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vacuum boost controler

dkanderson

dkanderson

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Gastonia NC
Can you run a vacuum boost controler on the 6.5l i just dont understand why you couldnt, Ive had turbo cars that ive made a vacuum boost controler and i just dont see why it wouldnt work for the 6.5 maybe no body knows about them?
 
dkanderson said:
Can you run a vacuum boost controler on the 6.5l i just dont understand why you couldnt, Ive had turbo cars that ive made a vacuum boost controler and i just dont see why it wouldnt work for the 6.5 maybe no body knows about them?
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What are your thoughts;
As AKDD says they come from factory this way, boost on Diesel is different from a gasser we have no throttle plate to go shut on us, so no need to limit how much boost we get, our limits are within the confines of the ability of the turbos ability to create boost, OEM routine limits boost by opening our normally closed WG to reduce amount of drive gas to the turbine of the turbo, so if we need less boost the wg is opened and turbo boost production decreases.

Several methods to increase boost via fooling the PCM from knowing how much boost is being made so it does not open the wg before we want it to, or reprogramming the PCM, mecahnical WG regulation via purchased or "home brew" turbo master(which may require fooling/program to keep from setting a boost code) or re-chip PCM to allow for more boost. Some of us have gone to turbo with no wg that is a better producer of boost than the one supplied from GM. There are limits, because there is only X pressure the cylinder/head can tolerate when combined with boost when at high power.

Nominal sustained boost, 6-7 psi with excursions to 15 psi boost are design by GM, and generally give best life for the 6.5, some of us run to 20 psi sustained with engines set up to run higher pressures adding extra cooling via WMI or ICs, even then that is pushing longevity envelope, I find with my ATT 10-11 psi is all I need to run 100+ mph running empty. When towing heavy I self limit to 12-14 psi excursions, with GM turbo once you get above 10 psi it's internal flow characteristics it starts becoming diminished return IAT climbs very fast as well with higher boost from the turbo adding extra heat the engine has to deal with.
 
Good info, well i got bad news on my truck i hooked a gauge up and its reading 0 boost even when im flooring it, i did hook the gauge to the vacuum line that goes to the WG i dont know if thats right? but it seems like the WG stays open i can move it up and down very easy and i took the vacuum line off the WG and it dont feel like there is any vacuum at all, any info would be great thanks
 
I just ziptided the WG shut and still no boost on the gauge and still cant hear the turbo spooling at all, i think it is a bad vacuum line or pump. Not really sure where i go from here, wouldnt it still boost if i ziptided it shut? or maybe cuz theres a broken vacuum line its not showing up on the gauge....
 
Mine was the same way when I bought it. I put a TM on it and had little to no boost. I t ended up being that it wouldn't close fully due to soot built up on the WG flapper. I took the TM off and opened and closed it manually about 30/40 times until it stated making a metal on metal tinking sound. Then hooked the TM up and took it for a ride and had boost. I believe that it had been inoperational for a long time and built up soot that kept it from sealing.

Anyway, if it is wired shut you should be getting boost, you are bypassing the vac pump and solenoid by doing this. You may also have shaft end play that is keeping the flapper from sealing. That is what happened to mine after six months of use. Check the linkage by wiggling it and see if it goes side to side. Ultimately you may have to take it off and pull the rear housing and check/clean it. Hope this points you in the right direction.
 
robzombie4551 said:
Mine was the same way when I bought it. I put a TM on it and had little to no boost. I t ended up being that it wouldn't close fully due to soot built up on the WG flapper. I took the TM off and opened and closed it manually about 30/40 times until it stated making a metal on metal tinking sound. Then hooked the TM up and took it for a ride and had boost. I believe that it had been inoperational for a long time and built up soot that kept it from sealing.

Anyway, if it is wired shut you should be getting boost, you are bypassing the vac pump and solenoid by doing this. You may also have shaft end play that is keeping the flapper from sealing. That is what happened to mine after six months of use. Check the linkage by wiggling it and see if it goes side to side. Ultimately you may have to take it off and pull the rear housing and check/clean it. Hope this points you in the right direction.
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Thanks for the info, Im kind of going crazy about it hoping its not a bad turbo or somthing i am going to put a TM on it very soon, and im going to tap my intake so i can put the gauge in that way..

