[ron scubadiver]

Does any car manufacturer use a centrifugal supercharger?

Just looking at the two types it seems a centri costs less and takes less time to install although there may be a lag issue due to the length of the intercooler plumbing.

[80sMetalDude]

https://www.procharger.com/centrifugal-supercharger

[Cdflyer]

No manufacturer uses a centrifugal charger. But, they have proven time and time again to be reliable and top performers in the aftermarket. I've never seen a FAST PD blower car where it doesn't stick through the hood with a bug catcher. On the other hand, there are dozens of FAST cars with a Centrifugal mounted low and up front with a crank drive.

For this discussion, we'll assume you're inquiring about a 6th gen. In which case it's strictly a matter of choice. All option right now can produce more then enough power for a 9 second time slip. The PD's will heat soak a bit more then the centrifugal, but most people would be pressed to notice the difference.

[ron scubadiver]

Originally Posted by Cdflyer

No manufacturer uses a centrifugal charger. But, they have proven time and time again to be reliable and top performers in the aftermarket.

Thanks for the answer. Aftermarket superchargers sell in relatively small numbers. Even smaller numbers if the car is not common like a V8 M3. It appears to be easier to adapt a centrifugal blower to a given application since a new intake manifold is not needed and there are no hood clearance issues.

I continue to wonder why car manufacturers prefer PD blowers. My most likely guess is fuel efficiency as that dominates many engineering decisions these days.

[1le32907]

My take is they don't wanna build boost they want to have the car to have instant boost the moment you get the gas. A centri is probably less on gas but pd blower will maintain the same boost level. Just my .02

[ProCharger]

Originally Posted by ron scubadiver

Just looking at the two types it seems a centri costs less and takes less time to install although there may be a lag issue due to the length of the intercooler plumbing.

No lag what so ever...

Hence why I use the hashtag #TheAntiLag on the FB and Instagram

Originally Posted by Cdflyer

No manufacturer uses a centrifugal charger. But, they have proven time and time again to be reliable and top performers in the aftermarket.

Kawasaki uses one on their wicked high HP sport bike.
Others have used them in the past, and well the old "War Bird" up in the skies all used them on the big radial engines.

Originally Posted by ron scubadiver

I continue to wonder why car manufacturers prefer PD blowers. My most likely guess is fuel efficiency as that dominates many engineering decisions these days.

Packaging, Costs, Company ties to OEM's, patents, the list goes on.

But, it's cool we still love bolting them ours on and making KILLER street terrors and track monsters. ...or in the case of the Corvette Z06, unbolting their blower, and putting ours on.

[ProCharger]

Originally Posted by 1le32907

My take is they don't wanna build boost they want to have the car to have instant boost the moment you get the gas. A centri is probably less on gas but pd blower will maintain the same boost level. Just my .02

The average user things "if it peels out, its fast"
The words "heat soak", "power fade", etc. aren't even in their heads.

Most don't care what it does in the 0-60, 1/8th mile, or 1/4 mile.
Because maybe once in a while they "spin the tires" leaving the stop light after getting something from Home Depot.

Guess what we always try to prove is that Dyno sheets aren't always everything, and track performance is the real test. Easy installation for the DIY guy, and price point. Those are our real strengths, and always will be.

[toohighpsi]

OEM's look at the following items when making a decision for their FI needs (super or turbo):

1. Quality (reliability)
2. Efficiency (performance)
3. Cost

First off is the durability of the device, it needs to be as maintenance free as possible and capable of surviving the OEM's testing requirements with no degradation of performance over that test period. Testing in this area consists of hundreds of hours of operation at or near the peak requirements of the boosting device. While this is the entry condition to even be considered for these applications, efficiency plays into this role also when controlling thermal conditions for long life.

Next is efficiency - specifically "Compressor Efficiency" which is all encompassing of the boosting device and is the measurement that is used when making comparisons between options. This should NOT be confused with "Adiabatic" or Thermal" efficiency - which is the information that you will normally find posted for SC and TC devices out there.

So what is the difference?

Adiabatic or Thermal Efficiency (%) is the comparison between the IDEAL air temperature rise during the compression process and the ACTUAL air temperature rise during the compression process. It provides information on the compressor only related to the compression process - no information relating the mechanical efficiency of the compressor is included.

Compressor Efficiency (%) is the comparison between the IDEAL power required for a specific mass flow and pressure ratio and the ACTUAL power required for a specific mass flow and pressure ratio. It encompasses all aspects of the compressor - thermal and mechanical efficiency.

When you start looking at mechanical efficiency, speed is not your friend, we all know the equation right? HP = Torque * RPM / 5252. All of the friction mechanical losses in any SC are pretty much the same amount of torque, we have bearings, gears, windage from oil, and seals. While lots of advancements exist and are applied to these components whenever possible, we can see one impact from the equation that could separate very similar components is the speed. As SC impeller speed increases, the HP requirements for frictional losses increase - which in turn decreases your Compressor Efficiency.

In the OEM world, most companies use an Eaton (or Eaton based) device. On these SC's, Adiabatic Efficiency and Compressor Efficiency are very close to each other indicating a very high mechanical efficiency (along with good thermal efficiency).

For example, the TVS R1900 used on the CTSV has a peak adiabatic (thermal) efficiency of about 72% and peak Compressor Efficiency of about 69% - essentially losing only a small percent of its drive power to mechanical losses.

