The Raceline direct-to-head throttle body range comprehensively covers all performance levels and Ford and Mazda Duratec engine types. Starting with a 45mm option which has proven ideal up to 250bhp, we then have a 48mm option for 250bhp+, and then a ported 48mm and a 50mm option for the high end performance and larger capacity engines. Using the well proven and reliable Jenvey 'butterfly' injection throttle design, the direct-to-head throttles are the lightest and most cost effective throttle body arrangement on the market. Tapered and roller-barrel throttles are proving popular for high-end engines builds these days, but by porting and optimizing a DTH throttle, the same results can be achieved for a much lower price - and they're more reliable and much lighter!The standard Duratec direct-to-head throttles sit at the same 17° angle as the cylinder head port and come machined with o-ring grooves to seal directly against the head. As with conventional throttle body sets, the direct-to-head throttles come with idle bleed adjusters and optional injector ports. The arched direct-to-head throttles (please see middle photograph above) are machined in the same way but designed to sit canted over to suit 10° engine applications such as the Mazda MX5 or any aftermarket application where the Mazda gearbox is used.Fuel rails are available to allow the injectors to operate in the throttle body or in the cylinder head. The more popular throttle body fuel rail is available with push-on or -6 fittings. The fuel rail for the cylinder head makes use of the standard Ford non-adjustable regulator. Blanking plugs can be supplied to blank off the injector ports in the cylinder head or throttle body. Stand alone fuel pressure regulators are available with a set fuel pressure or fully adjustable.A range of ram pipes, air filters and throttle linkages is available for both the 45mm, 48mm and 50mm throttles. If you do not see a suitable component listed, please contact us.