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to turbomaster and vac pump delete or not?

C

copperhead232

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Hi to all. Got a 98 C3500 dually crew with a vac pump that sounds like a sack of marbles, guess the bearings are giving up the ghost. Question is I've got access to a freebe homemade tm and was kinda looking for some outside opinions on going that route and canning the pump rather than replacing it. I got an "f" motor and do a considerable amount of towing in the WV mountains. Took 3 xays to get a reply to this on that other 6.5 website and was basically told I was an idiot. Any constructive help is greatly appreciated.
 
Most ditch the vac system after a few Vac pumps, solenoids, etc.

Just make sure you have a boost gauge to set it, and keep an eye on it, while your on those upward grades.
 
I built my own TM when the vac pump went, I didn't notice a loss in mpg but it towed much better.

Now I'm wastegate free.
 
The loss in MPG typically comes from not realizing when you set them up for too much max boost that your min boost is too much when cruising. In this way the TM sets your max and min boost. You dont want more boost than you need when cruising, and 2-3psi is enough cruising around on flat land. So if you set up your TM for a cruise boost rather than a max boost it will work better and actually match the boost you need for the given fuel range you have. I prefer the vac system, and it works fine when its working, never had any trouble keeping it going for a few years I used it, had to patch the plastic lines a couple times, easy enough for a system installed in late 93. The original vac pumps seemed to last a long time, rebuilts not so long, but you can get new from PMDcable. The solenoids aren't expensive. The stock boost curve leaves a lot to be desired, which usually makes people change to mechanical control. If you get an aftermarket program you can ask them to set it up for load based boost, where it drops at low fuel rates and mid-high rpms and simply increases with fueling to the max boost you want.

Of course its hard to break a rod and spring, so its not going to quit on you. So if you want that ultimate reliability I just suggest setting the controller for low interstate cruise boost when not towing, and the acceleration or loaded boost will match whatever fueling you have to support.

And ultimately, I would lose the GM turbo all together :)
 
Agreed with the above...For towing and reliability go TM and delete. Daily driving and econonmy, stick with the factory vac system.

-Nick
 
Just curious if one as Buddy says sets the TM for a minimum boost of say 2-3 for economy what would the max boost be? Anyone got hard numbers on this?

Cheers
Nobby
 
I set mine up for 3psi at sea level and cruising 55. At a good hill empty it would climb to 6 to 7psi. With the 5er on it would cruise at 3 to 4 psi and climbing it would hit 6 to 9 psi. Now that I'm at 3000', cruise at 65 it's at 3 to4 psi and will climb to 10 to 12 with a hard throttle. I have noty checked it pulling here yet.
 
Ok folks, got the homemade tm in and working. Boost is running 3-4 lbs cruising at 65 and 11-12 at WOT. Hookedup and moved a horse Sunday and pulling hard at 55 it would consistantly defuel if I allowed boost to allow over 11 for any length of time. I built myself a boost fooler and installed it. Now the question is, how do you adjust it. It doesn't light the ses at any setting. Can it be set strictly by resistance? Thanks
 
copperhead232 said:
Ok folks, got the homemade tm in and working. Boost is running 3-4 lbs cruising at 65 and 11-12 at WOT. Hookedup and moved a horse Sunday and pulling hard at 55 it would consistantly defuel if I allowed boost to allow over 11 for any length of time. I built myself a boost fooler and installed it. Now the question is, how do you adjust it. It doesn't light the ses at any setting. Can it be set strictly by resistance? Thanks
Click to expand...

I think all you are really setting it for, now that you have a turbomaster, is to NOT defuel. As long as you don't get a SES light (and watch your boost gauge) you should be GTG.
 
It only codes after 10 seconds straight of boost over 3psi off the curve. So thats why it codes when pulling and never when not. How often do you sustain 11psi for more than 10seconds?
 
Welcome to TTS!

Is your towing for recreation or profit? If you do a lot of towing your MPG becomes important enough that you can justify replacing the turbo with a bigger one along with supporting mods like a tune and exhaust in 15,000 miles.

The GM turbo is simply wasting fuel over 2200 RPM making the cooling fan run and eating power. Check the 6.5 performance section for dyno results of a larger turbo under towing/full load. It is worth over 50 HP and torque past redline.

I have towed hard, hot, and heavy with my 6.5 and sent a couple of 6.5 engines to scrap metal. My biggest problem was the GM3 turbo followed by the cooling system unable to get rid of the heat trapped by the exhaust restriction of the GM3 turbo. My biggest regret is F#*&ing around with turbo masters rather than just ripping out the turbo for a bigger one. But at the time info was not easy to come by about it. The Turbomaster allowed more MPH over the 1993 factory spring can - not sure if it does much over 'newer' vac systems.

So towing in mountains with a larger A Team Turbo got me: less cooling fan use, 10 MPH faster (from 43 MPH to 55 MPH), 3 MPG increase (7 to 10.4 MPG), and payback in fuel saved of $1500 invested in A Team Turbo, 4" exaust/converter, and tune in 15,000 miles of towing. This is with a 24-28' trailer on 7% grades in 32 to 114 degree weather.

So cheap turbo master spring fix or expensive fix that gets you more power and MPG towing and pays for itself...

There are other bigger turbo's out there as well. Feel free to discuss them on here as we are allowed to :thumbsup: Again Welcome to TTS!
 
Hi to all. Got a 98 C3500 dually crew
Click to expand...

Also your pushing a bigger/heavier truck than most, not to mention more rolling resistance (Dually).......

As stated above you would benefit a considerable amount from a bigger Turbo in all the performance and Daily driver areas....Just remember even the latest GM-8 turbo, was/is barely up to the task in a regular 1500 series pick-up.

Also, Welcome to TTS.....Please fill out your signature so we all know what Flavor of 6.5TD you have.

JMO
 
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