Twin Turbo Efficiency - a more efficient option?
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From: Outside Philly
Twin Turbo Efficiency - a more efficient option?
1. Lets assume that engine bay space is not a concern.
2. Lets also assume that the theory I propose does not require turbo placement to sacrific exhaust velocity. (Ideal exhaust headers for turbos are built to diameter and length specifications that will maximize exhaust speads before they enter the turbo, etc...)
Knows:
Intake inefficiency :
The G35 uses a single intake plenum. This system is not as efficient as a single cylinder to intake source system. A 1-to-1 system better allows for the maximum flow to each cylinder.
exhaust inefficiency:
The configuration of a V6 engine staggers the intake and exhaust charges. While there is a single intake plenum and two exhaust manifolds, 3 cylinders can intake a charge at a time, while each manifold does not expel the same amount of exhaust gasses at the same time. While one side is expeling two cylinders of exhaust gas at one moment, the other side is only expeling one cyinder of exhaust gas. There is, of course, a scavenger effect, but let's put that aside for the moment.
Theory: (perhaps not original, but just came to mind right now)
If you were able to configure the turbos, to recieve exhaust gases from the same pulse (2 from 1 side, 1 from the other), and route the resulting turbo intake charge to the oppositely charged intakes (keep in mind that I have already stated the assumptions above), would you have a more efficient turbo system that is currently offered for v6 engines?
2. Lets also assume that the theory I propose does not require turbo placement to sacrific exhaust velocity. (Ideal exhaust headers for turbos are built to diameter and length specifications that will maximize exhaust speads before they enter the turbo, etc...)
Knows:
Intake inefficiency :
The G35 uses a single intake plenum. This system is not as efficient as a single cylinder to intake source system. A 1-to-1 system better allows for the maximum flow to each cylinder.
exhaust inefficiency:
The configuration of a V6 engine staggers the intake and exhaust charges. While there is a single intake plenum and two exhaust manifolds, 3 cylinders can intake a charge at a time, while each manifold does not expel the same amount of exhaust gasses at the same time. While one side is expeling two cylinders of exhaust gas at one moment, the other side is only expeling one cyinder of exhaust gas. There is, of course, a scavenger effect, but let's put that aside for the moment.
Theory: (perhaps not original, but just came to mind right now)
If you were able to configure the turbos, to recieve exhaust gases from the same pulse (2 from 1 side, 1 from the other), and route the resulting turbo intake charge to the oppositely charged intakes (keep in mind that I have already stated the assumptions above), would you have a more efficient turbo system that is currently offered for v6 engines?
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From: Fort Rucker, AL
No because the length the pulses would have to travel would be unequal or too long if made equal. That is why merging the two compressor sides is the most common practice.
Originally Posted by f r e z N Y
Theory: (perhaps not original, but just came to mind right now)
If you were able to configure the turbos, to recieve exhaust gases from the same pulse (2 from 1 side, 1 from the other), and route the resulting turbo intake charge to the oppositely charged intakes (keep in mind that I have already stated the assumptions above), would you have a more efficient turbo system that is currently offered for v6 engines?
If you were able to configure the turbos, to recieve exhaust gases from the same pulse (2 from 1 side, 1 from the other), and route the resulting turbo intake charge to the oppositely charged intakes (keep in mind that I have already stated the assumptions above), would you have a more efficient turbo system that is currently offered for v6 engines?
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From: Outside Philly
Originally Posted by djniknala
No because the length the pulses would have to travel would be unequal or too long if made equal.
Thanks.
I just had a thought today while reading Corkey Bell's Maximum Boost; Designing, Testing and Installing Turbocharger Systems (thanks for the reference DaveO. On page 33, the author asserts that the radius of the discharge area of the gases into the turbine affect spool time and available boost. He states that a smaller discharge area causes the turbine to spool more quickly, but limits it's rotational speed in the upper rpms.
So... what about instead of a solid metal casing, you have some sort of mechanical metal casing that can constrict at low rpms, and gradually open at higher rpms? Hope this makes sense; I'm a noob.
So... what about instead of a solid metal casing, you have some sort of mechanical metal casing that can constrict at low rpms, and gradually open at higher rpms? Hope this makes sense; I'm a noob.
Originally Posted by f r e z N Y
1. Lets assume that engine bay space is not a concern.
2. Lets also assume that the theory I propose does not require turbo placement to sacrific exhaust velocity. (Ideal exhaust headers for turbos are built to diameter and length specifications that will maximize exhaust speads before they enter the turbo, etc...)
Knows:
Intake inefficiency :
The G35 uses a single intake plenum. This system is not as efficient as a single cylinder to intake source system. A 1-to-1 system better allows for the maximum flow to each cylinder.
exhaust inefficiency:
The configuration of a V6 engine staggers the intake and exhaust charges. While there is a single intake plenum and two exhaust manifolds, 3 cylinders can intake a charge at a time, while each manifold does not expel the same amount of exhaust gasses at the same time. While one side is expeling two cylinders of exhaust gas at one moment, the other side is only expeling one cyinder of exhaust gas. There is, of course, a scavenger effect, but let's put that aside for the moment.
Theory: (perhaps not original, but just came to mind right now)
If you were able to configure the turbos, to recieve exhaust gases from the same pulse (2 from 1 side, 1 from the other), and route the resulting turbo intake charge to the oppositely charged intakes (keep in mind that I have already stated the assumptions above), would you have a more efficient turbo system that is currently offered for v6 engines?
2. Lets also assume that the theory I propose does not require turbo placement to sacrific exhaust velocity. (Ideal exhaust headers for turbos are built to diameter and length specifications that will maximize exhaust speads before they enter the turbo, etc...)
Knows:
Intake inefficiency :
The G35 uses a single intake plenum. This system is not as efficient as a single cylinder to intake source system. A 1-to-1 system better allows for the maximum flow to each cylinder.
exhaust inefficiency:
The configuration of a V6 engine staggers the intake and exhaust charges. While there is a single intake plenum and two exhaust manifolds, 3 cylinders can intake a charge at a time, while each manifold does not expel the same amount of exhaust gasses at the same time. While one side is expeling two cylinders of exhaust gas at one moment, the other side is only expeling one cyinder of exhaust gas. There is, of course, a scavenger effect, but let's put that aside for the moment.
Theory: (perhaps not original, but just came to mind right now)
If you were able to configure the turbos, to recieve exhaust gases from the same pulse (2 from 1 side, 1 from the other), and route the resulting turbo intake charge to the oppositely charged intakes (keep in mind that I have already stated the assumptions above), would you have a more efficient turbo system that is currently offered for v6 engines?
Let's see, the VQ35DE is designed with 6 cylinders in a V configuration. Bank 1 (passinger's side) cylinders are 1, 3 & 5 with Bank 2's being 2, 4 & 6. The firing order is 1 - 2 - 3 - 4 - 5 - 6. The VQ is a four cycle engine... suck - squeeze - bang - blow. The 6 cylinders provide front to rear, bank to bank "puts", and then there's the cam timing, overlap & duration, reversion... now I'm really confused!
Last edited by DaveO; Sep 15, 2005 at 05:25 PM.
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