2″ 4150 Restrictor Carburetor Spacer
Dirt racing spacers for late model racing
Part number (SKU): UPM-4150-2RL
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Original Price: $190.00
In Dirt Late Model racing, when the track gets dry slick, even the best handling cars have trouble with over spinning the tires under acceleration. For that, Ultra Pro Machining has introduced a restrictor carburetor spacer. The spacer can be fitted with many sizes of removable inserts and takes away enough horsepower to give more throttle control, but not so much that you will feel down on power to the rest of the competition. The spacer is available in a straight spacer, or an angled spacer.
There are many manufacturers producing open design carburetor spacers today many of which do little other than increase plenum volume. The plenum volume effects the wave actions in the manifold also know as ram charging. Changes to this wave action may or may not result in an increase in performance based on the characteristics of your engine. However a properly designed carburetor spacer can perform other functions that will increase power regardless of the particular characteristics of the engine. Air flows poorly over sharp edges, which is why carburetors have a radius at the entry of each barrel. But air also has problems exiting through a hole with sharp edges ie the carburetor base plate. By adding one of our Hi-Flow spacers to this system the air may diffuse outward instead of traveling in a straight path. This effectively reduces the exit losses of the airflow through each barrel allowing any given carburetor to flow more air. Our Hi-Flow spacers also help the airflow turn into the runners. The diffusion action gradually increases the cross-sectional area of each barrel therefore the flow must slow down. This reduction in velocity decreases the kinetic energy of the flow and makes it easier for it to change direction. With the Hi-Flow spacer the air temporarily slows entering the plenum turns and accelerates down the runner. With no spacer the airflow crashes into the manifold floor loses all of its velocity and drops much of its fuel out in the process.