On the other hand, if we want to look at a worse case scenario, we'd consider a "friction drive" centrifugal supercharger. In this case we're relying on the friction (bad word already) of rollers or balls to provide the step-up ratio from our input pulley to drive our centrifugal impeller wheel to speed of 60,000 RPM - 80,000 RPM - along with seals and bearings (at least 1 seal and 2 bearings) at that same high speed. This type of device will have an adiabatic efficiency of about 72% and a Compressor Efficiency of about 31%. So, at least half of the input power put into the belt for this device is consumed by the drive system to get the compressor wheel up to the speed and compress the air.

Just because a device has low Compressor Efficiency dosen't mean that it can't make a lot of power, it just means that it will consume more power when doing it. Top Fuelers are a great example of this, while they have a SC that probably has less than 45%-50% Compressor Efficiency, they still make thousands of HP because they have the capability of moving huge amounts of air. You need to move enough air to make the power you are desiring, but the SC with the highest Compressor Efficiency will make the most power (with all else - intercooler, throttlebody, etc being the same).

Now I've pretty much provided you with the best and worst examples that exist in the SC market today, everything else out there falls somewhere between these two examples. If you're an OEM, you have access to this data - most OEMs have test stands to acquire this data themselves or have contracted test facilities that can perform the tests for comparison purposes.

Finally there is cost which is a tough one, but you have to hit the other hurdles to get to this point. Turbochargers are the big competition in this area, turbocharger device cost is cheap, but installation cost is not.

[ron scubadiver]

Sounds to me fuel efficiency is somewhat better with a PD. In this over regulated world that might explain car manufacturer preference. The Kawasaki bike at least does provide an example of manufacturer using a centri.

Obviously, turbocharger installation by OEM's is not costly, especially when pricing a turbo 4 against an NA 6.

[Atomic Ed]

Originally Posted by toohighpsi

OEM's look at the following items when making a decision for their FI needs (super or turbo):

1. Quality (reliability)
2. Efficiency (performance)
3. Cost

First off is the durability of the device, it needs to be as maintenance free as possible and capable of surviving the OEM's testing requirements with no degradation of performance over that test period. Testing in this area consists of hundreds of hours of operation at or near the peak requirements of the boosting device. While this is the entry condition to even be considered for these applications, efficiency plays into this role also when controlling thermal conditions for long life.

Next is efficiency - specifically "Compressor Efficiency" which is all encompassing of the boosting device and is the measurement that is used when making comparisons between options. This should NOT be confused with "Adiabatic" or Thermal" efficiency - which is the information that you will normally find posted for SC and TC devices out there.

So what is the difference?

Adiabatic or Thermal Efficiency (%) is the comparison between the IDEAL air temperature rise during the compression process and the ACTUAL air temperature rise during the compression process. It provides information on the compressor only related to the compression process - no information relating the mechanical efficiency of the compressor is included.

Compressor Efficiency (%) is the comparison between the IDEAL power required for a specific mass flow and pressure ratio and the ACTUAL power required for a specific mass flow and pressure ratio. It encompasses all aspects of the compressor - thermal and mechanical efficiency.

When you start looking at mechanical efficiency, speed is not your friend, we all know the equation right? HP = Torque * RPM / 5252. All of the friction mechanical losses in any SC are pretty much the same amount of torque, we have bearings, gears, windage from oil, and seals. While lots of advancements exist and are applied to these components whenever possible, we can see one impact from the equation that could separate very similar components is the speed. As SC impeller speed increases, the HP requirements for frictional losses increase - which in turn decreases your Compressor Efficiency.

In the OEM world, most companies use an Eaton (or Eaton based) device. On these SC's, Adiabatic Efficiency and Compressor Efficiency are very close to each other indicating a very high mechanical efficiency (along with good thermal efficiency).

For example, the TVS R1900 used on the CTSV has a peak adiabatic (thermal) efficiency of about 72% and peak Compressor Efficiency of about 69% - essentially losing only a small percent of its drive power to mechanical losses.

On the other hand, if we want to look at a worse case scenario, we'd consider a "friction drive" centrifugal supercharger. In this case we're relying on the friction (bad word already) of rollers or balls to provide the step-up ratio from our input pulley to drive our centrifugal impeller wheel to speed of 60,000 RPM - 80,000 RPM - along with seals and bearings (at least 1 seal and 2 bearings) at that same high speed. This type of device will have an adiabatic efficiency of about 72% and a Compressor Efficiency of about 31%. So, at least half of the input power put into the belt for this device is consumed by the drive system to get the compressor wheel up to the speed and compress the air.

Just because a device has low Compressor Efficiency dosen't mean that it can't make a lot of power, it just means that it will consume more power when doing it. Top Fuelers are a great example of this, while they have a SC that probably has less than 45%-50% Compressor Efficiency, they still make thousands of HP because they have the capability of moving huge amounts of air. You need to move enough air to make the power you are desiring, but the SC with the highest Compressor Efficiency will make the most power (with all else - intercooler, throttlebody, etc being the same).

Now I've pretty much provided you with the best and worst examples that exist in the SC market today, everything else out there falls somewhere between these two examples. If you're an OEM, you have access to this data - most OEMs have test stands to acquire this data themselves or have contracted test facilities that can perform the tests for comparison purposes.

Finally there is cost which is a tough one, but you have to hit the other hurdles to get to this point. Turbochargers are the big competition in this area, turbocharger device cost is cheap, but installation cost is not.

As usual, great information, well articulated.