Despite the other posts, a 2.3 Gen 2 is more efficient than a TVS. A twin-screw is more efficient than a roots blower. The 4 lobe 160degree twist TVS is certainly a lot more efficient than the stock Eaton, but still not as efficient as a twin screw.
Eaton TVS powered 03 Cobra runs 10s
- Thread starter Senkak
- Start date
Despite the other posts, a 2.3 Gen 2 is more efficient than a TVS. A twin-screw is more efficient than a roots blower. The 4 lobe 160degree twist TVS is certainly a lot more efficient than the stock Eaton, but still not as efficient as a twin screw.
Which blower are you talking about when you say a 2.3 Gen 2?
Whipple.
OEM's pick Eaton units for just that reason. However, lots of guys have had twinscrews on their cars for many years and thousands and thousands of miles and I don't see too much in the way of failures :shrug:
very good question maybe steggy or posi can chime in
For a low mile project vehicle anything will do. Mercedes Benz discontinued Lysholm blowers on all their AMG cars due to excessive costs of warranty claims. All twin screws have been discontinued by OEM's including all luxury brands.
I have 450K on an Eaton on one of my cars. 100% original with pulley change and fluid change every 100K. Still pushes 15psi all day long with zero bearing noises.
Here's a write-up that Charles at magnum/Torque tech did a while back.
Although Screw is known and associated to bigger power increases, that doesn't always mean it's better. For instance some people don't know it, but they're running their Screw S/C's out side the MFG acceptable tolerances, "AND WRRNTY"
As said the diff is more related to larger displacement, (which is a must with a screw due to it's design). That doesn't mean you cant make a 112 cu in Roots kick ass.
If you'd really like to read some extremly technical diff between the two, I just did a story on it HERE
A few quotes from it.
Although the mathematics becomes involved the result is the screw rotor requires about a 17% larger unit volume to displace the same volume of air compared to a roots rotor of equal airflow capacity.
A very good article comparing a screw supercharger to a three-cycle Eaton supercharger was published in the June 2002 issue of Muscle Mustang and Fast Ford. In this article the test results comparing a screw supercharger at 9-psi boost to a stock Eaton M112 also at 9-psi boost was documented, the screw supercharger made 16 more hp under these conditions. Although significant these hp gains are not that impressive. It should also be pointed out that heat is generated within the twin-screw compressor because air is compressed within the supercharger causing the supercharger to become hot unless provisions are made to cool it.
All screw compressors are of an asymmetrical design having male and female rotors with the male having fewer lobes then the female. One popular screw supercharger has a 4/6-rotor configuration. The male rotor has 4 large lobes mating to the female rotor that has 6 large cavities or channels. Most of the air flows through the large channels of the female rotor since the channels in the male rotor are very narrow and have little volume. Since the male and female rotors are meshed they must turn in unison therefore the male rotor with only 4 lobes must turn 1.5 times for every turn of the female rotor having 6 cavities. For instance if the female is turning 18,000 rpm the male rotor must turn 27,000 rpm to keep up. The supercharger’s drive pulley is typically connected to the female rotor so the male rotor is turning 150% faster then the drive pulley in this example. Some screw supercharger providers limit their warrantee to 18,000-rpm pulley speed. Another Twin Screw supercharger manufacture has a 3/5-rotor configuration. This supercharger in order for the rotors to mesh properly has a 3 to 5 internal gear ratio therefore at a pulley speed of 18,000 rpm the male rotor must turn 30,000 rpm to keep up.
"The Little Supercharger That Could"
Last month the Magnum Powers Supercharger was picked as the Mod of the Month here in the e-zine, we showed examples of the awesome results on various Lightning's, a video, dyno results, and talked a little about the Product itself. What we didn't even begin to talk about, was just how much Supercharger you get, and what a great value it is. Magnum Powers is clearly the leader in performance, quality, and price.
