IDA Throttle Body Mounting Explained

When upgrading your engine's performance, the throttle body plays a pivotal role in dictating how much air enters the combustion chamber. For those looking at the esteemed IDA style throttle bodies, understanding their mounting is paramount. These units, known for their quality and customisation, offer a range of options, but their placement and orientation can significantly impact installation and performance. This guide delves into the specifics of where IDA throttle bodies are mounted and what you need to consider before making your purchase.

Understanding IDA Throttle Body Mounting Orientation

The primary consideration when mounting IDA throttle bodies is their orientation relative to the engine. This isn't a one-size-fits-all scenario, and the design of your intake manifold will dictate the correct configuration. EFI Hardware offers IDA throttle bodies with specific mounting orientations to ensure compatibility with various rotary engine manifolds.

Wide vs. Narrow Spacing to the Engine

IDA throttle bodies feature a mounting flange with bolt spacing. The key distinction lies in whether this spacing is 'wide' or 'narrow' with respect to the engine block. This difference is crucial because it determines how the throttle body will align with your existing manifold.

Right Hand Drive Cars:

• Wide Spacing To Engine: This configuration positions the wider bolt spacing of the IDA flange closer to the engine block.
• Narrow Spacing To Engine: Conversely, this setup places the narrower bolt spacing of the IDA flange nearer to the engine block.

Left Hand Drive Cars:

• Wide Spacing To Engine: Similar to the RHD configuration, the wider bolt spacing is closest to the engine.
• Narrow Spacing To Engine: Again, this means the narrower bolt spacing is nearest to the engine block.

Why is this important? If you are purchasing IDA throttle bodies and already have an intake manifold, you must select the correct mounting orientation. Choosing the wrong one will result in the throttle body not fitting your manifold, necessitating a return or exchange, which can be a costly and time-consuming inconvenience. Always verify your manifold's bolt spacing before ordering.

Throttle Body Sizing and Bore Types

Beyond mounting orientation, IDA throttle bodies come in various sizes and bore types, each offering distinct advantages:

Parallel Bore Sizes:

• 50mm Parallel Bore: A standard and popular choice, offering a good balance of airflow and throttle response.
• 55mm Parallel Bore: For engines requiring a higher volume of airflow, the 55mm option provides increased capacity.

Tapered Bore Sizes:

Tapered bores are a key feature that can enhance torque and drivability. EFI Hardware specifically highlights the benefits of their tapered bore designs:

• 52/50/48mm Tapered Bore: This configuration features a 52mm ram tube opening, a 50mm butterfly valve, and tapers down to a 48mm opening at the manifold flange. This design is intended to improve torque delivery throughout the rev range.
• 55/53/50mm Tapered Bore: Offering a larger intake at 55mm, with a 53mm butterfly and tapering to 50mm at the flange. This is for high-performance applications where maximum airflow is desired.

Benefit of Tapered Bores: Customers have reported consistent torque gains with tapered bore throttles over traditional parallel bore designs, without sacrificing peak power. This translates to better acceleration and a more engaging driving experience.

Air Inlet and Ram Tube Options

The choice of air inlet and ram tubes also plays a role in performance and sound:

Important Note: All assembled air filter kits feature lock-wired ram tube bolts for added security and reliability.

Manifold Considerations

When purchasing a new manifold to go with your IDA throttle bodies, EFI Hardware specifies that their rotary manifolds are designed with the wide bolt spacing toward the engine. If you are unsure about your manifold's configuration, it is essential to contact EFI Hardware before finalising your order.

Porting the Manifold: For those opting for the 55mm bore throttle bodies, there's an option to 'Port Manifold to Match 55mm Bore Throttle Body'. This involves machining the intake manifold to perfectly match the 55mm opening, potentially improving airflow and performance. You can choose 'No' if you prefer not to port the manifold.

Throttle Position Sensor (TPS) and Actuation

A Throttle Position Sensor (TPS) is crucial for any engine management system. IDA throttle bodies are designed with a standard 8mm D-shaped throttle shaft and M4 mounting holes, allowing for various TPS options:

• No Throttle Position Sensor: If you have a compatible TPS already, you can opt out of this.
• Premium Contactless TPS: Offers enhanced durability and accuracy.
• Bosch Style TPS: A common and reliable option.

Drive-by-Wire (DBW): An option is available to add a Drive-by-Wire actuator. This replaces the traditional cable linkage with an electronic system, offering more precise throttle control and integration possibilities with modern ECUs. If considering DBW, ensure its compatibility with your engine management system and consult your tuner. Incorrect fitment or application of DBW systems is not the liability of EFI Hardware.

Fueling and Other Fittings

IDA throttle body kits can also be supplied with various fuel injector options, catering to different horsepower targets. Injector ratings are typically based on 3 BAR fuel pressure:

If no injectors are supplied, fuel rails will be configured for Bosch EV14 half-height injectors. Additionally, options for vacuum and oil fittings can be machined directly into the manifold if purchased from EFI Hardware.

Quality Assurance and Unique Features

EFI Hardware prides itself on quality. Every throttle bore and plate are measured and matched to ensure a perfect fit and consistent performance. Their commitment to improving drivability is evident in their use of 6° throttle plates, a departure from the older 12° standard. This finer angle significantly improves off-idle and cruise control, making the vehicle much more pleasant to drive in everyday conditions.

Boosted vs. Naturally Aspirated Applications

For engines running forced induction (boosted) or naturally aspirated setups, EFI Hardware implements specific lip seal configurations behind the throttle shaft bearings. These seals prevent grease from being drawn out under high vacuum (NA) or prevent boost leakage and maintain bearing lubrication in boosted applications. It is important to specify whether your engine is boosted or naturally aspirated when ordering to ensure the correct setup.

Frequently Asked Questions (FAQs)

Q1: How do I know which mounting orientation to choose?

A1: You need to check your existing intake manifold. Look at the spacing of the bolt holes on the flange where the throttle body mounts. Compare this to the 'wide' and 'narrow' spacing options offered by EFI Hardware. If unsure, consult your manifold's manufacturer or contact EFI Hardware directly.

Q2: What is the advantage of a tapered bore throttle body?

A2: Tapered bore throttle bodies are designed to improve torque delivery throughout the engine's rev range, leading to better acceleration and a more responsive feel, without compromising peak power output.

Q3: Do I need to port my manifold if I choose a 55mm throttle body?

A3: It is recommended for optimal performance, but not strictly mandatory. EFI Hardware offers an option to port the manifold to match the 55mm bore. If you choose not to, there might be a slight restriction at the manifold entry.

Q4: Can I use my existing Throttle Position Sensor (TPS)?

A4: Possibly. The IDA throttle bodies have standard mounting provisions. If your existing TPS has an 8mm D-shaft drive and fits the M4 mounting holes, it may be compatible. However, if you are unsure, it's safer to purchase a new, compatible TPS with your throttle body.

Q5: How do I choose the right fuel injectors?

A5: The choice depends on your engine's expected horsepower output. Refer to the provided table for horsepower ratings based on injector flow rate and fuel type (Pump Gas, E85, Methanol). For boosted engines, it's advisable to consult with EFI Hardware or your engine tuner.

Conclusion

The mounting of IDA throttle bodies, while seemingly straightforward, requires careful attention to detail, particularly concerning the orientation relative to your engine's manifold. By understanding the options available for bore size, ram tubes, and necessary accessories, you can ensure a smooth installation and unlock the full performance potential of your engine. Always double-check compatibility and, when in doubt, seek expert advice.