vorsprung

I'm planning out a fuel system upgrade for my FD this spring and trying to decide on the best path forward. Been researching but haven't found much related to the stock twins.

Right now I'm still running the factory twins with a Power FC, bolt ons etc. But I'm pretty sure I will want to upgrade to BNR's or possibly go single turbo in a year or two.

I have a set of top feed rails, FPR, Pump etc. already. I was thinking of buying a set of ID1050cc (did ID stop producing 725's?) primary injectors and ID1700cc secondaries so that I will have the overhead for the higher power levels when I do the turbo upgrade. But I'm not sure if this be too much injector to be able to be tuned with the stock twins??

It would be nice to only upgrade the fuel system once and get rid of the 20yr old injector tech but not if it means sacrificing my idle/drivability etc. in the meantime.

BLUE TII

iTrader: (9)

If you go with the Bosch EV14 like the ID injectors you won't have to worry about "going too big" from what I have read.

People have reported that the 2200cc flowing ID 2000 can idle a 13B as primary injectors!

ID 1050 should give great driveability and fuel economy from what I have read (no experience).

scotty305

iTrader: (2)

I would recommend to contact your tuner or other people who are using the same ECU you plan to use, see if you can get good results with smaller top-feed primary injectors and larger secondary injectors.

My car was completely stock when I got it, eventually switched to a standalone ECU with stock injectors, ran that for a couple years then later installed ID1000's (before the ID850s or ID750s or ID2000s were available). I did the ID1000 install in a weird way, wanted to try a very simple setup with all the injectors in one fuel rail using an Xcessive lower intake manifold (and blocked off the primary fuel injector locations). This isn't an apples-to-apples comparison because moving the injectors further is generally bad for idle smoothness and transient throttle response. It would probably be fine for a track-only car that gets trailered to events. My car isn't a daily driver anymore, but I prefer a car that is tame enough that a non-enthusiast could drive it and not complain that the idle is funny or the throttle response feels weird. I added very small (300cc/min) top-feed injectors using Full Function Engineering primary rail, and the idle and drivability is nicer than it ever was even on the stock ECU and injectors.

DaleClark

iTrader: (55)

I haven't fully tried it yet, but Rotary Performance has a secondary fuel rail that uses 2000cc injectors and the stock FPR. Bolts up to the stock primary rail. I have a review of it in another thread.

That's a nice inexpensive way to get more fuel headroom for the stock twins and BNR's. This would probably handle a mild single turbo just fine as well.

You can spend crazy money on the fuel system. Big thing here is to find a happy medium - many guys don't need the capacity or flexibility of a really huge fuel system. I'm for spending money wisely on an FD, not wasting it.

Used to be able to drop in 1300cc secondaries and you were good, but as time goes on that becomes way more of a problem. They are bored out 850cc injectors and when you start with 20 year old injectors you can run into problems like locking open or closed. That can cost a motor.

Dale

IRPerformance

iTrader: (41)

You will have no issues with a 725/2000cc of 1050/1700cc combo if tuned by a competent tuner. The new injectors are light years ahead of old technology and can be controlled much more precisely.