I'm thinking about changing to the 380 injectors before I get a ecu tune. What has been your experences with them on a stock head and the standard mods, 15%, cat-back, cai, etc. Worth doing and what gains did you get? Thanks for you input!

 

With mods described mainly a Piece of mind. The stock injectors can handle the load with no problem, but they are in the top range for them. The 380 put in more fuel than is needed but can be throttle back to be better to suited the car and later down the road when the injectors start to get dirty they will still supply plenty of fuel.

 

I concur as Dinan tunes their S2 performance package to 209hp (same as JCW w/380's) with stock injectors operating in their upper flow range.

That being said, would 380's give an optimal spray pattern in their lower flow range and still pass emissions testing? I would imagine fuel atomization would be better and ignition more complete at the higher pressures of the stock unit.

 

i just got some 380s from helix. the nozzle is longer; putting the fuel right on the back of the valves . i doubt the pressure changed with just a couple more holes. our pump should be up to it . the difference is very noticable.

 

Dinan may not use larger injectors but ...

 

How so and did you get a flash afterwards?

 

MINIAC: True, Dinan uses their own fuel pressure regulators, that is how they push the stock injectors into their upper range (working in tandem with their ECU reflash - higher fuel pressure + altered injector duty cycle = upper flow range).

Minimarks: He'll still pump more fuel with the 380 injectors even without a reflash.

Someone please correct me if I'm wrong; fuel pressure is kept constant within the fuel rail (down stream of the FPR) to the injectors. The injector size, rated by static flow capability (injectors rated at 380cc/m flows 380 cc's of fuel in one minute at 100% duty cycle with a set 43.5 psi of fuel pressure) determines how much fuel at a given duty cycle (usually no more the 80%) gets into the motor. The ECU doesn't know how big your injectors are, it just controls the duty cycle of whatever injector is in the system. A bigger injector with the stock duty cycle MAP will push more fuel into the motor (as long at the fuel pump and FPR can keep up). A reflash will optimize the duty cycle to the size of the injector.

 

well put .
i had a lean condition and this was a quick fix . it is still a tad lean up top. it gets a noticeable flat spot . so to be sure ; i'll get it dyno'd up at KTR in fitchburg , ma. (had to shout out) . they did the GIAC last year. so naxt summer it'll be down to LDG for a tune .