Home » EFI Hardware Products » Throttle Body Kits » Duratec Kit » Duratec 4 cyl Pro Race Kit 50/48/45
Direct to Head Ford Duratec 4 cylinder Pro-Race throttle body Kit: tapered bore size 50/48/45 (50mm at ram tube flange/48mm butterfly/45mm port before blending to port shape. Kit Includes:- 2 x Pro-Race Duratec throttle bodies, 1 x Pro-Race fuel rail kit, Pro-Series joiner balancer with cable pull & throttle stop linkage, throttle cable bracket & 4 x Pro-Series ram tubes. (TPS, Regulator, regulator mounting kit and injectors not included P.O.A)
Duratec Pro-Race Throttle Body Kit Contains:
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.
Your cart is empty