What do you look for in a performance modification? I know I look for value, reliability, and more power. The Magnum Powers not only gives you that instant bolt on Power, but it also gives you a stronger "more reliable Supercharger". It has a stronger front shaft and snout assembly, and an improved design that will perform at optimal performance all the way up to 2400 RPM, (thats about twice the RPM in which the stock Eatons can perform). This also means if you spin it hard and fast, (like it's designed to be used), you can boost your Beast right into the 10's, and put down 600+ HP, giving you great value to go along with a great looking Supercharger. I see it as, "The Little Supercharger That Could"
We currently have two choices of aftermarket Supercharges to pick from, each are different in design, and actually two very different types of Superchargers. To understand more I thought we'd let the Magnum Man himself, "Charles Warner", explain the difference between the Roots and Screw Supercharger, as well as the advantages and disadvantages of both. You'll see that Charles was very unbiased with his comparisons, and does not distort the facts for either side. After all when your's is half the price, "and very capable of getting the job done", you have nothing to hide. This article is very technical, but to understand the differences it needs to be.
A Roots Supercharger versus Twin-Screw Compressor Comparison
By: Charles Warner
For: Magnum Powers, LLC
*
Introduction:
Everyone knows…
Screw Superchargers are true compressors whereas Roots Superchargers are simple blowers therefore Screw compressors having greater adiabatic efficiency are better superchargers then Roots.
At least that’s the part of the story that most people have heard. But, that’s not the whole story at all. Like any complex, high performance mechanical system, a supercharger must be evaluated as part of the engine’s overall operating environment.
*Background:
In order to evaluate which type supercharger is best we must first understand some of the fundamentals associated with twin-screw compressors and roots type blowers. First there are millions of twin-screw compressors used throughout the world for refrigerant compressors in large industrial buildings, shopping centers, etc and for good reason, they are very efficient as high-pressure compressors where the working pressure remains nearly constant. It is not uncommon for refrigerant and air compressors to have working pressures of 175 psi or more. In these applications screw compressors are nearly unbeatable. It should be noted screw compressors in these applications tend to be slow turning large machines.
Screw compressors have three cycles: intake, compression and exit, while a true roots blower has only two, intake and exit. It is clear screw compressors are performing more functions then the roots. In life there is rarely a “free lunch” so what is the cost and what is given up in the pursuit of adiabatic efficiency [1] and the added compression cycle found in the screw compressor design?
[1] Adiabatic Efficiency is the ratio of heat entering or leaving a system. If a compression cycle occurs without additional heat entering the system it is considered to be 100% adiabatic efficient. If on the other hand additional heat enters the system (through friction or other sources) that is equal to the energy required to compress the air the system is considered 50% adiabatic efficient.
*Internal Compression Ratio:
Screw Compressors have an “Internal Compression Ratio”. The compression ratio is designed into the machine by the careful placement of the intake and exit ports as well as the wrap angle (helix) of the screws. As with the internal combustion engine the compression ratio of a screw compressor is fixed by design. The formula for calculating the proper compression ratio to use is: Cr = (Exit Pressure + Intake Pressure) / Intake Pressure. A screw compressor designed for an intake pressure of 15 psi and an exit pressure of 165 psi would have a compression ratio of about 12 to 1 for example. A compressor of this design would have maximum efficiency when the exit pressure is 165 psi and its efficiency would drop off on either side of that pressure.*
Screw Rotor Configurations:
All screw compressors are of an asymmetrical design having male and female rotors with the male having fewer lobes then the female. One popular screw supercharger has a 4/6-rotor configuration. The male rotor has 4 large lobes mating to the female rotor that has 6 large cavities or channels. Most of the air flows through the large channels of the female rotor since the channels in the male rotor are very narrow and have little volume. Since the male and female rotors are meshed they must turn in unison therefore the male rotor with only 4 lobes must turn 1.5 times for every turn of the female rotor having 6 cavities. For instance if the female is turning 18,000 rpm the male rotor must turn 27,000 rpm to keep up. The supercharger’s drive pulley is typically connected to the female rotor so the male rotor is turning 150% faster then the drive pulley in this example. Some screw supercharger providers limit their warrantee to 18,000-rpm pulley speed. Another Twin Screw supercharger manufacture has a 3/5-rotor configuration. This supercharger in order for the rotors to mesh properly has a 3 to 5 internal gear ratio therefore at a pulley speed of 18,000 rpm the male rotor must turn 30,000 rpm to keep up.
