I was looking for a video, to see the difference in spray pattern and such for both the RX8 Yellow injectors vs either the 460cc injectors or the 550cc injectors. I haven't had any luck finding a video for the 460cc or 550cc injectors from the FC RX7 engine, but I have found one for the RX8 injectors. I have heard from Miata guys, which is where I came from, but no more since it's in car heaven, this is what I've heard:

Miata guys use FC RX7 injectors as an upgrade for turbo charging
Miata guys also found that RX8 injectors fit their cars
So this means that RX8 injectors fit the FC RX7, which really doesn't help the Turbo guys to much, but does mean a better replacement fuel injector for the NA RX7. Anyways here's the video for the RX8 injectors:

http://www.youtube.com/watch?v=PMw2o_PLHNM

 

better idle and MPG and smoother reving I believe is the difference .

but everythingI heard I heard from turbo charged miata guys as well

 

potential cost differences aside, if i were that dissatisfied with my Rx-7 injectors, i'd get Injector Dynamics units. i probably would not use Rx-8 units. however, when i go get my 8 out of storage (in 2 weeks, FINALLY), i'll try to remember to compare them to the Rx-7.

 

The ID injectors and the Rx-8 injectors are the same basic technology, hole-type injectors as opposed to the old pintle-type used by an FC

 

Yep, definitely good info, but still looking for a video that shows the spray pattern of the FC RX7 injectors for comparisons sake.