D-Max turbo on a multi-fuel?

[Lonesome715]

I just happen to have a lower hour turbo from a late model Duramax. Before I try to sell it I was kicking around the possibility of installing on my M35. Any thoughts on this?

 

[VPed]

I do not have any thought on whether it is a workable combo but I would like to know what you were intending to do with the variable vanes.

 

[Lonesome715]

And that is one of the concerns I have. I know this is not a bolt on thing. But I thought it would be a interesting topic for conversation. Adapting this turbo would be tough.

 

[gary1978]

I think turbochargers need to be matched to the application, at least as far as the parameters of displacment, RPM (for total mass flow rate) and boost pressure. Given that the M35 engine is about 50% larger in displacement than the Duramax, I doubt that any substantial performance benefit is likely. I think this falls under the category of "interesting but not useful". There are many negative outcomes that can result from a turbocharger missmatch. One of them is blowing up a turbocharger that is too small for the application. When turbochargers do centrifugally "explode", the damage they can do is extensive. This was more common in the early years of automotive tubocharger experimentation, before they became more common, and sized appropriate to the application.

 

[Lonesome715]

I agree with your point. However, the one reason I was thinking this "might" work is because the Dmax turbo is larger than the Multifuel turbo. For a lack of a better turn, bigger is sometimes better.

 

[welldigger]

The turbos for the multifuel are actually very low flow for a turbo charger. I would be more concerned about the affects of the d max turbo forcing way more air in than what the multifuel was designed to handle.

All that being said, I say go for it. Never hurts to tread new ground. Well, I guess you are risking your engine, but hey, there's risk in everything.

 

[Castle Bravo]

... Given that the M35 engine is about 50% larger in displacement than the Duramax...

Its only about 15% more displacement.

Duramax 6.6L = 402 cu in
LDT465 7.8L = 478 cu in

I don't have any additional information.

 

[Lonesome715]

In my opinion... The multi can handle a larger turbo that stock. Now, how much larger I cannot say. I was kicking around the Dmax turbo because I have it on a shelf collecting dust. But, I also have a turbo from a 97 7.3 Power stroke. That one is a bit easier to adapt to different applications.

 

[Jeepsinker]

Its only about 15% more displacement.

Duramax 6.6L = 402 cu in
LDT465 7.8L = 478 cu in

I don't have any additional information.

Beat me to it.
I say try it if you have the time to waste. I feel sure it isn't going to work, but we may all learn something from your experiment. As far as the variable vanes, just fix them in a position you are temporarily comfortable with.

 

[HanksDeuce]

Keeping going bigger on the turbo selection until the engine blows. Then back down by one size smaller. Now about that blown engine...

 

[patracy]

In my opinion... The multi can handle a larger turbo that stock. Now, how much larger I cannot say. I was kicking around the Dmax turbo because I have it on a shelf collecting dust. But, I also have a turbo from a 97 7.3 Power stroke. That one is a bit easier to adapt to different applications.

Larger? Sure.

But there's a number of factors you're glazing over.

1. Turbine housing size
2. Turbine diameter
3. Twin or single scroll turbine (Only a single could really be used in the multi due to the exhaust manifold)
4. Compressor inlet diameter
5. Compressor outer diameter
6. A/R ratio and compressor map

Get one or some of these wrong, and even with a "larger" turbo, performance will be worse. Another thought to consider is the maps at which a modern turbo runs. 25psi might be perfect for that duramax. But you'll have multifuel guts on the ground before long.

 

[Lonesome715]

We all know everything on the internet is true. That being said, a video I saw on the Hot Rod channel on You Tube got my attention. They took a mostly stock 4.3 Chevy Vortec gas engine and installed a stock turbo from a 7.3 Power Stroke on it. It ran great on the road and race track. According to them, nothing was done to the engine or the turbo to make them work together. The turbo was an after thought. If there is any truth to that it got me thinking "maybe" matching a turbo to an engine might not be as complicated as I thought.

 

[jrobinson5093]

With the VGT you might could adjust it to spool up quick and add a boost control valve to limit the psi to the engine. One could probably add some type of cable to the VGT mech and make it adjustable on the fly. They can even be used as a exhaust brake. I say try it but take the proper steps to be safe with the engine.

 

[Lonesome715]

Now that sounds like a good plan.

 

[rustystud]

I would not even own a "variable vane turbo " ! We replace these on the "Cummins ISL" at about 25,000 to 50,000 miles. They have a tendency to come unglued ! They have been the worst turbo we have ever had ! The variable vane is just for emissions, so I would steer clear of it .

 

[Lonesome715]

I can see that being true.

 

[jrobinson5093]

I see the VGTs on power stokes and duramax. The system does wonders for helping to spool quicker. But I still prefer the fixed vane.

 

[Lonesome715]

I think for a project like this a fixed vane is the way to go.

 

[Jeepsinker]

Yeah, working at the dealerships we were constantly replacing variable vane turbos. Luckily for the owners they were all still under warranty. Usually around 20,000 miles, but some as low as 12,000. They are expensive too! Just sell the one you have, you'll make good money. Then buy a REAL turbo... Not junk designed to keep you buying parts or buying a new truck.

 

[patracy]

I would not even own a "variable vane turbo " ! We replace these on the "Cummins ISL" at about 25,000 to 50,000 miles. They have a tendency to come unglued ! They have been the worst turbo we have ever had ! The variable vane is just for emissions, so I would steer clear of it .

Unglued or glued completely up!

Bigger is not always better. Especially on a sub 200hp engine.

I know of people who've installed larger turbos on LDTs. But they've gone back to a C or D turbo.