*Screw Compressors used as Superchargers:
Now consider screw compressors used as automotive superchargers. The first question a designer must answer is what compression ratio should the supercharger be designed for? To answer that question we must first review the working pressures seen in the system so a proper determination can be made. Unlike the nearly constant pressures seen in refrigerant compressors the operating pressures in an automotive application vary over a very large range from high vacuum at idle or cruise conditions all the way to full boost that can very from 7 psi to 25 psi or more. A casual observer might think a screw compressor’s “internal compression ratio” is designed to maximize efficiency at maximum boost pressure because at maximum boost is where maximum benefit from the screw compressor’s adiabatic efficiency is desired. A screw compressor designed for maximum efficiency at 25 psi boost would have a compression ratio of 2.7 to 1, the equation being Cr = (14.7 + 25) / 14.7. Although this answer would be great for a car that is rolled off a trailer, makes a pass down the ¼ mile and put back on the trailer for a ride back to the garage, it is not a good answer for the everyday hotrod that is driven on the street because the compressor is compressing to its internal compression ratio all the time, at idle, while cruising down the highway or putting around town, wasting gas and creating heat. Remember, air in a screw compressor is compressed internally inside the supercharger so it is happening all the time, even when it is not needed. All it does is waste the energy used by the constantly compressing compressor when the manifold pressure is below the fixed internal compression ratio. The typical bypass valve seen on many superchargers does nothing to eliminate the internal compression happening inside the screw compressor. A very popular and successful screw supercharger provider chose a compression ratio of 1.4 to 1 that has maximum efficiency at about 7 psi boost. The selection of 1.4 to 1 appears to be a very good compromise between practical requirements and performance and is ideal for low boost applications. However as the manifold pressure (actual boost pressure) begins to exceed the design boost pressure, the effect of the decreasing volume within the compressor starts to diminish. For instance about half the potential benefit of a screw supercharger when operating at 14 psi boost is lost if its internal compression ratio is 1.4 to 1 and at 21 psi boost about 2/3’s of the potential benefit is not realized. A very good article comparing a screw supercharger to a three-cycle Eaton supercharger was published in the June 2002 issue of Muscle Mustang and Fast Ford. In this article the test results comparing a screw supercharger at 9-psi boost to a stock Eaton M112 also at 9-psi boost was documented, the screw supercharger made 16 more hp under these conditions. Although significant these hp gains are not that impressive. It should also be pointed out that heat is generated within the twin-screw compressor because air is compressed within the supercharger causing the supercharger to become hot unless provisions are made to cool it. So what is given up and what are the costs associated with this quest for improved, but narrowly limited adiabatic efficiency? To answer that question we must first understand a few more fundamentals of twin-screw and roots rotors.
Many years of research and design has been devoted to the perfection of the roots rotor profile to minimize parasitic losses and maximize displacement per unit volume. Since the screw rotor must also create a volume within the rotor profile that reduces in volume as the rotor turns displacement per unit volume was sacrificed in order to provide this extra function. In the industry, the parameter that describes displacement per unit volume is “cross-sectional area coefficient” (CSAC), defined as the ratio of the flow area (cavity area) between the lobes to the male rotor’s diameter squared. In the case of roots the CSAC is .95 and for the 4/6 screw it is .50. Although the mathematics becomes involved the result is the screw rotor requires about a 17% larger unit volume to displace the same volume of air compared to a roots rotor of equal airflow capacity.**
Roots rotors have 3 lobes on both rotors; this requires both rotors to be driven at the same speed. As mentioned above the male rotor of a 4/6-screw design is driven 150% faster then the female and the male rotor of the 3/5-screw design must turn 167% faster. Because the female rotor has large cavities and moves most of the air the male rotor has large lobes made of metal that mesh with the female cavities. This design requires the male rotor to be massive and also requires the male rotor to turn faster then the female thus limiting operating speed of the air moving female rotor. Although this feature is not a limitation for large slow turning highly efficient refrigerant compressors it does become an issue to consider when designing compact, high-speed superchargers intended for the confines of today’s cramped engine compartments.
