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PRO-RACE 4cyl DCOE throttle body kit 50/48/45/43/mm Throttles - Tapered Bore

These are our flagship Throttle Bodies. The Pro-Race series have all of the features of our Pro-Street series.

Our tapered bore throttles have flat-machined throttle shafts for greater air flow for increased power &
torque gains.

NOTE: Manifold not included. Black anodizing on the fuel rail is optional.


Product Code:
800-905
Availability:
Available

Product Options









$1,974.50
Including GST for Australian Customers


AUD $1,795.00 (ex GST)
for International Customers


Product Details

BOOSTED VS NATURALLY ASPIRATED:

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.



  


FULLY ASSEMBLED VS SUB ASSEMBLED KIT:


We want to supply your Throttle Body Kit just the way you want it.


That's why we offer both Sub Assembled Kits, and Full Assembled Kits.


FULLY ASSEMBLED KIT:

By choosing the Fully Assembled Option above, you will receive:

- Each of your Throttle Bodies is precision factory assembled

- Throttle Shafts cut to correct lengths to suit your manifold

- Linkages are fitted and adjusted to ensure correct and smooth operation

  Note: Although we will supply a great linkage fitment, final linkage adjustment

  can only be carried out once the engine is running

- TPS "D" drive on the end of the shaft you stipulate so it's in the best position on your engine

- We may contact you with a few questions to ensure we supply the kit assembled to best

  suit your application


SUB ASSEMBLED KIT:

By choosing the Fully Assembled Option above, you will receive:

- Each of your Throttle Bodies is precision factory assembled

- Throttle Shafts are left long so you can trim them to suit your engine and manifold

- Linkages are supplied for you to fit and adjust once you have trimmed your Throttle Shafts




4 Cylinder Pro-Race Throttle Body Kit Contains:


  • 2 x Pro-Race Tapered Bore Throttle Bodies - Sizes 43, 45, 48 or 50mm
  • 1 x Pro-Race single piece billet aluminium fuel rail kit
  • Pro-Series Joiner Balancer with Cable Pulley & Throttle Stop linkage option (Black) or
  • Pro-Series idler Shaft with Drop Links & Throttle Stop option (Black).
  • Throttle cable bracket & 4 x Pro-Series ram tubes (Black)
     
  • (Manifold and Fuel Rail Fittings are not included) P.O.A. for these items





LINKAGE SETUP:


There are two linkage options for this kit.

  • Centre Pulley and Joiner Balancer - will only work if your manifold has throttle body mounting bolts that allow your throttle shafts to align perfectly end-to-end without any offset.
  • Idler Shaft with Drop Linkages - This is the premium setup and can be used on a kit where the manifold has tilted throttles (to allow carburetor bowls to sit horizontally).

If your manifold allows the throttle shafts to align perfectly end-to-end, then you may choose either the Centre Pulley and Joiner Balancer option, or Idler Shaft with Drop Links option.


If your manifold has tilted throttle body mounting bolts, you must use the Idler Shaft with Drop Links option.





LINKAGE AND RAM TUBE COLOURS:


Due to overwhelming demand from our customers, we are transitioning our standard colour from Blue to Black.  Black is a classic colour, and goes with pretty much every engine bay colour and style.


This includes Ram Tubes, Linkages, Cable Pulleys, Drop Links, Bell Cranks, and more.


Don't worry if you love blue, you can still get your kit in blue.  There will be a small premium of $40 per kit to cover us sending out your kit of parts to be anodized blue.  If you would like blue anodizing, please let us know by typing in the notes area of your order.




ACCESSORIES:

PART NUMBERDESCRIPTIONIMAGE
H-MAPCOL4

4 Cylinder MAP Sensor Collector


If you are after great drivability with
great engine response, you should consider
using a MAP Sensor Collector for the ultimate
blend of power, throttle response and 
tunability.


 



QUALITY ASSURANCE:


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.





THROTTLE BODY TECHNICAL DRAWING


DCOE Throttle Body Technical Drawing


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 - 45, 48, 50 or 52mm

This then tapers down to a short parallel section for the throttle plate - 43, 45, 48 or 50mm

There is a second taper down to the outlet flange of the throttle body - 40, 43, 45 or 47mm


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.


43mm - 50HP/38KW* per throttle - with the tapered bore giving a potential for 5% above this figure.

45mm - 54HP/40KW* per throttle - with the tapered bore giving a potential for 5% above this figure.

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

50mm - 72HP/54KW* 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.



HIGH PERFORMANCE FUEL SYSTEM PLUMBING TECHNICAL DIAGRAM


Setting up your fuel system right the first time is easy if you follow the right instructions.


Fuel System Inline 4 Cylinder Engine Instructions



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.



EFI HARDWARE PRODUCE 6° THROTTLE PLATES


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.




GETTING THE RIGHT BALANCE




The best idle and cruise quality will only occur when every throttle has exactly the same airflow.


The only way to achieve this is to adjust the linkages and/or idle bypass screws and use a tool to measure the airflow at each throttle.


Getting the right balance is not a should, it is a MUST.


PART NUMBERDESCRIPTIONIMAGE
880-100throttle body sync tool

SKF_Racing_Logo

We now recommend

and use SKF bearings.