pro-race 4cyl DCOE throttle body kit 50/48/45mm - Tapered Bore

These are our flagship Throttle Bodies. The Pro-Race series have all of the
features of our Pro-Street series throttle bodies, plus tapered bores &
flat-machined throttle shafts for greater air flow for increased power &
torque gains.

Product Details

4 Cylinder Pro-Race Throttle Body Kit Contains:

• 2 x Pro-Race Tapered Bore Throttle Bodies - Sizes 50/48/45
• 1 x Pro-Race single piece billet alluminium fuel rail kit
  • Choice of -6 or -8 AN Fuel fittings
• Pro-series 6 Cylinder Linkage Kit - Includes:
  • High Quality Rod Ends
  • Drop Link - 6061-T6 Aluminium
  • Throttle Stop With Lever Arm - 6061-T6 Aluminium
  • Cable Pull - 6061-T6 Aluminium
• Throttle cable bracket & 4 x Pro-Series ram tubes
• Comes fully assembled - Can also be purchased as a parts kit (throttles always come factory pre-assembled) , call for subassembled price.
   
• (Manifold, TPS and injectors not included) P.O.A. for these items

TAPERED BORE THROTTLES

 

Tapered Bore Throttles have a clear advantage over Parallel Bore Throttles at increasing power and torque. By accelerating the air through a venturi (in this case a tapered bore) the air speed through the throttle body is increased.  This enhances the engine cycle's scavenging effect to provide more air and fuel in the combustion chamber and therefore more power and torque.

 

The Tapered Bore has 3 sections:

Inlet from ram tube - 50mm

This then tapers down to a short parallel section for the throttle plate - 48mm

There is a second taper down to the outlet flange of the throttle body - 45mm

HP RATINGS

 

HP/kW Ratings vary from engine to engine.  The power ratings given here are only a guide, and are not absolute power ratings.  Engine power is determined by intake, exhaust, cylinder head design, camshaft design, compression ratio, fuel type and quality and many other factors.

 

48mm - 64HP/48KW* per throttle - with the tapered bore giving a potential for 5% above this figure.

 

*This number is a guide only and should be used in conjunction with real-world experience.

PROFESSIONAL GRADE MANUFACTURE

Manufactured from 601 Cast aluminum and heat treated before being CNC machined.

The butterflies are measured for each bore & precision machined to a 0.0005"" tolerance.

Butterflies are secured to centreless ground brass shafts with split screws to ensure reliability and serviceability.

All are fitted with bearings rather than bushes to eliminate axial shaft movement.

Low stiction bearings for sharp throttle response.

We now recommend

and use SKF bearings.