*
Summary:
Both Roots and Screw rotors have their advantages and disadvantages as outlined above. Although the Screw compressor has a theoretical adiabatic efficiency advantage, that advantage is not fully realized in high boost applications because of practical requirements of fuel economy and heat generation within the supercharger. A disadvantage of the screw type supercharger is the fact the male rotor is massive and must turn faster then the female and therefore limits operating speed and results in greater size for a given airflow rating. On the other hand the roots has the size advantage and can be spun faster moving more air then a screw compressor of the same physical size.
*
Roots benefits:
Less heat builds up in the supercharger since air is not compressed internally thus requiring less time to cool down between ¼ track runs.
The Roots is a small compact high-speed design resulting in less bulk in engine compartment. Smaller heat load on the intercooler system under low boost conditions and better fuel economy. The Roots is much less expensive to manufacture.
*
Screw benefits:
Better all-out performance if the fixed internal compression ratio matches the boost pressure.*
The bottom line is numerous dyno and track tests have demonstrated Magnum Powers’ 1.8 liter two-cycle 24,000 rpm Roots blower compares well in power and ¼ mile track times with a much larger 2.2 liter twin-screw compressor and at significantly lower cost. And now you know the rest of the story.
Although Screw is known and associated to bigger power increases, that doesn't always mean it's better. For instance some people don't know it, but they're running their Screw S/C's out side the MFG acceptable tolerances, "AND WRRNTY"
As said the diff is more related to larger displacement, (which is a must with a screw due to it's design). That doesn't mean you cant make a 112 cu in Roots kick ass.
If you'd really like to read some extremly technical diff between the two, I just did a story on it HERE
A few quotes from it.
Although the mathematics becomes involved the result is the screw rotor requires about a 17% larger unit volume to displace the same volume of air compared to a roots rotor of equal airflow capacity.
A very good article comparing a screw supercharger to a three-cycle Eaton supercharger was published in the June 2002 issue of Muscle Mustang and Fast Ford. In this article the test results comparing a screw supercharger at 9-psi boost to a stock Eaton M112 also at 9-psi boost was documented, the screw supercharger made 16 more hp under these conditions. Although significant these hp gains are not that impressive. It should also be pointed out that heat is generated within the twin-screw compressor because air is compressed within the supercharger causing the supercharger to become hot unless provisions are made to cool it.
All screw compressors are of an asymmetrical design having male and female rotors with the male having fewer lobes then the female. One popular screw supercharger has a 4/6-rotor configuration. The male rotor has 4 large lobes mating to the female rotor that has 6 large cavities or channels. Most of the air flows through the large channels of the female rotor since the channels in the male rotor are very narrow and have little volume. Since the male and female rotors are meshed they must turn in unison therefore the male rotor with only 4 lobes must turn 1.5 times for every turn of the female rotor having 6 cavities. For instance if the female is turning 18,000 rpm the male rotor must turn 27,000 rpm to keep up. The supercharger’s drive pulley is typically connected to the female rotor so the male rotor is turning 150% faster then the drive pulley in this example. Some screw supercharger providers limit their warrantee to 18,000-rpm pulley speed. Another Twin Screw supercharger manufacture has a 3/5-rotor configuration. This supercharger in order for the rotors to mesh properly has a 3 to 5 internal gear ratio therefore at a pulley speed of 18,000 rpm the male rotor must turn 30,000 rpm to keep up.
"The Little Supercharger That Could"
Last month the Magnum Powers Supercharger was picked as the Mod of the Month here in the e-zine, we showed examples of the awesome results on various Lightning's, a video, dyno results, and talked a little about the Product itself. What we didn't even begin to talk about, was just how much Supercharger you get, and what a great value it is. Magnum Powers is clearly the leader in performance, quality, and price.
