What secondaries to run?
 

Going with a 720cc on the secondaries ... do they make drop in high impedence ones yet? Or are they all low impedence that require resistors?

Who do I go with? Denso, Greddy, Bosch ?

Greddy injectors are just Denso sold under a different name. They're all going to be low impedance, so source some 6-10 ohm, 10-20 watt resistors to go with them. I don't think Bosch makes 720cc injectors; I just know they make the 1600cc injectors that are popular on high HP builds.

Injector dynamics makes some 725cc high impedance injectors that are really nice and are based off a much newer injector design with adapters.

I just put a set in my primaries and a set of their 2200cc High Impedance injectors in my secondaries.

http://www.injectordynamics.com/

if you go with them make sure you ask for 11mm/60mm upper adapters and denso lower cushions. They should know what FCs run now because I just worked with them on mine.

http://www.injectordynamics.com/ID725-60-11.jpg

Will these fit the stock manifold and fuel rail without modification?

It'll definitely fit in the rail, as for the manifold I'm not sure if it will seal properly to prevent a vacuum leak. The factory injectors use a lower grommet, not an o-ring.

They sell it with a denso style lower grommet as well. it's the same size as the stock grommets.

Thank you Eage8.

Just installed a set of RC Engineering (www.rceng.com) 750cc injectors in the secondaries of my S5. In conjunction with a BNR Stage 1 hybrid, a Supra TT fuel pump and tuning with an S-AFC II, the best dyno run was 267 whp and 230 ft-lbs at ~9psi and 11+ AFR.

Their high impedence units are referred to as "Saturated".

From the FAQ on their web site:
"Do I need high or low resistance injectors for my application?

Injectors are classified into two categories.
1. High impedance/resistance (saturated) 12-16 Ohms.
2. Low impedance/resistance (peak & hold) 0.5-6 Ohms.

Saturated injectors require roughly 1-1.5 amps to open the injector. Peak & hold injectors initially needs about 4-6 amps, and once open drops to roughly 2-3 amps to keep it open. ECU design will dictate the use of one or the other. Most late model cars will use saturated injectors."

thanks for that dyno sheet, was looking at bnr turbos and was wondering where boost started.

wanted to keep it close to stock :)

Here is my BNR Stage2

it has the boost on it, though it's kind of bouncy, make sure you look at the scale :p:

http://userpages.umbc.edu/%7Emigol1/...Dynoresize.jpg

so rx 750 saturated injectors it is.

I think it all depends on what ecu you are running as well.

If I could do it all over again, I'd get the rx7store kit sans injectors, order 2 1000cc ID, and grab a sprint re. Done.

edit: I'm running 1600cc's modded to fit the stock rail, fwiw.

Don't forget to upgrade the fuel pump to at least a 3rd gen pump or better yet, a Supra TT pump. The latter pump should be good for any future upgrades you may install.

Here's what I'm running:

BNR Stage 4
Microtech LT-10S with X4 box
Z32 TT Fuel Pump

Plan on pushing 375+. So I'd think the 720's should do it? I really don't want to upgrade the rails and what not, was just looking for a plug and play solution.

4x720s won't handle 375+

with 1680cc pro-import injectors from injector.com you won't have to modify the rail. or 2200cc injectors I posted earlier.

guess ill need the 1680s :)