Ok, I'm trying to figure out what size injectors I should run and how many. From threads that I have read, it's either 4x550cc or 2x720cc.

What I have:
S5 6-port
Half-bridged
N/A, obviously
Haltech PS1K
Tweakit ITB with option of running 2 injectors or 4 injectors

My car is in no way a daily-driver so the whole streetability is not that big of a deal. From what I have gathered 4 injectors are better for idling and low speed driving because they can be staged and 2 injectors are easier to set up.

Any insight would be appreciated.

 

I can only comment on the 4x550cc as I use them. I havent had any problems, seem to do the job well. I don't bother staging them but even with a full bridgeport its pretty tame and driveable down low. But I doubt you would have much trouble with the 720cc ones. You could just go for whatever suits you better.

 

yeah either injector combo will work.

in the R26B sae paper mazda did some testing and they found that placing the injectors really close to the engine had no effect on power, but helped mileage and response.

so in theory 4x550, with 2 injectors in the stock primary spot are a little better. since you have a side port engine and not a Peripheral with GIANT intake ports, it may not be noticeable...

 

I did run 4 550's and now run 2 880's in my HBP 13b, So eaither will work fine, I havn't noticed a difference but i dont daily drive my car and i dont drive it around town or city's.

 

wish to know this too...

Want to run 460cc prm, 4 550cc on ITB.... prm to 3500-4000, 2 550cc at 4100 to 6500, 2 550cc at 6600 to redline .

IS this possible?better atomization?

 

Yeah, I kinda figured it would come down to whatever works best for me, it's just good to have an idea of what others use for an idea of what to start with.