Ok, I am putting in my new S5 street ported engine in tommorrow and am concerned about the pushing the factory injectors way past thier limit with the new ports. I am running a hybrid S5 turbo(only gonna push 10 to 12lbs), RB turboback exhaust, HUGE fuel pump, F-con with GCC, AEM wideband and much much more. The ECU system is a S4. The question I want to know is if I can put in 720cc for secondaries and still run the f-con. HKS says no but if I got this right, the impedence on the factory and 720's injectors are the same and the only difference is the amount expelled by the injector at "Static" so would the f-con perform the same? I know the f-con adjusts the fuel curve due to higher boost but if the resistance is the same no harm done right? I just blew my engine last Dec due to detenation, I dont want it to happen again, hurts the wallet!

 

Anyone??

 

I suggest put some 680cc from the gsl-se. They work great when i used them way back, when i used the F-con.

 

720's are fine with the F-con. Had it on my 87TII with a larger turbo and mild bridgeport. The only problems I ever encountered was boost creep due to the size of the ports vs the size of the turbo (to4e) but the fuel delivery was not a problem provided I could keep the boost at around 10psi (which was almost impossible).

Make sure you upgrade your fuel pump, and change out your fuel pressure regulator to an aftermarket.