Drag Race Air Cleaner Bases and CFD Inserts

CFD 4150 4 Hole Direct Flow AC 10613
CFD 4150 4 Hole Direct Flow AC 10613

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s07 SummitRacing 132


 Best run with  no air cleaner or base.





660' mph-80.41



1320 mph-100.70


Best run with R2C CFD Flow Director.  The quickest the car has ever gone! 





660' mph-80.75



1320 mph-100.92

 Contact us at racing@r2cperformance.com with questions or selection of the best performing products for your application.


CFD 4150 4 Barrel Drag Race Air Cleaner Bases with Direct Flow Technology.

Introducing the most powerful and versatile Drag racing air cleaner bases and Flow Directors for Holley 4150 4 barrel applications!  Great for use with hood scoop pans for improved flow and maximum power.

Easy double digit horsepower gains !


Eliminates raw edge carburetor entry turbulence resulting in reduced e.t.'s and MPH increases  

Quickly Add's Dyno Proven Double Digit Horsepower and Torque Gains!

  • More Horsepower and Torque than any racing base or Stack available today! 
  • 3 CFD 4150 shaped flow director configurations to choose from
  • Quick Release Flange Mounting System Eliminates Flow Path Turbulence - No Stud Required! - Spring Plungers Optional - 2 Req.
  • Easy interchange versatility that allows you to dyno tune and track test, quickly maximizing horsepower based on the power band of each race car
  • Excellent Performance Gains on All Applications, Including Those with Hood Scoop Pans such as Dragsters, Comp, S/S, etc.



Direct fit race filters for use with CFD Flow Directors. Great for applications with limited filter space. Extremely low restriction, high flow capacity.

CF10507  --  4BBL Race Filter for CFD Flow Director - 3" tall

Custom heights available - inquire.



Months of design evaluation and flow bench testing, followed by extensive dyno tests (over 300 pulls!) conducted by the most respected names in race engine and carburetor assembly, have resulted in the best flowing, highest power producing air cleaner bases for Holley 4 barrel race applications.

R2C engineers developed each precision base shape to augment the venturi profile of the popular 4150 series Holley carburetor, resulting in dramatically smoother entry profiles and reduced restriction, allowing precision drag racing carburetors to perform at optimum levels and engines to produce increased power and torque. When used in conjunction with R2C Drag Race filter configurations, nothing comes close to the performance advantage R2C CFD 4150 4 barrel bases offer racers in applications from Bracket and Stock class cars to the highest horsepower, naturally aspirated drag race engines.

CFD 4150 Holley Flow Directors are offered in three configurations, allowing racers to select the precision contour that maximizes overall performance based on their individual applications.

      CFD 4150 w/Air Cleaner Base (for use with or without filter element )

  • AC10615 Direct Flow Base 1" Height Open
  • AC10616 Direct Flow Base 1" Height 4 Hole
  • AC10617 Direct Flow Base 2" Height Open
  • AC10618 Direct Flow System - Includes 3 Flow Director Center Components and Base for easy interchange. Use with a filter Element.

      CFD 4150 Shaped Flow Director w/o Air Cleaner base ( Applications without Air Filter )

  • AC10612 Flow Director 1" Open
  • AC10613 Flow Director 1" 4 Hole
  • AC10614 Flow Director 2" Open

      R2C0629A37 Quick Release Spring Plunger Mounting - 2 req.  Eliminates the need for an air cleaner stud.

       Maximum Flow Director Diameter is 7 3/4"

      Now shipping........ contact your favorite retailer and order yours today!

      *Available soon:  CFD 4150 Direct Flow technology for Holley carburetors equipped with choke towers as well as Dominator, Braswell 4825, Quadrajet and Thermoquad applications.

 *Patents Pending


Use the following race filters for drag race applications.

  • R10509 14" x 3"
  • R10510 14" x 3.5"
  • R10511 14" x 4"
  • R10512 14" x 5"
  • R10531 14" x 4" Drag Race Special - Offset Media Configuration - Maximum Power with drop bases  * 5" total height
  • R10532 14" x 5" Drag Race Special - Offset    * 6" total height

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