should show how effective the Chinese wastegate actuator may be at specific vacuum rates. Measure the areas of the wastegates and actuators of both, and compare. Also compare the moment of the wastegate lever. If all are the same or similar, you should expect similar performance.

    You should not use the tranny modulator vacuum valve for wastegate control. It has no relation to the actual level of boost or load. You will need either an electronic or mechanical vacuum control solution, if the vacuum actuator is used. Also consider the operation of the Chinese actuator. Is it NO (Normally Open), or NC, and is the vacuum actuating closure, such as the 6.5, or actuating opening, as in other brands, or is it reversible? If it is a GM-x clone/copy, vacuum should hold the WG closed, while removing vacuum should allow the WG to open with exhaust pressure.

    If you want to use mechanical WG control (Turbo Master), and the controller you have doesn't fit, either adapt it, or fabricate one. It isn't complicated. If the engine is EFI, the electronic WG control is built-in. If you use a mechanical solution, the PCM may have issues with mechanical control if it isn't programmed out. The PCM monitors the WG vacuum modulator (passive), and will miss it if it's not there or if vacuum isn't correct. Of course, if the fuel system is MFI, it is up to you to adjust the system for target boost and EGT levels. Boost and EGT instrumentation is essential once you get away from OEM trim.
    1985 Blazer 6.2
    2001 GMC 2500HD D/A
    dmaxmaverick@thedieselpage.com

  3. #3
    Join Date
    Jul 2020
    Location
    Montana
    Posts
    234

    Default

    Quote Originally Posted by DmaxMaverick View Post
    The vacuum (6.2 or 6.5) pump should provide between 22" and 26" Hg. The 6.5TD electronically modulates the vacuum to the actuator at 15" Hg. Some simple math should show how effective the Chinese wastegate actuator may be at specific vacuum rates. Measure the areas of the wastegates and actuators of both, and compare. Also compare the moment of the wastegate lever. If all are the same or similar, you should expect similar performance.

    You should not use the tranny modulator vacuum valve for wastegate control. It has no relation to the actual level of boost or load. You will need either an electronic or mechanical vacuum control solution, if the vacuum actuator is used. Also consider the operation of the Chinese actuator. Is it NO (Normally Open), or NC, and is the vacuum actuating closure, such as the 6.5, or actuating opening, as in other brands, or is it reversible? If it is a GM-x clone/copy, vacuum should hold the WG closed, while removing vacuum should allow the WG to open with exhaust pressure.

    If you want to use mechanical WG control (Turbo Master), and the controller you have doesn't fit, either adapt it, or fabricate one. It isn't complicated. If the engine is EFI, the electronic WG control is built-in. If you use a mechanical solution, the PCM may have issues with mechanical control if it isn't programmed out. The PCM monitors the WG vacuum modulator (passive), and will miss it if it's not there or if vacuum isn't correct. Of course, if the fuel system is MFI, it is up to you to adjust the system for target boost and EGT levels. Boost and EGT instrumentation is essential once you get away from OEM trim.
    So in other words... you are saying not to hook up the Actuator vacuum line to the line between the Vacuum modulator and vacuum regulating valve? Yes?

    You are saying it is ok to hook the vacuum controlled Actuator directly to the 6.2 vacuum pump? Or fabricate a mechanical wastegate controller since the turbo master does not fit.

    I will try this and get the boost and pyro gauges hooked up and see where the number are.

  4. #4
    Join Date
    Apr 2001
    Location
    CA
    Posts
    13,007

    Default

    Correct. DO NOT connect the actuator to the tranny vacuum valve. It will do nothing to "control" the WG. The same applies to connecting the WG actuator directly to the vacuum pump, which is essentially the same as tying the WG shut. You need a method of controlling the WG according to the specific operating environment and engine parameters, whatever they may be. Try to avoid the "hold my beer and watch this" moments. Tried and true methods will serve you best.
    1985 Blazer 6.2
    2001 GMC 2500HD D/A
    dmaxmaverick@thedieselpage.com

  5. #5
    Join Date
    Jul 2020
    Location
    Montana
    Posts
    234

    Default

    Quote Originally Posted by DmaxMaverick View Post
    Correct. DO NOT connect the actuator to the tranny vacuum valve. It will do nothing to "control" the WG. The same applies to connecting the WG actuator directly to the vacuum pump, which is essentially the same as tying the WG shut. You need a method of controlling the WG according to the specific operating environment and engine parameters, whatever they may be. Try to avoid the "hold my beer and watch this" moments. Tried and true methods will serve you best.
    Well I do not want to fabricate a turbo master since I already have a brand new one... I think my best course of action is to drop in the used GM3 turbo and sell the new made in China turbo.

  6. #6
    Join Date
    Dec 2003
    Location
    Yukon Canada
    Posts
    1,250

    Default

    Yes ditch the chinessium turbo
    It seems the HX35? turbo from the 5.9 cummins is a good choice for the 6.5.
    Maybe look at that as the one for your build
    90 Chev 3500 c/c 4x4,6.2na,400 auto,4:10 gears.DSG Timing gears,main girdle, isspro tach, pyro,boost,oil and trany temp.Dual Tstats, High volume peninsular pump,on shelf, Custom turbo and intercooler 85%complete. Change of plans for the dually, it's going to get a Cummins. Both trucks are Blue 90 4x4 crews

Similar Threads

  1. Turbo Wastegate Vacuum Actuator Bolts
    By campionc in forum 6.5L Turbo Diesel - Tech Support - Troubleshooting - Performance
    Replies: 0
    Last Post: 06-01-2015, 08:02
  2. wastegate actuator
    By maverick_935 in forum 6.5L Turbo Diesel - Tech Support - Troubleshooting - Performance
    Replies: 10
    Last Post: 02-13-2009, 18:05
  3. How does the LB7 wastegate actuator work?
    By markrinker in forum Duramax 6600
    Replies: 15
    Last Post: 02-07-2006, 22:19
  4. wastegate or vacuum pump
    By 82beast in forum 6.5L Turbo Diesel - Tech Support - Troubleshooting - Performance
    Replies: 3
    Last Post: 06-08-2005, 18:40
  5. Sticking Wastegate Actuator
    By DA BIG ONE in forum 6.5L Turbo Diesel - Tech Support - Troubleshooting - Performance
    Replies: 4
    Last Post: 10-24-2004, 14:25

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •