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sonic itb's

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Bigger is not always better

Typical logic implies that larger throttles will flow better making more power at higher RPM’s, while smaller throttles will generally provide more low and mid-range torque.  Something that is overlooked is how far away the throttles are from the port.  If two sets of ITBs have identical runner volume and taper, a small throttle can be placed near the port and larger throttle can be placed near the velocity stack and their airflow and velocity will be the same.  Thus, throttle size tends to get overemphasized when quantifying ITBs when larger throttles tend to be placed much further away from the port.

URGE Sonic ITBs throttles are with in 2” from the port opening vs 3-5” with other ITBs options.  Not only does this mean we can run smaller throttles and have better flow, but it also means better response as air only needs to fill the port vs port and runner when the throttles are opened.

Port Entry Optimization

A more important consideration is runner port entry design.  The idea is to maximize airflow with the smallest runner port area possible, producing optimal air velocity and maximizing torque across the broadest RPM range.  One area for improvement we looked at was port entry angle.  Based upon runner test flow data, changing the port entry angle a few degrees improved flow >10 CFM.  Since AT throttles are machined and not cast, we can make iterative changes as needed.

Custom Runner size

We tune the runner length and volume based upon your motor capability.  F20C pull the least amount of air so we keep our runner diameter to 55mm which improves response and torque for the smaller motors.  F22C, we step up to 60mm diameter as they can make more power.  For stroker 2.4-2.5 L, we step up to 65mm runner diameters to ingest more air and shape it properly as it enters the head.

Additionally, we can tun the length of the runners if someone is looking for peak power outside of the normal 7500-8500 RPM window or if someone is looking to make even more power with the 2nd harmonic vs the 3rd.  We would need to add quite a few inches of length to support that.

Shaftless Throttle

Lastly, another opportunity of improvement beyond throttle size and placement is the shape of the throttle itself.  Even at wide-open throttle, the bulk of the throttle blade and shaft can reduce airflow by 5-10%.  AT Power is an innovative induction company out of England that created a new throttle design that is “shaftless”.  Essentially, their throttles are a thin tapered blade that is CNC’d as a single piece with the rotating shaft.  With this innovative feature there is nothing needed to support the shaft inside the runner port.  AT Power’s testing proved their design reduces airflow by only 0.5% (vs 5-10% in traditional setups), essentially providing flow rates of barrel throttles without the cost or high maintenance.

Shaftless vs Typical Butterfly

We applied a custom port entry angle with AT Power runner design & 52mm shaft less throttles to come up with an optimal set of ITBs that maximizes air velocity.

ITB Flow testing data points

  • Ported head flow compared to various ITBs attached to head
  • URGE 52mm flowed the same as the 60mm Kinslers that have much larger ports
  • 50mm Jenveys flowed a little better than the AT Power 45mm

ITB Flow testing vs Velocity Head and Stock Manifold

ITB dyno testing to find the optimal throttle size

  • 52mm URGE designs vs larger 60mm Kinslers
  • Big cams and large Hytech header
  • URGE 52mm makes 10-15 ft-lbs more torque
  • Better Air Velocity due to matching flow rates with smaller throttle & port + shaftless throttle
  • 52mm URGE designs vs 45mm AT Power
  • Low & mid-range torque Identical, 45mm expected to have higher torque there
  • 52mm most likely has same velocity as it flows more with slight larger ports
  • 52mm edge out at higher RPMs, 45mm starts to choke around 330 HP

Based upon our results, we have chosen to offer 52mm ITBs.  The 52mm throttles have similar air velocity to smaller 45-48mm ITB’s, providing good low and midrange torque and similar air flow to larger 60mm throttles providing top end power.  With innovative R&D we feel we have made the optimal ITB’s for stock as well as fully built road race engines.

OEM fuel rail Integration

Although we have gone through many small iterations to continuously refine the Sonic ITBs, in late 2020 we decided it was time to make a major revision based upon customer feedback leading to the current V2 designation.  The original Sonic ITBs came with an CNC fuel rail that had AN6 fittings.  This required ordering additional parts and modification to the OEM fuel lines.  Additionally, the fuel rail required a fuel pressure regulator.

By Integrating with the OEM fuel rail vs including a new one, installation of the fuel system become plug and play.  This also reduced cost by 10% by not including a new fuel rail and fuel pressure regulator (some cost benefit offset by new brackets to support OEM fuel rail).

Another $300 to $500 cost savings can be realized as customers can reuse OEM fuel injectors with stock bottom cars.  The OEM injector can support HP gains made with ITBs and typical bolt-ons.  If customers compliment Sonic ITBs with Velocity headwork or Jerk cams, larger injectors maybe needed to keep up with the gains.  Halo Stroker kits will require larger injectors for sure.

Pricing

Sonic ITB V2

$2200

  • 52mm Oval CNC Custom ITBs
  • Custom velocity stack diameter based upon your application (Tell us about your set up and goals)
    • 55mm diameter velocity stacks for F20C
    • 60mm diameter velocity stacks for F22C
  • Supports OEM fuel rail for PnP compatibility, no fuel line modifications or additional fuel rail regulator needed
  • Can reuse stock injectors for stock bottom end cars (larger injectors needed for E85 or stroker motors)
  • 1/8” NPT taps for vacuum fittings on the throttles
  • Wabash TPS included

DBW actuator

$1100

  • Mounts under ITBs, not compatible with URGE designs vacuum block yet
  • Must use aftermarket ECU like AEM Infinity, Max ECU or Link (may require custom or aftermarket wire harness)
  • Is not compatible with flash pro

ready to order?

12 + 8 =

Options

  • Custom colors other than black or sliver $200
  • Vacuum Block V2.0 $395
    • Uses OEM MAP sensor
    • Currently not compatible with DBW actuator
  • ITG foam plenum foam filter kit $250

Found something you like or just shopping around?  Feel free to send us an email and a consultant will follow up to answer any questions you may have.

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