TheDieselPage.com Forums  
2014 - TDP's 19th Year
What's New: | Feature Articles: | Product Reviews: | Member's Area: | Subscribe:
Duramax 6600 Diesel Page | Advertiser's Section | Classified Ads | Photo Album | Diesel Books, GM Licensed T-shirts


Go Back   TheDieselPage.com Forums > Chevrolet & GMC 2500HD/3500 Light Trucks > Duramax 6600
Register FAQ Members List Photo Album Mark Forums Read

Duramax 6600 Discussion Forum for the Duramax 6600 Diesel Engine, including the LB7, LLY, LBZ & LMM engine specific topics.

Reply
 
Thread Tools Display Modes
  #1  
Old 02-02-2006, 03:00 PM
markrinker
Guest
 
Posts: n/a
Post

I have yet to even pull the top plastic cover off my Duramax, but wondered if someone in the know could explain how the wastegate actuator works?

A quick glance today looks like it picks up boost from near the intake manifold and opens up the wastegate at a predetermined pressure to bleed off boost.

Wow...the 6.5 engineers sure overengineered boost control...(vacuum, sensor, solenoid...)

I bought a cheap boost valve that goes inline to fool the actuator. Must be a restrictor of some sort?
Reply With Quote
  #2  
Old 02-02-2006, 07:29 PM
Tough Guy
Guest
 
Posts: n/a
Post

Yes, the wastegate is pressure actuated...Kennedy has a nice little gizmo that "fools" the wastegate actuator.

The 6.5L truly is a engineering "gem"...


Chris
Reply With Quote
  #3  
Old 02-02-2006, 10:46 PM
DmaxMaverick DmaxMaverick is offline
Administrator
 
Join Date: Apr 2001
Location: CA
Posts: 10,622
Arrow

In spite of the engeering nightmare, the 6.5 wastegate control is far better, when working properly.

The LB7 wastegate will bleed off exhaust pressure as manifold pressure rises. This wastes energy, and causes a falloff of peak pressure.

The 6.5 wastegate control, on the other hand, will hold the wastegate closed until the trigger pressure is reached, then dumps the exhaust pressure to maintain it. On/Off. Way better. This is what JK's boost valve does, on the LB7, and it's adjustible.

Active control is almost always better than a passive control that relies on spring load, but the simplicity factor can win out.
__________________
1985 Blazer 6.2
2001 GMC 2500HD D/A
2014 Chevy Cruze Diesel
dmaxmaverick@thedieselpage.com
Reply With Quote
  #4  
Old 02-03-2006, 05:32 AM
markrinker
Guest
 
Posts: n/a
Post

JK how does your LB7 boost valve work? Is it a restriction to the factory line, or does it employ a check valve and spring to bleed off boost and maintiain peak as described?
Reply With Quote
  #5  
Old 02-03-2006, 08:42 AM
mcmonroe
Guest
 
Posts: n/a
Post

How is boost controlled on both the LLY and the LBZ? Via wastegate as well?

Mark
Reply With Quote
  #6  
Old 02-03-2006, 10:22 AM
DmaxMaverick DmaxMaverick is offline
Administrator
 
Join Date: Apr 2001
Location: CA
Posts: 10,622
Arrow

Quote:
Originally posted by Mark Monroe:
How is boost controlled on both the LLY and the LBZ? Via wastegate as well?

Mark
LLY/LBZ doesn't have a wastegate. The exhaust pressure is controlled by the VGT. The exhaust gasses are directed into the turbine by vanes, which are controlled by the PCM.
Reply With Quote
  #7  
Old 02-03-2006, 04:11 PM
Kennedy
Guest
 
Posts: n/a
Post

Quote:
Originally posted by Mark Rinker:
JK how does your LB7 boost valve work? Is it a restriction to the factory line, or does it employ a check valve and spring to bleed off boost and maintiain peak as described?
You really need to get around a bit more:

http://www.thedieselpage.com/reviews/jkboostvalve.htm
Reply With Quote
  #8  
Old 02-04-2006, 09:14 AM
markrinker
Guest
 
Posts: n/a
Post

I read that long ago - have you sold your million of 'em yet?

The $28 Ebay purchase I made is simply a restriction to the line. Not adjustable. I may relist it and buy one of yours after testing to see what pressures I get with this one.

http://cgi.ebay.com/ebaymotors/ws/eB...RK%3AMEWN%3AIT

What would you say the effective range of peak pressures are - with your adjustable unit - with stock fuel rate, exhaust, etc. ???

[ 02-04-2006, 07:28 PM: Message edited by: Mark Rinker ]
Reply With Quote
  #9  
Old 02-05-2006, 10:00 AM
Kennedy
Guest
 
Posts: n/a
Post

From little/no change to mid 30's which is too much for the stock turbo.

Adding the boost valve to the stock program/fueling will not give much if any power increase. You need the exhaust heat and throughput to make the boost come up. Put a little fuel on it with an Edge box and watch it do it's magic!
Reply With Quote
  #10  
Old 02-05-2006, 10:10 AM
markrinker
Guest
 
Posts: n/a
Post

My propane tank should be here this week and mounted/filled by week end.

The plan is to put all hardware, and software and your electronic EGT/boost gauge in place, and take the following measurements:

1) Stock EGT and boost - as a baseline
2) EGTs and boost with propane - MSD factory settings
3) EGTs and boost with inline restrictor

The next few weeks will be used to detail the mileage and power affects of running propane over diesel while towing. Hope to capture lots of statistics.

JK I may become an EFI Live customer if my testing leads me to modifying the OEM fuel map for the LB7. I am interested in reducing diesel and increasing propane proportions while in tow/haul mode ONLY. Is this possible?
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -7. The time now is 11:17 AM.


Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 1996-2014 by TheDieselPage.com - All Rights Reserved