What do you look for in a performance modification? I know I look for value, reliability, and more power. The Magnum Powers not only gives you that instant bolt on Power, but it also gives you a stronger "more reliable Supercharger". It has a stronger front shaft and snout assembly, and an improved design that will perform at optimal performance all the way up to 2400 RPM, (thats about twice the RPM in which the stock Eatons can perform). This also means if you spin it hard and fast, (like it's designed to be used), you can boost your Beast right into the 10's, and put down 600+ HP, giving you great value to go along with a great looking Supercharger. I see it as, "The Little Supercharger That Could"
We currently have two choices of aftermarket Supercharges to pick from, each are different in design, and actually two very different types of Superchargers. To understand more I thought we'd let the Magnum Man himself, "Charles Warner", explain the difference between the Roots and Screw Supercharger, as well as the advantages and disadvantages of both. You'll see that Charles was very unbiased with his comparisons, and does not distort the facts for either side. After all when your's is half the price, "and very capable of getting the job done", you have nothing to hide. This article is very technical, but to understand the differences it needs to be.
A Roots Supercharger versus Twin-Screw Compressor Comparison
By: Charles Warner
For: Magnum Powers, LLC
*
Introduction:
Everyone knows…
Screw Superchargers are true compressors whereas Roots Superchargers are simple blowers therefore Screw compressors having greater adiabatic efficiency are better superchargers then Roots.
At least that’s the part of the story that most people have heard. But, that’s not the whole story at all. Like any complex, high performance mechanical system, a supercharger must be evaluated as part of the engine’s overall operating environment.
*Background:
In order to evaluate which type supercharger is best we must first understand some of the fundamentals associated with twin-screw compressors and roots type blowers. First there are millions of twin-screw compressors used throughout the world for refrigerant compressors in large industrial buildings, shopping centers, etc and for good reason, they are very efficient as high-pressure compressors where the working pressure remains nearly constant. It is not uncommon for refrigerant and air compressors to have working pressures of 175 psi or more. In these applications screw compressors are nearly unbeatable. It should be noted screw compressors in these applications tend to be slow turning large machines.
Screw compressors have three cycles: intake, compression and exit, while a true roots blower has only two, intake and exit. It is clear screw compressors are performing more functions then the roots. In life there is rarely a “free lunch” so what is the cost and what is given up in the pursuit of adiabatic efficiency [1] and the added compression cycle found in the screw compressor design?
[1] Adiabatic Efficiency is the ratio of heat entering or leaving a system. If a compression cycle occurs without additional heat entering the system it is considered to be 100% adiabatic efficient. If on the other hand additional heat enters the system (through friction or other sources) that is equal to the energy required to compress the air the system is considered 50% adiabatic efficient.
*Internal Compression Ratio:
Screw Compressors have an “Internal Compression Ratio”. The compression ratio is designed into the machine by the careful placement of the intake and exit ports as well as the wrap angle (helix) of the screws. As with the internal combustion engine the compression ratio of a screw compressor is fixed by design. The formula for calculating the proper compression ratio to use is: Cr = (Exit Pressure + Intake Pressure) / Intake Pressure. A screw compressor designed for an intake pressure of 15 psi and an exit pressure of 165 psi would have a compression ratio of about 12 to 1 for example. A compressor of this design would have maximum efficiency when the exit pressure is 165 psi and its efficiency would drop off on either side of that pressure.*
Screw Rotor Configurations:
All screw compressors are of an asymmetrical design having male and female rotors with the male having fewer lobes then the female. One popular screw supercharger has a 4/6-rotor configuration. The male rotor has 4 large lobes mating to the female rotor that has 6 large cavities or channels. Most of the air flows through the large channels of the female rotor since the channels in the male rotor are very narrow and have little volume. Since the male and female rotors are meshed they must turn in unison therefore the male rotor with only 4 lobes must turn 1.5 times for every turn of the female rotor having 6 cavities. For instance if the female is turning 18,000 rpm the male rotor must turn 27,000 rpm to keep up. The supercharger’s drive pulley is typically connected to the female rotor so the male rotor is turning 150% faster then the drive pulley in this example. Some screw supercharger providers limit their warrantee to 18,000-rpm pulley speed. Another Twin Screw supercharger manufacture has a 3/5-rotor configuration. This supercharger in order for the rotors to mesh properly has a 3 to 5 internal gear ratio therefore at a pulley speed of 18,000 rpm the male rotor must turn 30,000 rpm to keep up.
