Truckers, lets see your rigs!

[jfaulkner]

Originally Posted by Signature600

Mitigate increased heat/pressure?? You mean on the engine you're running at 2-3 times factory power levels? Turn it back down...

Lmao, so you mean to tell me I probably won’t get a million miles out of this engine without an overhaul or 5? I’ve had it apart at least once in the first 10k miles but I like to do very thorough oil changes.

[Signature600]

Originally Posted by allan5oh

I always thought thrust forces were related to pressures not pressure ratio. Both inlet air and exhaust outlet are going in the same direction, thrust forces would be in the opposite direction?

How does 1:1 relate to turbo efficiency?

edit: We can calculate shaft HP from the compressor map.

If you know, why are you asking?


Since you can't understand what I meant, and I didn't type it 100% correct. 1:1 is letting you know how efficient your turbo system is. Meaning, does the whole thing, as a whole, breathe or choke.

Chris

[Signature600]

Originally Posted by jfaulkner

Lmao, so you mean to tell me I probably won’t get a million miles out of this engine without an overhaul or 5? I’ve had it apart at least once in the first 10k miles but I like to do very thorough oil changes.

Maybe if you drove for BSFC instead of trying to get your a$$ home faster

Chris

[jfaulkner]

Originally Posted by Signature600

Maybe if you drove for BSFC instead of trying to get your a$$ home faster



Chris

The day I have to worry about BSFC’s is the day I’ll get a real job.

[allan5oh]

Originally Posted by Signature600

If you know, why are you asking?


Since you can't understand what I meant, and I didn't type it 100% correct. 1:1 is letting you know how efficient your turbo system is. Meaning, does the whole thing, as a whole, breathe or choke.

Chris

Know what?

is a 1:1 system automatically more efficient than one that isn't?

What are we talking about efficiency here?

edit: "I always thought" <> "I know"

[allan5oh]

At this point it's entirely possible there should be more doing on my part than thinking.

[Rig Wrench]

Seem to argue alot for a guy havin issues with a sub 500 hp truck. Maybe it just comes off like that. Idk

[allan5oh]

Not sure where the arguing is?

[jfaulkner]

Originally Posted by allan5oh

edit: We can calculate shaft HP from the compressor map.

Not a lot of large frame Holset compressor maps laying around. I prefer the try it method. 3.2" compressor wheel on manifold turbo was good but thanks to SOMEONE spending money for me I got a 3.6" on it now to try and since dyno day was a bust I'm going to use my mobile dyno and use fleet trucks like yours to compare performance.

[chevota84]

Originally Posted by allan5oh

I always thought thrust forces were related to pressures not pressure ratio. Both inlet air and exhaust outlet are going in the same direction, thrust forces would be in the opposite direction?

How does 1:1 relate to turbo efficiency?

edit: We can calculate shaft HP from the compressor map.

Thrust is axial, not radial. 1:1 will be near equal force towards the center of the turbo no matter what the pressure is.

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[BRE]

I prefer factory turbos.


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[jfaulkner]

Originally Posted by BRE

I prefer factory turbos.


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There really is nothing better than OEM. That goes for anything from turbos to boobs.

[biggy238]

1:1 has no basis in thrust values, unless you want to get all engineer level and calculate surface area acted upon on.

Opinion: 1:1 ratio has no basis in fact. The mass having work imparted to it and the mass imparting the work are only loosely connected by the turbine shaft. You would have to calculate enthalpy of the exhaust gas stream across the turbine, and calculate the power needed to flow/pump inlet air at any given point of operation. Pressure alone is far from an indicator of the efficiency of the turbocharger as a system. Calculate power in vs power out.

I would like to read if someone has published information to contradict my opinion. I've never had a reason to look in to it either way. I just (think I know) the energy available to the turbine and what's being imparted into the inlet air mass are so wildly different that it's not reliable to use pressure.

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[Rig Wrench]

Originally Posted by BRE

I prefer factory turbos.


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Just disregard that boost gage

[chevota84]

Originally Posted by biggy238

1:1 has no basis in thrust values, unless you want to get all engineer level and calculate surface area acted upon on.

Opinion: 1:1 ratio has no basis in fact. The mass having work imparted to it and the mass imparting the work are only loosely connected by the turbine shaft. You would have to calculate enthalpy of the exhaust gas stream across the turbine, and calculate the power needed to flow/pump inlet air at any given point of operation. Pressure alone is far from an indicator of the efficiency of the turbocharger as a system. Calculate power in vs power out.

I would like to read if someone has published information to contradict my opinion. I've never had a reason to look in to it either way. I just (think I know) the energy available to the turbine and what's being imparted into the inlet air mass are so wildly different that it's not reliable to use pressure.

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A lot of that is over my head, however, wouldn't the 1:1 ratio lead you to believe that the forces are close to balanced? If the turbine housing is too tight or the wheel is too small, you'll see a much higher drive pressure number vs boost, the same if there's an intake restriction. When it gets a higher than 1:1 ratio you're seeing an inefficiency on one side or the other of the turbo, it's taking way more power than its producing.

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[allan5oh]

Originally Posted by chevota84

Thrust is axial, not radial. 1:1 will be near equal force towards the center of the turbo no matter what the pressure is.

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Yes so we can ignore the exhaust inlet and air outlet. The air inlet wants to climb the air, think of it as a propeller. If it was spun right up and let loose at high rpm (no housing or cover) it would launch forward at a high rate of speed.

Wouldn't the turbine do the same? It is expelling mass out the rear. That means the opposite force is forwards. So IF this is true, that means 1:1 drive to boost is irrelevant when it comes to axial thrust.

[allan5oh]

Originally Posted by chevota84

A lot of that is over my head, however, wouldn't the 1:1 ratio lead you to believe that the forces are close to balanced? If the turbine housing is too tight or the wheel is too small, you'll see a much higher drive pressure number vs boost, the same if there's an intake restriction. When it gets a higher than 1:1 ratio you're seeing an inefficiency on one side or the other of the turbo, it's taking way more power than its producing.

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Two scenarios I see:

1) VE of the engine is affected by the rise in back pressure. This causes the compressor map to shift to the left for the same pressure ratio. Not good.

2) VE of the engine is NOT affected by the rise in back pressure. This means the compressor side is not affected, it is exactly as efficient as 1:1 which means the TURBINE side has lost efficiency. This can probably measured by the temperature difference pre and post turbo.

Again these are just thoughts, I have no empirical data.

[BRE]

Originally Posted by jfaulkner

There really is nothing better than OEM. That goes for anything from turbos to boobs.

Words to live by there!


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[jfaulkner]

Originally Posted by BRE

Words to live by there!


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Actually I couldn’t leave those stock either, bigger is always better.

[zfaylor]

Originally Posted by chevota84

A lot of that is over my head, however, wouldn't the 1:1 ratio lead you to believe that the forces are close to balanced? If the turbine housing is too tight or the wheel is too small, you'll see a much higher drive pressure number vs boost, the same if there's an intake restriction. When it gets a higher than 1:1 ratio you're seeing an inefficiency on one side or the other of the turbo, it's taking way more power than its producing.

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It would appear that way on the surface but as kyle was getting at it is an arbitrary number when comparing a given turbine and compressor. Two entirely different designs. Different blade count, architecture, conditions (temperature), etc. More times than not bearings aren't the issue. It is overspeed and/or lack of oil supply. That doesn't necessarily mean the engine isn't keeping up so much as orifices and internal metering isn't supplying enough.