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

Introducing the most powerful and versatile racing air cleaner bases for Holley 4150 4 barrel applications!   Bolt-on double digit power gains.

Precision Booster Signal and entry profile Increases torque and provides crisp throttle response.  improved pull out of corners and additional straightaway speed.

easy double digit power and torque gains

   +9 rear wheel horsepower gain on a 604 Crate! 

   +16 engine horsepower gain on a Dirt Modified!

In stock for immediate shipping. Order yours today!

Months of design evaluation and flow bench testing, followed by extensive dyno and track tests (now over 400 independent 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. Every application from Stock Cars to unlimited Late Models and Big Block Modifieds have achieved significant gains in power and response/driveability.

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 and a much stronger and consistent venturi/booster signal, allowing precision racing carburetors to perform at optimum levels and engines to produce increased power and torque. When used in conjunction with R2C Late Model/Modified air filter configurations, nothing comes close to the performance advantage R2C CFD 4150 4 barrel bases offer racers in applications from Stock cars to the highest horsepower open engines.

CFD 4150 4 barrel air cleaner bases are offered in three configurations, allowing racers to select the precision contour that maximizes overall performance based on their individual applications. Strong and durable, R2C CFD bases won't dent or deflect, causing filter sealing issues.

* Patents Pending

• More Horsepower and Torque than any racing air cleaner base available today! 

• 3 CFD 4150 shaped flow director configurations to choose from

• Ultra strong composite Nylon Construction - No bending, dents and it runs cooler.

       Contact your favorite retailer and order yours today!

 Modified and Late Model Engines

       Dirt Modified dyno testing 

       680 HP Baseline

       696 HP using R2C CFD 4150 Direct Flow race air cleaner base - w/2 pulls at +18 HP!

       Excellent power and torque gains throughout the power band.

       Attention 602 and 604 Crate Engine users

      maximum power to keep you in front!

          AC10617 CFD 4150 base and R10523 filter is the best combination.  

           Use lid AC10521 or AC10520  

        9-14 rear wheel horsepower gains!

AC10615 CFD 4150 Air Cleaner Racing Base - 1" Height Above Flange Open Flow Director      1 3/8" Drop

AC10616 CFD 4150 Air Cleaner racing Base - 1" Height Above Flange 4 Hole Flow Director    1 3/8" Drop

AC10617 CFD 4150 Air Cleaner racing Base - 2" Height Above Flange Open Flow Director          3/8" Drop

AC10618 CFD 4150 Race System - Includes 3 Shaped Flow Directors, Base and gaskets.            
                                                                                     Unassembled components for testing. (No Plungers)

*New

R2C CFD 4150 bases and Flow Directors are now available for Holley carburetors that maintain the choke housing such as the Double Pumper series, Street Avenger ^TM and Ultra models.

Bolt-On Double Digit Horsepower and Torque Gains!

AC10709 Base - Fits Choke Towers with a flat casting and 1.05" Tall Choke Tower

AC10710 Base - Fits Choke Towers with angled castings at the bowl vent and 1.39" Tall Choke Towers

*Holley Ultra HP - Use AC10617 due to extended bowl length.

    Applications for Braswell 4825 carburetors available soon!