*Screw Compressors used as Superchargers:
Now consider screw compressors used as automotive superchargers. The first question a designer must answer is what compression ratio should the supercharger be designed for? To answer that question we must first review the working pressures seen in the system so a proper determination can be made. Unlike the nearly constant pressures seen in refrigerant compressors the operating pressures in an automotive application vary over a very large range from high vacuum at idle or cruise conditions all the way to full boost that can very from 7 psi to 25 psi or more. A casual observer might think a screw compressor’s “internal compression ratio” is designed to maximize efficiency at maximum boost pressure because at maximum boost is where maximum benefit from the screw compressor’s adiabatic efficiency is desired. A screw compressor designed for maximum efficiency at 25 psi boost would have a compression ratio of 2.7 to 1, the equation being Cr = (14.7 + 25) / 14.7. Although this answer would be great for a car that is rolled off a trailer, makes a pass down the ¼ mile and put back on the trailer for a ride back to the garage, it is not a good answer for the everyday hotrod that is driven on the street because the compressor is compressing to its internal compression ratio all the time, at idle, while cruising down the highway or putting around town, wasting gas and creating heat. Remember, air in a screw compressor is compressed internally inside the supercharger so it is happening all the time, even when it is not needed. All it does is waste the energy used by the constantly compressing compressor when the manifold pressure is below the fixed internal compression ratio. The typical bypass valve seen on many superchargers does nothing to eliminate the internal compression happening inside the screw compressor. A very popular and successful screw supercharger provider chose a compression ratio of 1.4 to 1 that has maximum efficiency at about 7 psi boost. The selection of 1.4 to 1 appears to be a very good compromise between practical requirements and performance and is ideal for low boost applications. However as the manifold pressure (actual boost pressure) begins to exceed the design boost pressure, the effect of the decreasing volume within the compressor starts to diminish. For instance about half the potential benefit of a screw supercharger when operating at 14 psi boost is lost if its internal compression ratio is 1.4 to 1 and at 21 psi boost about 2/3’s of the potential benefit is not realized. A very good article comparing a screw supercharger to a three-cycle Eaton supercharger was published in the June 2002 issue of Muscle Mustang and Fast Ford. In this article the test results comparing a screw supercharger at 9-psi boost to a stock Eaton M112 also at 9-psi boost was documented, the screw supercharger made 16 more hp under these conditions. Although significant these hp gains are not that impressive. It should also be pointed out that heat is generated within the twin-screw compressor because air is compressed within the supercharger causing the supercharger to become hot unless provisions are made to cool it. So what is given up and what are the costs associated with this quest for improved, but narrowly limited adiabatic efficiency? To answer that question we must first understand a few more fundamentals of twin-screw and roots rotors.
Many years of research and design has been devoted to the perfection of the roots rotor profile to minimize parasitic losses and maximize displacement per unit volume. Since the screw rotor must also create a volume within the rotor profile that reduces in volume as the rotor turns displacement per unit volume was sacrificed in order to provide this extra function. In the industry, the parameter that describes displacement per unit volume is “cross-sectional area coefficient” (CSAC), defined as the ratio of the flow area (cavity area) between the lobes to the male rotor’s diameter squared. In the case of roots the CSAC is .95 and for the 4/6 screw it is .50. Although the mathematics becomes involved the result is the screw rotor requires about a 17% larger unit volume to displace the same volume of air compared to a roots rotor of equal airflow capacity.**
Roots rotors have 3 lobes on both rotors; this requires both rotors to be driven at the same speed. As mentioned above the male rotor of a 4/6-screw design is driven 150% faster then the female and the male rotor of the 3/5-screw design must turn 167% faster. Because the female rotor has large cavities and moves most of the air the male rotor has large lobes made of metal that mesh with the female cavities. This design requires the male rotor to be massive and also requires the male rotor to turn faster then the female thus limiting operating speed of the air moving female rotor. Although this feature is not a limitation for large slow turning highly efficient refrigerant compressors it does become an issue to consider when designing compact, high-speed superchargers intended for the confines of today’s cramped engine compartments.
