they have different style of injectors completely from what I remember, this again I am not sure and I could be wrong, but you may want to check into it. you may as well go with either 4 gsl-se injectors or a set of 4 720's or 550-1200+cc/min combo. but fuel pressure plays a big role in how injectors work. Like I said, get an adjustable fpr and up the pressure, better atomization and higher flow all around will lessen the use of the pwm on either set. Just a thought though. I may have to do a little research on those 850 secondaries of the fd. I remember seeing a picture and they look very different from the normal topfeed style denso injectors. I dunno, it was a smaller picture so I don't completely know for sure if that is right. though you don't hear of many people (none that I have heard of)using them in an fc intake manifold.

dpf22

 

ok so im thinkin about getting my MS this weekend.....what do you guys have? and what would you suggest i get? set up will be 550 P's and 720 S's or 4 720's and FD twin turbos running 8-12 psi tops one a 1st gen SE 13b? (sry for jacking this thread)

 

I think you should be fine with 4 720's. Try to lean towards getting an adjustable fuel pressure regulator. As stated earlier, when you have more pressure, they will run with less pulsewidth all around and also you will have less problems with atomization, thus less stumble issues from sloppy injection.

dpf22

 

4 x 720 or 4 gsl-se is the same thing. Remember unless you switch to an adjustable fuel pressure regulator any injector you use will flow less than what its rated at due to mazda's lower fuel pressure. That said, every engine is different and you won't know what works best until you have it running. The thing about injectors is if you have too much you can always cut back on your VE table, if you don't have enough... well thats another story. I'd lean towards 4 x 720. And as dpf22 stated FD injectors will not work with FC rails as they are totally different.

 

im planning on getting an adjustable FPR. MS I 2.2 is what im thinkin?

 

rolfs_7 you should start your own thread.

 

yeah well no point really now....

 

WEE!! my own thread. i dont mind sharing