Blown diesel?

[WrickM]

I understand how a turbo and a supercharger work. Point being the idi would'nt need alot of boost and the boost would be all through the rpm range.

It's just an idea, I may buy another holset VGT and cobble something togather at somepoint.

a centrifugal blower like the procharger tends NOT to give added power throughout the rpm range. As rpm's increase and decrease so does the boost. i have a eaten M112 roots blower that i was toying with putting on the engine in a semi-remote mounted manner, but i need my ac too much

 

[SparkandFire]

Quoted from http://en.wikipedia.org/wiki/Turbocharger

"A turbocharger is a small radial fan pump driven by the energy of the exhaust gases of an engine. A turbocharger consists of a turbine and a compressor on a shared shaft. The turbine converts exhaust heat to rotational force, which is in turn used to drive the compressor. The compressor draws in ambient air and pumps it in to the intake manifold at increased pressure, resulting in a greater mass of air entering the cylinders on each intake stroke"


Also links to-

http://en.wikipedia.org/wiki/Heat_engine

 

[Knuckledragger]

Quoted from http://en.wikipedia.org/wiki/Turbocharger

"A turbocharger is a small radial fan pump driven by the energy of the exhaust gases of an engine. A turbocharger consists of a turbine and a compressor on a shared shaft. The turbine converts exhaust heat to rotational force, which is in turn used to drive the compressor. The compressor draws in ambient air and pumps it in to the intake manifold at increased pressure, resulting in a greater mass of air entering the cylinders on each intake stroke"


Also links to-

http://en.wikipedia.org/wiki/Heat_engine

Be careful about relying on wikipedia too much. Heat alone cannot drive the turbine, and did you even read the entry about heat engines? Heat is not the friend of turbocharging, but is impossible to divorce. If it was good, we should be happy that the lubricating oil in the shaft bearings gets coked up.

 

[SparkandFire]

Yes I did read about the heat engine...

And what I referenced from wikipedia was just that, a reference. The information I was trying to convey was what I learned in thermodynamics and physics classes.

Not trying to be a smart ass, and I wasn't trying to make a personal attack on anyone.

What you are describing is true, to a point. The concept that a turbo is simply a "mass flow" device, and not a heat engine is incorrect. The turbo is capturing the thermal expansion energy of the hot combustion gasses. That constitues a heat engine.

If you don't believe me, install a thermocouple before and after the exhaust ports on a turbo... there WILL be significantly less heat after the turbo than before. Where does that heat go? It is converted to kinetic energy (mechanical work) and drives the compressor wheel.

Energy can neither be created nor destroyed. If the mass flow of exhaust gas was the only driving force behind a turbo, you would have LESS than equal boost pressure in direct proportion to exhaust pressure... for example, 9 psi boost pressure would require 10 psi exhaust pressure with %90 efficency (must account for frictional loss on the bearings and air flow in the housing)

 

[sootman73]

Yes I did read about the heat engine...

And what I referenced from wikipedia was just that, a reference. The information I was trying to convey was what I learned in thermodynamics and physics classes.

Not trying to be a smart ass, and I wasn't trying to make a personal attack on anyone.

What you are describing is true, to a point. The concept that a turbo is simply a "mass flow" device, and not a heat engine is incorrect. The turbo is capturing the thermal expansion energy of the hot combustion gasses. That constitues a heat engine.

If you don't believe me, install a thermocouple before and after the exhaust ports on a turbo... there WILL be significantly less heat after the turbo than before. Where does that heat go? It is converted to kinetic energy (mechanical work) and drives the compressor wheel.

Energy can neither be created nor destroyed. If the mass flow of exhaust gas was the only driving force behind a turbo, you would have LESS than equal boost pressure in direct proportion to exhaust pressure... for example, 9 psi boost pressure would require 10 psi exhaust pressure with %90 efficency (must account for frictional loss on the bearings and air flow in the housing)

X2

 

[SparkandFire]

More reading on the subject...

http://physics.bu.edu/~duffy/py105/Firstlaw.html

 

[oly_fab]

Sparkandfire is rite on the heat helping the turbo, otherwise you'd want to cool the exhaust instead of heat wrapping it. BUT were not talking about turbos were talking about blowers.



1. duall charging is done with positive displacement blowers like an eaten or whipple, not with a centrifugal blower. A Centrifugal blower spools kinda like a turbo in that time is required for the turbine to create the pressure differential.

WrickM, I'm not so sure about this. It may be that it does to some extent, but it would'nt be as bad as a turbo's lag. A turbo just sort of free wheels along till the exhaust gases spin it enough to build boost. Where as if it were belt driven it could be rite on the edge of building boost at idle.

As far as a turbo being cheaper...I think that I could build something like this for under $400.

Stu

 

[WrickM]

Sparkandfire is rite on the heat helping the turbo, otherwise you'd want to cool the exhaust instead of heat wrapping it. BUT were not talking about turbos were talking about blowers.



1. duall charging is done with positive displacement blowers like an eaten or whipple, not with a centrifugal blower. A Centrifugal blower spools kinda like a turbo in that time is required for the turbine to create the pressure differential.