*
Summary:
Both Roots and Screw rotors have their advantages and disadvantages as outlined above. Although the Screw compressor has a theoretical adiabatic efficiency advantage, that advantage is not fully realized in high boost applications because of practical requirements of fuel economy and heat generation within the supercharger. A disadvantage of the screw type supercharger is the fact the male rotor is massive and must turn faster then the female and therefore limits operating speed and results in greater size for a given airflow rating. On the other hand the roots has the size advantage and can be spun faster moving more air then a screw compressor of the same physical size.
*
Roots benefits:
Less heat builds up in the supercharger since air is not compressed internally thus requiring less time to cool down between ¼ track runs.
The Roots is a small compact high-speed design resulting in less bulk in engine compartment. Smaller heat load on the intercooler system under low boost conditions and better fuel economy. The Roots is much less expensive to manufacture.
*
Screw benefits:
Better all-out performance if the fixed internal compression ratio matches the boost pressure.*
The bottom line is numerous dyno and track tests have demonstrated Magnum Powers’ 1.8 liter two-cycle 24,000 rpm Roots blower compares well in power and ¼ mile track times with a much larger 2.2 liter twin-screw compressor and at significantly lower cost. And now you know the rest of the story.
Keep in mind no one has even seen a completed production model of the VMP TVS 2.3 except for the 2 prototypes that have been on my car
As far as we know I have the only 03-04 TVS 2.3 powered Cobra.
The unit will not require any porting.
It is being designed for maximum efficient air flow.
The inlet will be as large as possible while still being a bolt on upgrade.
We really appreciate all of the support and patience we have received during this long process.
RedFox
I appreciate you posting the article.
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Everything I've seen points to Twin Screws producing lower downstream air temps over a similarly boosted Roots blower.
:shrug:
That information was written by Charles at Magnum. it really depends on the parameters of the test. The twin screw tests that I've seen use an Eaton spun way beyond design parameters to use for their comparisons. If you compress air internally, you will produce more heat.
Run a blower on a road course in 30 minute sessions and do a comparison against another similar car with all things being equal. Otherwise, all you have is a sales pitch set-up in conditions that favour the salesman.
Correct.
Where's temperature on this graph?
It doesn't matter. All things being equal in the real world a twin screw will make more power than a roots because it's more efficient. In certain situations the power difference may not be that much, but in the end the twin screw is simply more efficient.
Correct.
Finally. Something that shows CFM instead of PSI. CFM is what matters in forced induction.
You claim lower temps and efficiency, yet you have no supporting evidence to support your statements. My point is that the twin screw vendors make statements which may have been true with previous generations blowers but I have yet to see a proper comparison with the TVS.
Porshe and Audi chose the TVS due to the lowest parasitic loss in the industry which is a measure of efficiency. GM chose the TVS for the ZR1 due (in their words) " near turbo efficiency. The ZR1 was initially specified to be turbo but GM engineers after testing picked the TVS. In these high end applications, the small difference with the twin screw was not even a consideration.
No. OEM's choose TVS blowers because they're cheaper and more durable.
Same displacement, same boost, a twin screw will make more power than a roots. I think the TVS is a great blower and for most people will make very similar power to a twin screw, but in the end if you're absolutely going for it, a twin screw will make more power.
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Agreed. Eaton is also a HUGE OE supplier. They don't need to worry about a vendor killing manufacturing schedule.
Click the link below for upated inforamtion.
This project is just about to come to fruition!!!
http://www.svtperformance.com/forums/engine-tuning-214/789264-vmp-2-3l-tvs-terminator-pics.html
This project is just about to come to fruition!!!
http://www.svtperformance.com/forums/engine-tuning-214/789264-vmp-2-3l-tvs-terminator-pics.html
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