More modern injectors definitely sound promising. On
witchhunter.com (a company that cleans and flow tests injectors), they describe various kinds of injector spray patterns:
- Wide or narrow spray
- Single stream or “V”-shaped (separate streams to spray into the individual intake ports of multi-valve engines)
- Straight or angled (so that the stream sprays toward the back of the intake valve even if the injector isn’t pointed straight at it)
And then any combination of the above, adjusting the angles so that the fuel sprays down the backs of the intake valves given the geometry of the cylinder head and how far away the injectors are installed. Another specification along which injectors vary is the electrical resistance or impedance they present to the engine management system.
If the OEM NSX injectors are simply wide, single stream injectors, that shouldn’t be too hard to improve upon. If the OEM NSX injectors have a “V”-shaped spray pattern and/or spray the stream at an angle to hit the intake valves dead-on, it might be more tricky.
Do you know what spray pattern and impedance the OEM injectors have and how the RDX injectors compare in those two areas?
Hi Greenberet,
I always like it when you chime in! It's always productive... =) Here is a lil more info and hopefully this can explain why the RDX injector idles well and makes more horsepower and torque over the factory injector and in theory should improve emissions and gas mileage! The pictures below belong to witch doctor and motoiq. Thanks!
OEM HONDA INJECTOR
The oem 240cc Honda injector is a peak and hold low impedance injector using a pintle style head.
"Pictured below is the earliest and the most common tapered pintle design that was used in most injector designs in the 70's thru the 80's. The pintle is tapered with a mushroom shaped tip causing the spray to diverge as it leaves the injector tip.
Note: the pintle cap was removed for this picture."- witchhunter.com
OEM RDX INJECTOR
The OEM RDX 410cc injector is a high impedance saturated injector.
"Due to the more demanding emission requirements thru the years, the injectors makers started putting more smaller holes to help atomize the fuel especially when the engine is first started. This one has four holes." -witchhunter.com
The RDX injector uses 12 holes that are vectored to help with atomization.
Here is the head of the RDX injector It's their newest DENSO injector pic belongs to motoiq.com the injector pictured is from a nissan but its identical.
Here is more info on the RDX injectors direct from the DENSO website
"One of the true innovators in electronic fuel injection technology, DENSO introduced the 12-hole injector in 1999. Its breakthrough design reduced fuel droplet size to 65 microns, providing superior atomization for improved engine efficiency. In 2002, DENSO followed with its UC injector, reducing droplet size even further, down to 50 microns – around one-half the width of a human hair. That same world-class engineering expertise goes into DENSO's entire line of First Time Fit® fuel injectors. Added-value materials and innovative features like welded seals allow DENSO injectors to meet the most rigorous emissions requirements in the world, including those for Super Ultra Low Emissions Vehicles (SULEV) and Partial Zero Emissions Vehicles (PZEV). A DENSO fuel injector is a precision instrument – they're that accurate.
While the electronic fuel injection systems in today's cars are incredibly sophisticated and can adapt to a wide range of conditions, their real-world performance often comes down to the accuracy and consistency of the injectors themselves. Each injector must deliver precisely the right quantity of fuel at exactly the right instant, thousands of times per minute, or performance, economy, and engine smoothness will suffer. The top parts distributors, retailers, and technicians won't settle for second-best on these crucial components. That's why they select DENSO First Time Fit© fuel injectors.
FEATURES
Premium internal components and welded-seal construction
DENSO fuel injector technology boasts the highest dynamic range
Calibrated impedance assures full system compatibility
BENEFITS
Maintains new-car smoothness and drivability
First Time Fit® saves valuable shop time
DENSO's injectors finer fuel spray significantly reduces exhaust emissions
"The injector atomizes a predetermined amount of fuel and delivers the fuel spray toward the intake valve based on signals from the Engine ECU. DENSO's injector generates finer fuel spray particles, significantly reducing the amount of hydrocarbon in the exhaust gas."
The RDX uses the newer UC injector
"UC 12 holes Fuel injection opening area gradually increases."
The image above from motoiq shows the vectored holes.
"Benefits and Features
Small fuel spray particles
The fuel flow to the fuel injection opening in the injector is improved – reducing the particle size of fuel spray (C60, UC).
The fuel injection opening area gradually increases, resulting in further reduced particle size of fuel spray (UC).
High responsiveness
Industry-leading fuel injection responsiveness due to improved magnetic circuit and lighter-weight valve.
Small size
Sealing by welding results in smaller injector size. (C60, UC)."
Heres an inside pic of the C60. This injector didn't have the vectored holes but is essentially the same injector besides the regular holes.
Give it time... In the next week or two there will be more NSX owners with this amazing mod.