WrickM, I'm not so sure about this. It may be that it does to some extent, but it would'nt be as bad as a turbo's lag. A turbo just sort of free wheels along till the exhaust gases spin it enough to build boost. Where as if it were belt driven it could be rite on the edge of building boost at idle.

As far as a turbo being cheaper...I think that I could build something like this for under $400.

Stu

hey if you have access to super cheap parts then awesome. i just worked for a company that did some duall charging and so i shared what we found. the eaton and the turbo worked ok. it was just a matter of creating a manual valve for the eaton's bypass valve otherwise you were making it so inefficient it was blowing incredibly hot air into the engine. plus with two centrifugal type devices i can see the different flows being counter productive to one and other. Still i am not one to say don't try lol

on the price thing i just have always seen prochargers and vortec blowers a WAY overpriced and since the don't (or at least VERY rarely) come stock that makes them even more pricey.

 

[SparkandFire]

Sparkandfire is rite on the heat helping the turbo, otherwise you'd want to cool the exhaust instead of heat wrapping it. BUT were not talking about turbos were talking about blowers.



1. duall charging is done with positive displacement blowers like an eaten or whipple, not with a centrifugal blower. A Centrifugal blower spools kinda like a turbo in that time is required for the turbine to create the pressure differential.

WrickM, I'm not so sure about this. It may be that it does to some extent, but it would'nt be as bad as a turbo's lag. A turbo just sort of free wheels along till the exhaust gases spin it enough to build boost. Where as if it were belt driven it could be rite on the edge of building boost at idle.

As far as a turbo being cheaper...I think that I could build something like this for under $400.

Stu

You're right, positive displacement blowers (roots type) don't have the lag that a turbo or centrifugal blower has.

I was debating some type of engine driven compressor system that kicks in when you hit the brakes, charges an air tank, then when you take off from a stop, a valve backfeeds the air into the intake of the engine to give you off the line boost. a "Diesel Hybrid" type thing...

the only problem with a blower is that it robs power from the crank. Obviously, it adds more power than it takes by virtue of the fact that it increases the air mass and preheats it. The logic behind the "turbo vs. blower" debate was that the turbo basically uses "waste" energy to operate.

I think you would be better off with a twin turbo setup, a small A/R turbo to get going off the line, then a larger one for high end boost.

Or figure out a way to run air foil bearings in your turbo...

 

[WrickM]

You're right, positive displacement blowers (roots type) don't have the lag that a turbo or centrifugal blower has.

I was debating some type of engine driven compressor system that kicks in when you hit the brakes, charges an air tank, then when you take off from a stop, a valve backfeeds the air into the intake of the engine to give you off the line boost. a "Diesel Hybrid" type thing...

I've thought about the same thing but the air its self wouldn't be enough. you can't just have a stream of air blasting into the engine and get much extra. it would just displace the normal incoming air. (for the most part. i am sure you could get a little pressure to build, just not enough to justify the cost of the project). The thought i had was using the compressed air as work to drive a specially designed/modified turbo. i thought about a procharger too, but i think the gearing would create too much drag. so a compressor filling a fairly large tank while cruising, that at a specified throttle level releases that compressed air into a turbine of sorts that spins the turbo compressor and creates boost. it's just a lot of work for an experiment that likely won't work lol

 

[SparkandFire]

I've thought about the same thing but the air its self wouldn't be enough. you can't just have a stream of air blasting into the engine and get much extra. it would just displace the normal incoming air. (for the most part. i am sure you could get a little pressure to build, just not enough to justify the cost of the project). The thought i had was using the compressed air as work to drive a specially designed/modified turbo. i thought about a procharger too, but i think the gearing would create too much drag. so a compressor filling a fairly large tank while cruising, that at a specified throttle level releases that compressed air into a turbine of sorts that spins the turbo compressor and creates boost. it's just a lot of work for an experiment that likely won't work lol

Sounds like a lot of spinning parts...

I LIKE IT!

 

[towcat]

just a sidenote to really complicate things.....
I have a MBZ SL55 AMG in the shop right now and it has a Eaton blower added to the V8. The unique part is there is a electric clutch on the front of the blower to engage/disengage the unit. Holy mother of Christ does it make a difference when it engages I'm not sure how the system bypasses when it is not needed but when it does kick in and traction control is turned off....it's like the turbo in my GN lighting off for hyperdrive

 

[SparkandFire]

just a sidenote to really complicate things.....
I have a MBZ SL55 AMG in the shop right now and it has a Eaton blower added to the V8. The unique part is there is a electric clutch on the front of the blower to engage/disengage the unit. Holy mother of Christ does it make a difference when it engages I'm not sure how the system bypasses when it is not needed but when it does kick in and traction control is turned off....it's like the turbo in my GN lighting off for hyperdrive

That sounds like a pretty interesting concept really, I do wonder how they bypass the blower when it's not in use.

Did you "test" drive it to "test" the performance of the system??

 

[towcat]

Did you "test" drive it to "test" the performance of the system??

I tested the performance to see if it justified the extra $60k for the AMG package. All I gotta say is holey sheeeiiiittt.......
the same onramp I do in my truck is 60 mph. I did it in this monster at a buck thirty. Verified by my CHP buddy who was hot on my ass. got a stern warning.;p

 

[The Warden]

Gotta ask which ramp was this?