i am thinking about upgrading my injectors. my goal is to run somewhere between 280-300hp so i have to upgrade my injectors. i was thinking about upgrading both to 660cc or if i can maybe just upgrading the secondaries to like 800cc. but is upgrading all to 660cc too small and is just upgrading the secondaries only, a bad idea. what is the difference if i just go with larger secondaries???????

What ECU are you running? If you're running the stock ECU and you put in bigger primaries, your idle and low speed mixture will be way too rich. You've got to be able to tune for the larger injectors.

yeah just putting in like 680-720 secondaries is prolly just about right

i have an SAFC, so i don't need to upgrade the primaries, just upgrading the secondaries is good enough?????

550 primary and 680 secondaries is enough for 280 to 300 rwhp.



personally I would just leave them alone. Get a Walboro pump. Send you ECU to rtek and get it chipped.



That setup without any extra tuning is good for around 250 to 255 rwhp. Easier is always better. The last thing you want to do is have to start playing around with new fuel rails, new braided lines, new custom marren pulsation dampener and the works. That will be 10s of thousands versus a couple of hundred for new pump and ecu chip.

yeah all that stuff ends up being a huge pain in the ass.



rtek 4x720's is so simple....

well thats why i have the AFC, i am going to upgrade the injectors both to 660cc then tune it with that

So after 7 years of playing around with my car this is what I have before the original motor gave up.



SAFC wired to the Mazda pressure sensor

680cc GSL-SE injectors in the secondary fuel rail

10ohm resistors for getting the impedance of the injectors correct

Walboro Fuel pump

3" Turbo inlet duct

Racing Beat Turbo Back Exhaust

Paul Stokes DIY FCD with it wired after the safc so the voltage doesn't get clamped going into the safc



apexi AVCR for boost



What I noticed that if you use the SAFC to adjust for fuel by subtracting or adding you are also changing the timming. At 270 rwhp at 6000 rpm I recall my AFR being in the high 9s. I subtracted fuel from teh curve to get to 10s. When I subtracted the fuel I believed the timing actually advanced rather than retarded which is not what you want to do. This was at 11 psi(g).

oh wow so even at 11psi you pumped out 270???? i have a walbro 255 lph, racingbeat down pipe and fuel- cut controller.. but i thought that i would have to run at a higher boost like 13 or 14psi in order to get that kinda of power. hey do you have any pics of the resistors that you added, i have never seen what that looks like but i am aware that people do that in order to run low-imp injectors

here is a picture of a 10 ohm 10 watt resistor



http://www.electronicplus.com/images/products/10W-2.jpg



The boost was between 11 and 12 psi.



But be careful when you run that much. For me since I live in Canada early spring and late fall meant that the car overboosted because of the colder denser weather. I did not port my wastegate. I will be doing so when my car is reborn.



When it is reborn, I will remove the FCD, safc, and the 680cc inj and go back to 550cc hi imp and just get myself the rtek 1.7 for S5TII ecus. Port the wastegate and maybe even put the stock intake box back in.



I found the car most fun to drive when it was closer to stock.