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Injector Dynamics Fuel Injectors

Injector Dynamics have become the injector of choice for professional tuners everywhere. Their injectors provide superior atomization and spray patterns. Each set is matched to within +/- 1% across the useable dynamic range of the injector. This allows for more precise low pulse-width tuning by not having to compensate for large flow deviations from cylinder to cylinder. The result is smoother idle and better efficiency. Injectors other than ID2000 require modifying original wiring harness with the supplied terminals and connector housings or the purchase of plug-and-play adapters.

Injectors sold in sets of 4.

Usually ships within 2 to 3 days

Manufacturer: Injector Dynamics

Applications:

  • Subaru Impreza WRX MY2002-2014
  • Subaru Impreza STI MY2007-2014
  • Subaru WRX STI MY2015-2017
  • Subaru Legacy GT MY2007-2012
  • Subaru Outback XT MY2007-2012
  • Subaru Forester XT MY2006-2013

What makes these injectors superior to other injector options? In short, dynamic injector characterization and matching. Injector flow rates from one injector to another will vary, sometimes signficantly, across the dynamic range of the injector. Injectors that are matched strictly by their static flow rates are ignoring the possibility of large deviations in flow when operating at smaller pulse widths. Injector Dynamics data shows as much as a 13% spread at 2msec compared to a 2% spread at static flow. Matching the injectors dynamically across the range of useable pulsewidths results in more accurate fuel delivery to all cylinders which allows the tuning to be more fully optimized.

How do I determine what injector size I need? A rough approximation of an engine's fuel requirements can be determined based on the horsepower. Start with a realistic approximation of the expected power output (crankshaft HP). Multiply HP by 0.5 for normally aspirated engines or 0.6 for turbo engines. If running E85 use 0.65 for normally aspirated and 0.77 for turbo. This multiplier is an approximation of the brake specific fuel consumption and its entirely possible the actual number may be different depending on the efficiency of the engine but these numbers will get you in the ballpark. Take the resulting number and divide by the number of injectors multiplied by 0.80 (or maximum duty cycle). This will give the injector flow requirements in lbs/hr. To convert to cc/min multiply by 10.5. For example, a turbocharged 4 cylinder engine (with 4 injectors) running E85 and producing 600bhp would look as follows: (600 x 0.77)/(4 x 0.8) = 144.38 lbs/hr x 10.5 = 1516cc/min. Therefore a ID1700 would be the best option.

Can I raise the base fuel pressure in order to run a smaller injector? Raising the fuel pressure will increase the flow through the injectors. The percentage increase in flow will be equal to the square root of the new pressure divided by the old pressure. For example, increasing fuel pressure from 43.5psi to 50psi will increase flow through 1000cc injectors to 1072cc.

Will idle quality and drivability be compromised with a larger injector? Injector dynamics injectors, due to their dynamic characterization and matching process together with the accurate tuning data that is readily available yields a very stable idle on injectors up to 1000cc. Injectors larger than 1000cc will tend to suffer some loss in idle quality and drivability. ID2000 injectors can be extremley difficult to tune with pump gas such as E10 due to the very small injector openings required at idle as well some loss in atomization quality with these larger injectors. Raising fuel pressure and/or targeting a rich mixture at idle can provide some improvement.