Last year i had witchhunter do the cleaning /rebuild and flow tested them to 2% of each other and my recent upgrade to the mustang injector was a better and more noticeable increase. nothing on paper, but it is smoother and especially idle. Torque seems very constant now, but that is all butt dyno :-)
not much on flow design but if you look at the stock setup, it seems that the automized fuel could re-group together before even leaving the long nozzel of the injector. the pintle is deep withing the nozzel. On the mustang injector the pintels are right at the end.
In the same time i wondered the same thing as you. the new injector will stick into the head farther than the stock one, as seen in the pictures of length.
i have a 1993 e36 m42 and my old injectors were stock 4 pintles. I did not know that until after i swapped them in and looked closely.
was it worth it? i am not 100% sure. But i will test the claim on MPG's going up on this next tank of fuel. If no power increase, a better automized and better burning fuel consumption should lead to less fuel consumption in the end. and thats worth it to me.
I will report back on mpgs
here are the pictures to compare that i didn't get around to posting, from the install.
BOSCH 0280150556 Multi-Port Injector


