Im just considering getting a tm, or replacing a bad wastegate solenoid. right now i have my vac line running straight into my wastegate actuator because of the bad solenoid. the funny part is my truck runs better than ever! i know, i know... its dangerous, but im driving it real gentle. trying not to build too much boost. just need some expert opinions. thanks

I put on a turbomaster a year ago, and would never go back.....

I've never had the vac system, since i bought my truck with a dead pump. I made a homemade TM. However the way i understand it, the vac system will dump boost around 2000 rpm in "crusing" conditions. I would assume this is done so the wastegate flops open, and relieves some backpressure in the exhaust, which saves fuel. However this means the boost is not there when it is needed, which might make a truck with a TM seem to have more power. It certainly should perform better...which is why your truck runs better with the vacuum hooked directly to the wastegate actuator. The TM basically does the same thing, but it is controlled by spring pressure which will at a set point stop producing boost at a certain level. The way you have it now there is nothing stopping it from making all the boost it possibly can.

I've read on here a few times about the vacuum system dumping a bit of boost while cruising which would obviously save some fuel, just curious if anyone has tried to quantify this and if it's significant?

Something died in my vacuum system too and its time to fix it just wondering which route to go.

I'm pretty sure something is wrong with my vac system as well. It will boost fine all the way to 80 km/h, then drop out of boost and just smoke. Eventually it will build boost again and stop smoking and actually go. It seems to do it a lot more when I'm towing something. Either the vac pump is going or the wastegate solenoid.

I had a TM on for a while and I can't say I noticed anything better or worse about it. I went back to the vac system, now I run a different turbo so I don't even run the vac system anymore.

well, in most cases its the solenoid. very common for this part to go bad. so common in fact that you'll find that they're hard to get. I just replaced mine and im happy with the way the truck runs. havent towed with it yet, so we'll see. but one thing i did want to add. there seems to be alot of hype about running your vac pump directly to your wastegate actuator. because it essentially locks it closed. but if your computer is stock, it wont allow you to over boost anyway, so whats the problem? any feedback would be appreciated. oh, and also, about the tm. why wouldnt a spring ran from a bracket to the wastegate work just as well? why do you need the rod?

A spring from a bracket to the WG would work if you could find a spring with the proper tension, but it takes a stiff spring. Also the computer controls boost by dropping vacuum to the WG. Take away the solenoid and hook the vacuum directly to the WG and the only way to control boost then is to raise or lower the fuel rate. When the boost hits a certain point the computer will cut the fuel rate back dramatically and you will lose power big time. Even in doing this, the spike of high pressure/high temperature boost can blow head gaskets or worse. This is why there has to be some sort of control over the boost system. If these weren't problems you could just weld the WG shut and never worry about it again but unfortunately that isn't the case.

I have only recently replaced my no functioning vacuum system with a Home Made TM and the difference is very noticeable, power on demand, better mileage and no more black smoke when going up the hills. I have not towed with the TM and this will be in a week or so and this will be the big test...... The boost is set at just under 8psi and this seems to be just fine.

When my vacuum system was working there was still not the power the we now have with the TM.

My EGT's dropped across the board 2-300 degrees by simply installing the Turbo Master.

That's difference enough to never think twice about it.

or

to put the question in another perspective....

Did GM do a wise thing when they eliminated the "Door Spring" and develop an ECM controlled boost. And was it such a bad move that the modern DuraBux trucks still use a mechanical control

NOT!!!!

Certainly the programing on the boost system of our trucks could use a little enhancing and Kennedy provides that in his performance chip, but is a mechanical control better???? --> If it was we still would have a throttle and a spark control on the steering column like a Model T Ford!

To the folks that have had great success with their door springs -- Of course you did! You "Upgraded" from an easily maintained system that (for some reason maybe age) was not working correctly and you didn't take the time to fix!

or
To the folks that have had great success with their door springs -- Of course you did! You "Upgraded" from an easily maintained system that (for some reason maybe age) was not working correctly and you didn't take the time to fix!

The first time my pump went out, I changed it.(changed boost solenoid
and actuator as they went out over the years too, at different times, $$)
The new pump lasted about 2 years. Rather than sink more money into
it, I made a TM for about 5 - 10 dollars, and I'll never have to spend money
on it again. I didn't see any gain or loss in mileage or performance, and
when my vacuum system was in good shape, I had no complaints, it
worked great - but from a reliability / cost standpoint, TM wins hands down.

