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Would you recommend a gm turbo and spend the money for it? if so why or why not

DZZ71 said:
I would if they have no desire to improve or modify it and are happy with it as is. Other wise no I would recommend an up grade. The ******** or what ever it's called. Otherwise ****** if they really wanna do sum fabing.
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Man NO TURBO names that was the agreement at the start of this thread. GEEEZZZ now I have to plug the ***** turbo (telegraph turbo ) :) :)
 
great white said:
I'm not looking for an argument or a debate on the subject, so I will just say it depends.....

I've towed 35 feet of 8500 lb travel trailer from the west cost to the east through all the passes, winds and plains involved. Did just fine for speed and power on the gm8. One of the few pieces on the truck that hasn't given me trouble.

I'd also say I've pretty much found the upper hp limit on the gm8 in my truck. It's not as low as most people seem to think, even surprised me a bit.

I've now backed away from trying to squeeze every last HP out of the assembly. Life and goals change.

Chasing MPG.

The GM8 isn't as bad as most seem to think there also. Still working on that one and haven't found the limit there.

But it does require some time, work, understanding systems and cash expenditure .....the devil is in the details with these beasts......

But, for the price tag a new OEM replacement GM8 I will say there are better units for the money.

The ************ comes to mind and I eventually plan to try one out.

But those are mucho deniero.

Much more than the average 6.5'er is willing to spend......
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ABSOLUTELY NO TURBO NAMES :) :) here, we are not hawking turbos here just discussing the GM set of turbos.

I don't think anyone is saying it is a bad turbo mechanically, the turbo is just to small for our motor in my opinion. It is amazing at what a 6.5 can do when it can breath.
 
I agree. nothing wrong with the turbo itself, just not matched well to the 6.5

these gm turbos as twins i bet would kick ass! but obviously not as a single
 
OK :) nothing about any turbo other than the GM 3 4 5 6 or 8 that came equipped on the gm 6.5 liter after 1994. OK ")
 
Never a GM turbo again!! IMO they are a large part of the reason these engines have such a bad rep in both power and reliability.
 
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Meh, packaging.. That's all GM was worrying about.

.....aaaand saving a dollar fifty per unit.

Perfect turbo for a 200 horse engine..

Any other turbo the 6.5 wouldn't be a 200hp engine now, would it? :hihi:
 
buddy said:
Never a GM turbo again!! IMO they are a large part of the reason these engines have such a bad rep in both power and reliability.
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I know I am going to hate myself in the morning, and you better frame this post, I agree. That don't happen often, there I said it.:eek:
 
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I think the control scheme is great for mileage and response, instead of the plain pressure pot Dodge was using at the time, where you could open the waste gate under computer control for low back pressure cruise. Then snap it shut for spool up. But why for the life of me did they use that turbo? :???: Left over from another project? It was "close enough" so they went with it? We will never know, maybe just more bean counting that bit them in the marketplace.:rolleyes5:
 
L98TPI said:
I think the control scheme is great for mileage and response, instead of the plain pressure pot Dodge was using at the time, where you could open the waste gate under computer control for low back pressure cruise. Then snap it shut for spool up. But why for the life of me did they use that turbo? :???: Left over from another project? It was "close enough" so they went with it? We will never know, maybe just more bean counting that bit them in the marketplace.:rolleyes5:
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As with most automotive design there are alot of compromises The GM turbo was just that and for someone who doesn't tow and is happy the performance of the GM turbo its fine But once you do an upgraded Turbo you will wonder why you waited so long, the GM turbo is fine up to 2000 rpm but thats where it starts dieing and thats where the upgraded turbos shine
 
Im still running my GM-4 unit and its come long way since stock. For some reason my i cant ever get my EGT's over 1000 degrees even towing uphill. Im working it pretty good. Im going to swap to a different turbo soon, so i will feel the difference. Im sure looking at my GM4 while on the bench the exhaust looks very restrictive!
 
The GM turbo meets the AFR requirements, and its of good quality, just the wrong application. Turn up the fuel and boost and it starts going out of the requirements. It was probably an engineer making calcualtions, with an environmentalist touting the black smoke concern, and a bean counter sourcing turbos. From the computer calibrations for the DS4, it appeared that the designers originally had intended much more for this setup. Where they left traces that fueling was mapped to 96mm^3, but then limited to 80mm^3 and set to about 65mm^3, and boost limited to 22psi, 2.5-bar, but set to 8psi max with a 2-bar MAP. So along the way either engine failures or bean counters rained on their parade. When you look at the first 6.5td, it almost seems like a shade tree job, bore a block and slap on a turbo. The GM development bucks likely went into the heads, although they werent so great either. This was an era where American trucks ruled, but they were getting beat up on small cars, sedans, and luxury cars.

Look what dodge did as well, they went from large 18cm^2 housings to 12cm^2 housings. GM just went even smaller.
 
To the original question, No. While I do not have experience with anything but a GM8 (yet), the reasons for me to switch are:

> Need: Burb's turbo is visibly showing its age, so looking at a replacement on my schedule and not its.

> Cost: Some of the competition offer new units for about the cost of a reman GM8.

> Complexity: The GMX series uses a wastegate that the computer does not directly control (unless I am missing something), so I am looking at a unit that does not have one (not naming names) which reduces the number of moving parts.

> Performance: Am reading numerous real world posts where the GMX has a more narrow performance envelope than its competition within the same price range and a second effect benefit that the competition (numerous names not to name) tends to have better fuel economy and power.
 
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