How do I get more boost from my supercharger? The simplest way is to increase the speed at which the supercharger spins in relation to engine RPM. To do this either you swap out the lower "crank" pulley for a larger one, or swap out the upper pulley on the supercharger itself with a smaller one.
What is boost on a supercharger?
As we told you in Blower Basics (Part 1), boost is the amount of air pressure created by your supercharger and is the result of a combination of factors: engine displacement, blower displacement, and blower drive speed. A proper amount of boost is good—very good.
Can a carburetor stop a supercharger from boosting?
If your carburetor can't provide enough fuel and air, you can't take full advantage of your supercharger and you won't be able to make maximum boost. In addition to providing fuel for the motor, the carburetor also is the restriction through which air must pass to get into the blower and the motor.
Why does the supercharger lose boost at lower blower speeds?
This is because at lower blower speeds, the clearances between the superchargercase and the rotors allows for air "leakage" with some loss of boost efficiency.
How do you increase boost from a blower?
On a given size blower and a given size engine, boost can be increased by running the blower faster in relation to the engine's speed (overdriving) or it can be decreased by running it slower (underdriving). As a very rough rule of thumb, you typically want to run larger blowerson larger engines.
How to increase boost on blower?
On a given size blower and a given size engine, boost can be increased by running the blower faster in relation to the engine's speed (overdriving) or it can be decreased by running it slower (underdriving). As a very rough rule of thumb, you typically want to run larger blowerson larger engines.
What is root supercharger?
Roots superchargers are "external compression" blowers because the air compression takes place outside of the supercharger. Roots type superchargers first appeared in automotive applications as far back as the 1930s.
How many levels of superchargers does Weiand have?
Obviously, the amount of boost your supercharger produces is going to be a factor in choosing a camshaft. Weiand offers three different levels of superchargers, and each requires a different type of cam.
What are the different types of superchargers?
There are currently three basic types of superchargers being sold in the performance market today: the Roots type, centrifugal, and "screw" type. We'll use the terms supercharger and blower interchangeably. The centrifugal superchargeris very similar to a turbocharger, except the centrifugal supercharger is driven by a belt off the engine, ...
Why does a blower not produce much power at low engine speeds?
As a result, these units typically do not produce much power at low engine speeds because the impeller is not spinning fast enough to make much boost. If it were even possible to gear the blower so that it would spin fast at low engine speeds, it would then make too much boost at higher engine speeds.
What is a wastegate in a turbo?
Turbos employ a device called a "wastegate," which bypasses exhaust gas past the turbo when a certain boost limit is reached. The screw type blowerappears somewhat similar to a Roots type blower from the outside, but the internal rotors are quite different.
How much boost pressure should I use for a stock engine?
Most stock engines are equipped with cast pistons, cast crankshaft, two bolt main caps, and a small camshaft, requiring you to run very low boost pressure of 3 to 5 pounds maximum. Higher boost levels will cause detonation and engine failure. To run boost levels from 6 to 10 pounds we recommend the following: .
What is boost in a supercharger?
As we told you in Blower Basics (Part 1), boost is the amount of air pressure created by your supercharger and is the result of a combination of factors: engine displacement, blower displacement, and blower drive speed. A proper amount of boost is good—very good. A supercharger creating the optimum amount of boost can produce substantial power ...
Why does my engine have a high boost?
This is because the boost pressure can’t get into the engine cylinders efficiently and begins to build up within the intake manifold .
Why use a bigger blower on a bigger engine?
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. 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.
What is the effective compression for 92 octane gasoline?
For street engines running on 92 octane gasoline, you should keep your effective compression to 12.0:1 or below, according to Weiand. Once you exceed the 12.0:1 effective compression mark, detonation begins to become more likely. Naturally, you can attempt to control detonation with boost retards and other modifications, ...
How much more air does a full throttle engine need?
For example, at full throttle, your engine is going to need about 50 percent more air than it did before the blower was installed. If your carburetor is incapable of flowing the necessary airflow, you will have lower boost. Boost readings are typically observed or measured at the intake manifold.
Is too much boost bad?
Too much boost can be bad—very bad. It can lead to detonation, which can be catastrophic in forced induction engines. With assistance from the supercharger experts at Weiand, we’ll help you zero in on the safe, optimal amount of boost for your street application.
Is a supercharger good?
A proper amount of boost is good—very good. A supercharger creating the optimum amount of boost can produce substantial power gains and/or improved starting and low-end performance, depending on the supercharger style. Too much boost can be bad—very bad. It can lead to detonation, which can be catastrophic in forced induction engines.