I was thinking if the turbo was not boosting it would blow black smoke really bad but this truck dont smoke at all even when ur getting on it.......
 
A common failure point for the vacuum system is the solenoid that is controlled by the ECM and I'm willing to bet that's your problem.

It's the black component on the drivers side just above the valve cover. It looks like:

55-ALT0-20041005133614.jpg


Anyways, here's how to check the system.

Step 1. Check the wastegate arm of the turbo at idle. If the wastegate arm is not rock solid at idle, you have a vacuum problem somewhere.

Step 2. Pull the vacuum line off the solenoid ( black thingy over the valve cover on drivers side) and make sure there's vacuum there. It should be around 20 in/hg. If none (or very weak) you have a bad vacuum pump or the line from the pump to the solenoid is cracked and leaking. If it's good, move to step 3.

Step 3. Pull the line off the turbo wastegate actuator and check for vacuum. If none, you either have a bad solenoid (black thingy again) or the line from the solenoid is bad and leaking. If it's good go to step 4.

Step 4. If the pump lines and solenoid checked out good and the wastegate actuator arm is not rock solid at idle (I can't even get mine to budge) the vacuum pot on the wastegate is probably bad.

From your description, it sounds like you pulled the line of the turbo wastegate vacuum pot and tried to measure boos there. I that is what you did, you weren't measuring "0" boost, you were measuring "0" vacuum.

Unless you tapped a fitting into the intake, there is no easily available port to measure boost....
 
Slightest cracked open WG will dump boost, zip tie probably letting it open just enough to not make boost, bailing wire pulled tight that can't give, is what you need to hold it shut, and shut is with the arm & rod pulled all way into the vac canister.
 
Im going today to get the parts i need to make a turbo master, i pulled the wastgate rod off today and i still gotta tap the intake for the boost gauge, I think im going to take the tube off the turbo and the intake and drill it that way so i dont get shavings in the intake.

I feel like a dumbass that i hooked the gauge up to that vaccum line, i should of known its not going to show any boost lol oh well live and learn, ill let you guys know how the turbo master turns out
 
Boost tap location where I put mine, so just upper intake comes off, not knowing your background remember and for those observers that have never tapped before, it's NPT taper for the fitting so don't thread all way through like with a bolt tap, or it won't seal correctly.

Top of intake.jpg
 
PMDCABLE.COM sells a 'boost bolt' that replaces one of the upper intake bolts and it has the tap. Very easy great idea, no drilling. Check it out.
 
Matt Bachand said:
PMDCABLE.COM sells a 'boost bolt' that replaces one of the upper intake bolts and it has the tap. Very easy great idea, no drilling. Check it out.
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Thanks for the link that is a really good idea but for 30 bucks ill just tap it i have a buddy that knows all about this kind of stuff he did my boost controllor today cost me a total $8 cant beat that, seems like all the parts for the turbo for this truck are way over priced i mean $120 for a boost controllor that was built for maybe 20 bucks i mean come on.....


I also opened and closed the WG flap and when its fully open it gets stuck and you have to tap it with a hammer to get it to move again.......I am going to wait till i get the gauge taped in before i run the truck with this boost controllor cuz i dont want to be puting out alot of boost and not know it.
 
If it's getting stuck either it's carboned up and you need to remove it to de-gunk it, or the WG arm/lever bushing is bad and it's binding up on that, if bushing is bad then you need to start looking for a "used but good" replacement turbo from one of the guys that have swapped to the ATT turbo, or get a ATT for yourself, you will not be disappointed with that decision.
 
dkanderson said:
Man i dont want to have to buy a new turbo.....
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Let's hope not or at least not until you are ready, but if it's the bushing there hasn't been a good fix for that other than replacement, but at least the A Team turbo is reasonably priced new turbo replacement with better performance than GM turbo for less than the GM one can be found new or even as a rebuilt turbo.
 
Turbine Doc said:
Let's hope not or at least not until you are ready, but if it's the bushing there hasn't been a good fix for that other than replacement, but at least the A Team turbo is reasonably priced new turbo replacement with better performance than GM turbo for less than the GM one can be found new or even as a rebuilt turbo.
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Do you have a link where i could find this ATT turbo at? that way i can get a price
 
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