Other than a poor performance to cost ratio are their any negitives to a minor increase in flow of the 550 cc injectors. A number of people replaced with 850 cc injectors but have idle issues, I was thinking of having RC bore out to a much more conservative 600 to 650 flow rate. By the way I use a Power FC and have 1220 cc injectors in Secondary positions.

 

I would change the secondary injectors to 1300's if you only need a small increase.

 

why do you need more fuel? If you are on stock turbos 550/1220 should be fine. If you have a single turbo you might as well just get an aftermarket rail, FPR, and 1680's

 

Don't want to go to limit of 1300 on secondaries. Going to BNR's

 

I have 850/1600 and have no problems idling at all.

 

RC charged $175 per injector to open them up. My 850cc -1680 set up starts and idles perfect ,The fpr is set at 40 psi with no vacuum .I get $5 to mill the rail . Why pay $ 175 x 2 when 850 s will idle well if set correctly .

 

^^ the AEM EMS does not have some of the [fixable] difficulties of the Power FC with larger primary injectors