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Home  /  Intake Hardware  /  Individual Throttle Bodies  /  DCOE Type

PRO-STREET throttle body DCOE sizes 40mm to 48mm

Pro Street Series are available in 40, 45, 48. Housing to shaft lip seals installed behind bearings for extra sealing under high vacuum
Idle by pass air bleed screws for super smooth idle and to aid emissions tuning.
O'ring seals on front and rear mounting faces. (Vacuum port for map sensor optional extra)

Product Code:

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Including GST for Australian Customers

AUD $515.00 (ex GST)
for International Customers

Product Details


Every single throttle bore and throttle plate are measured and matched as a pair to ensure the most perfect throttle fit and consistency across every EFI Hardware throttle body.


We have lip seals behind the throttle shaft bearings to stop grease from being sucked out of the bearings under high intake runner vacuum. These are turned around on boosted applications so there is no boost leakage and also stops the bearing grease getting evacuated from the throttle shaft the bearings. 

We ask you if you are going to run your engine Boosted, or Naturally Aspirated so we can install the Lip Seals in your throttle bodies in the appropriate way to suit your application.


DCOE Throttle Body Technical Drawing


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.

40mm - 45HP/34KW* per throttle.

45mm - 54HP/40KW* per throttle.

48mm - 64HP/48KW* per throttle.

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



In the past, 12° throttle plates were the industry standard.  The problem with 12° throttle plates, is that as the plates are moved off the closed position, the change in airflow is huge.  It makes it very difficult to drive smoothly at lower throttle openings.

At EFI Hardware, we only use 6° throttle plates.  This improves off idle and cruise driveability making your vehicle far more enjoyable to drive.

Manufactured from 601 Cast aluminium 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.