I put on a turbomaster a year ago, and would never go back.....
x2 and my vacuum system was working perfectly or as well as gm designed it. it's also one less thing to worry about as it will fail eventually. Ed

I was very happy with my TM and consider it as a true upgrade, not a gadget.
The only thing wich made me taking it out is my new turbo wich is non-wastegated.

if you can find a new wastegate solenoid how much does it run you?

mine was 47 dollars

tell you what, i towed with mine today and was very happy all the way around. uphill, the whole bit. what i think is going on here is even if your wastegate solenoid isnt completely shot, its probably not working 100% correctly and thats why people are so unhappy with the stock vacuum setup. the solenoid has a metal ball inside that corrodes and its a slow process. if anyone is experiencing erratic boost or lack of boost when you need it, and you know your vac pump is good and your actuator is good, then get a new solenoid and i bet you'll notice a hell of a difference.

tell you what, i towed with mine today and was very happy all the way around. uphill, the whole bit. what i think is going on here is even if your wastegate solenoid isnt completely shot, its probably not working 100% correctly and thats why people are so unhappy with the stock vacuum setup. the solenoid has a metal ball inside that corrodes and its a slow process. if anyone is experiencing erratic boost or lack of boost when you need it, and you know your vac pump is good and your actuator is good, then get a new solenoid and i bet you'll notice a hell of a difference.

Good point:beerchug:

A wise man once suggested to me that each spring and fall I should dribble a couple of drops of air tool oil into the solenoid to lubricate that metal ball and keep the solenoid healthy!

Good point:beerchug:

A wise man once suggested to me that each spring and fall I should dribble a couple of drops of air tool oil into the solenoid to lubricate that metal ball and keep the solenoid healthy!

That's a great Idea.

I made my own turbomaster at work a little while ago, and put it on the truck... I was actually kinda disappointed to be honest.

The truck would defuel ONLY after cruising on the highway with boost levels up near 7-8 psi @ 2200 RPM doin 120 KPH

I had it all the way up to a spike of 18psi then down to 15psi sustained @ WOT, and never had a problem with it defueling (Never even threw a code) but something about the highway cruising it didn't like.

I never noticed any real kick in the ass in the higher rpms.

Now with the stock vac system I'll get 13psi sustained till 2000ish RPM then it'll bleed off to 10psi from 2000-2200, then down to 8psi from 2200 - 3000 and slowly bleeds off to about 3-2psi as rpm climbs.

Crusing on the highway, I've noticed that boost only bleeds off once it gets above 2200 RPM which puts me at 120KPH. Before it bleeds off, it'll be as high as 5psi

Now... Believe it or not, according to some calculations I've done, those readings are about on par for the power ratings that the 6.5 is rated for in stock tune. Air in, is air out, you make the power with more fuel, and supply more air as needed to burn more fuel that is added.

I guess I'll have to see if there is any difference with a reflashed ECU.

For now, I'm stickin with the Vac system

A little WD40 also works. With the truck idling pull the line off of actuator spray some in the end. After I replaced the wastegate solenoid I started doing this after it was recommended by Kennedy and have had no problems since.
At 125,00, I am still running original vacuum pump and actuator and on 2nd control solenoid. I know it will probably die one day but so far the vacuum system has been as if not more reliable than the rest of the truck. The first motor cracked block at 70,000. It was dumping coolant in oil that turned it into black jello. That clogged the turbo feed line and destroyed it too. It was replaced with a AMG motor under warranty by dealer (kinda).The new motor developed a tick that turned into a knock at 123,000. That turned out to be a wrist pin. The rear end was rebuilt under warranty. I am on 2nd alternator, pitman arm, steering box (under warranty) and idler arm. Some of the ball joints and tie rod ends have been replaced twice already. Just installed 3rd injection pump. The first was installed by dealer and was most likely a bad PMD (on my 3rd one of these too). Maybe I've been lucky with the vacuum system but from my perspective, It's one of the most trouble free parts of the truck.

Let your wallet and comfort level be your guide. I had dutifully replaced the WG solenoid when it started to act up ($52). When the vac pump died, I investigated the cost of a new unibelt and $15 for parts to a TM, versus a new pump and belt.
My TM maxes at 12psi, and works smoother than the pulsing WG sol. from the General. I get 1 to 1.25 better mpg, smoother power and lower cost. Not a tough decision. Now, if I get a boost code SES, parts are cheap and available at any hardware store.
How about a survey about this?

I now have a tm and gle 4 chip from heath diesel and wold never use my vac pump and solenoids again. Big difference in performance but I also am chipped.