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How much Overdrive should a blower have?

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How much Overdrive should a blower have?

Our first whack with the 8-71 used a 63-tooth pulley on the top and a 54 on the bottom for a drive ratio of 0.857:1 (14.3 percent underdriven) making peak boost of 7.6 pounds at 5,900 rpm and delivering 724 lb-ft at 4,800 rpm and 754 hp at 5,900 rpm.

How much boost does a 871 blower make?

Our first whack with the 8-71 used a 63-tooth pulley on the top and a 54 on the bottom for a drive ratio of 0.857:1 (14.3 percent underdriven) making peak boost of 7.6 pounds at 5,900 rpm and delivering 724 lb-ft at 4,800 rpm and 754 hp at 5,900 rpm.

What do blower numbers mean?

“That blower had a 15-inch long rotor. From that day forward, a 15-inch rotor blower is called a 6-71, a 16-inch long rotor is called an 8-71, and a 19-inch long rotor is a 14-71 blower. As you can see, the bigger the number, the longer the rotor, and the more power it will make.” The Screw Blower.

How do you overdrive a supercharger?

For a substantial change in boost, you can interchange the top pulley for the lower pulley and change the blower from underdrive to overdrive. You can swap pulleys to approximately double the amount of boost you will get.

How much boost can a 671 blower make?

Driven 11 percent under, the 6-71 produced a boost curve that began at 4.2 psi at 3,300 rpm and rose to 8.3 psi at 6,400 rpm. This pulley combination produced peak power numbers of 602 hp at 6,400 rpm and 551 lb-ft of torque at 4,700 rpm.

What do blower numbers mean?

“That blower had a 15-inch long rotor. From that day forward, a 15-inch rotor blower is called a 6-71, a 16-inch long rotor is called an 8-71, and a 19-inch long rotor is a 14-71 blower. As you can see, the bigger the number, the longer the rotor, and the more power it will make.” The Screw Blower.

How do you overdrive a supercharger?

For a substantial change in boost, you can interchange the top pulley for the lower pulley and change the blower from underdrive to overdrive. You can swap pulleys to approximately double the amount of boost you will get.

How much HP does a 871 blower add?

The boost supplied by the 8-71 increased the peak power output from 651 hp to 898 hp and torque from 579 lbs. ft. to 764 lbs ft.

How much HP does a blower add?

What compression do I need to run a supercharger?

7.0:1 to 9.0:1 compression ratio. The optimum compression ratio is 8.0:1. Higher than 8.0:1 is not necessary or recommended. Fuel, ignition timing, and total boost could become critical factors.

How do I get more boost from my supercharger?

The amount of air pressure over normal atmospheric pressure a supercharger develops is called "boost." Spinning the same belt-driven blower faster at a given rpm generates more boost. This is accomplished by changing the ratio between the crank pulley and the drive pulley.

How much boost does a supercharger give?

A supercharger increases the pressure of the air entering the engine so that it's more than atmospheric pressure. Atmospheric pressure at sea level is 14.7 psi (pounds per square inch), so a typical supercharger providing an increase of between 6 and 9 psi boosts the engine's air consumption by about 50 percent.

Who makes the best roots blower?

Since its founding in 1974, Littlefield Blowers has been recognized as one of the top roots blower and supercharger manufacturers in the U.S. We serve a wide variety of performance-oriented customers for land, water, or air—ranging from fast-accelerating quarter-mile race cars to record-chasing land speed cars to ...

How do you measure blower boost?

Calculating Boost Ratio Add the boost pressure desired (5 Psi) for the engine to 14.7 Psi (atmospheric pressure). Divide this answer by 14.7 and this gives the boost pressure ratio. (21.7/14.7=1.476) This is the boost pressure ratio above atmospheric pressure.

What does 671 mean in a blower?

Introduced in 1938 and produced well into the 1990s, the 6-71 is a two-stroke, six-cylinder diesel. In GMC diesel nomenclature, 6 represents the number of cylinders, while 71 represents the cubic-inch displacement per cylinder.

How many cubic inches is a 671 blower?

A 671 pushes through 426 cubic inches.

Does supercharger size matter?

(Supercharger) Size Matters As engine size goes up, the supercharger will begin to make less boost; therefore, it's ideal to use a larger blower on larger cubic-inch engines.

How do I get more boost from my supercharger?

The amount of air pressure over normal atmospheric pressure a supercharger develops is called "boost." Spinning the same belt-driven blower faster at a given rpm generates more boost. This is accomplished by changing the ratio between the crank pulley and the drive pulley.

How do you size a supercharger for an engine?

In terms of sizing, it all comes down to the volume of air that the supercharger can cram into the cylinders of the engine each time the supercharger spins around. The ratings for superchargers are therefore given in L/rev (litres per revolution) or cc/rev (cubic inches per revolution).

What do blower numbers mean?

“That blower had a 15-inch long rotor. From that day forward, a 15-inch rotor blower is called a 6-71, a 16-inch long rotor is called an 8-71, and a 19-inch long rotor is a 14-71 blower. As you can see, the bigger the number, the longer the rotor, and the more power it will make.” The Screw Blower.

How do you overdrive a supercharger?

For a substantial change in boost, you can interchange the top pulley for the lower pulley and change the blower from underdrive to overdrive. You can swap pulleys to approximately double the amount of boost you will get.

How much horsepower does a supercharged 454 have?

SC HELLION 454 This CBM engine is Supercharged, it puts out 900+ hp @ 6800 RPM's and 875 ft-lbs of torque using 10lbs of boost. It has a compression ratio of 9.1.

What is a 10 71 blower?

Littlefield 10-71 polished alum. competition blower. This blower has nylatron and Teflon stripping to insure maximum efficiency on your engine. Rotors are billet and hard anodized for a long lasting supercharger and a tighter inside tolerance creating a more efficient supercharger.

How much horsepower does a Weiand supercharger add?

Using the supplied 3-inch blower pulley and 6-inch crank pulley, the Weiand 177 supercharger produced a peak of 6.3 psi and increased the power output of the 350 to 405 hp and 446 lb-ft of torque.

Can a supercharger damage an engine?

Superchargers use air to increase power, meaning that overboosting the supercharger will blow hot air into the engine and could cause damage.

Can you have a blower without a supercharger?

Every blower is a supercharger, but not every supercharger can be a blower. A blower is just another name for a supercharger, particularly roots-type supercharger, which is probably one of the oldest styles of supercharger.

What size blower do I need for my engine?

According to Weiand, you typically want to run larger blowers on larger engines. Assuming a constant speed ratio between the engine and the blower, a larger blower will make more boost than a smaller one on the same size engine.

Does blower size matter when choosing a supercharger?

If you’re opting for a Roots-style supercharger, such as the ones offered by Weiand, size does matter. According to Weiand, you typically want to run larger blowers on larger engines. Assuming a constant speed ratio between the engine and the blower, a larger blower will make more boost than a smaller one on the same size engine.

What happens if you put a bigger blower on an engine?

At some point, the blower would become inefficient and could actually heat up the air, causing loss of boost. Bottom line: larger blowers are for larger engines. When shopping for a supercharger, you’ll notice boost levels are noted in ranges—as in 6 to 8 psi.

How much SCR should I run with a blower?

Roots blowers can't get away with the compression and boost that a centrifugal superchargers (pro charger, paxton, vortech), and turbos can. For a pump gas street type blown engine I would run 7.5:1 to 7.8:1 SCR.

Below you will find two interesting articles on a similar topic 👇

Can you run a bigger blower on a smaller engine?

What does a blower motor do on a car?

Tired of looking for a video for your question?

Video Answer below 👇

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