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If you’re enhancing an older vehicle’s performance to make the most of its power, you have many different options. One of the best ways to maximize power is to upgrade the carburetor. By improving how air and fuel get into the engine, you can enhance the vehicle's overall performance and get more horsepower with reliable and consistent combustion.
Edelbrock makes some of the most revered high-performance carburetors on the market, and knowing how to adjust an Edelbrock carburetor will help you achieve the performance you’re after.
Knowing how to tune an Edelbrock carb should be the first step after installing one. Fine-tuning the carburetor to meet your vehicle’s needs and enhance its horsepower is crucial. You can make a few different adjustments to optimize it.
One of the most straightforward solutions for setting up an Edelbrock carburetor is to adjust the idle air and fuel mixture. There are two screws on the front of the carb that adjust the amount of air at idle. To adjust them properly, first turn both of those screws until they are just tight enough to seat, making sure that you don’t over-tighten them. Then, back them off by 1.5 turns. Start the engine and slowly turn the screws ⅛ of a turn until you get the highest and smoothest-sounding idle RPM. If you tighten the screws, this will be the lean-best setting, while loosening them will be the rich-best setting. This means the mixture is optimized for your engine and delivers the right ratio (whether rich or lean, to your preference) when the car is idling.
When learning how to adjust an Edelbrock carburetor, it’s easy to forget about the secondary barrels, which are essential for the car’s efficiency and power output. Unlike the original Edelbrock Performer Series, an Edelbrock Thunder AVS2 carburetor has a secondary air valve that controls the mixture for these barrels/air valves. Adjust the spring tension on that valve to ensure that it reacts accordingly with the engine RPMs, tightening it will delay the opening, while loosening it will cause it to open sooner.
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One of the main reasons to upgrade your carburetor is that it can improve throttle response. With a high-quality carburetor that’s properly tuned and adjusted, you can get the quick, responsive feel you want from your vehicle.
Most Edelbrock carburetors have an accelerator pump linkage that can be moved to different holes to get either a higher or lower fuel shot when the accelerator is pressed. The higher the hole is on the linkage, the leaner the shot will be. Depending on your engine and what you have done when learning how to tune an Edelbrock carburetor, getting a leaner or richer shot will enhance the acceleration response from the throttle. If you hesitate slightly or the engine bogs when pressing the accelerator, you may need to adjust to a richer shot. If the acceleration feels slower than usual, a leaner shot will give the carb more fuel and improve the pedal's responsiveness.
Any kind of vacuum leak within your vehicle’s engine can cause problems with performance from idle (which usually is higher with a leak) to acceleration (possible lean condition). After installing your new Edelbrock carburetor, check for any vacuum leaks around the housing, specifically around the base gasket, hoses, or other connections. One of the best ways to do a vacuum leak test is to start the engine and let it idle for until warm. Then, spray carburetor cleaner on the connections and around the carb. If you notice any change in the RPM or how the engine sounds, this is a sign of a leak in the area where you sprayed. Sealing up the leak or replacing a damaged component should improve the carb’s performance.
Once you learn how to set up an Edelbrock carburetor, there are other things you can do to make sure that your new carb is operating at its peak performance. Setting your engine up to help the carb deliver air and fuel efficiently will help you make the most of the upgrade.
Since the carburetor determines the mixture of air and fuel, it is a good idea to ensure that your engine's airflow is unobstructed. A high-flow air filter and cleaner assembly provides maximum air going into the carburetor. You can also use a carburetor spacer to increase the intake manifold volume for racing applications, as it will raise the rpm power band.
In addition to your engine's airflow, you should ensure the fuel delivery system is in good working order. First, ensure the fuel pressure is right for your carb. For most Edelbrock carburetors, the fuel pressure should be between five and six psi for optimal performance. You should also check the age and mileage of your vehicle’s fuel filter and see if it needs to be replaced before adjustment of an Edelbrock carburetor. A clog in the fuel filter could cause an adjustment to be unnecessary or cause you to chase down an issue that isn't related to the carburetor.
If you want your vehicle to have the highest-quality parts and accessories, no matter what kind of car you have or what type of upgrade or repair you’re doing, JEGS is here for you. Browse an extensive selection of products and have your items sent straight to your door.