what is the highest amount of boost i can run off the stock injectors and stock intercooler and if i had a aftermarket intercooler what is the safest amount of boost i can run with stock injectors

thank you
marcus

 

Still on stock ECU? Do you have a FCD?

 

yea stock ecu but i have a apexi safc im going to install before i up the boost just want to get some info first so i dont mess stuff up and yea i got a fcd

 

Without a fuel pump upgrade, I would recommend no more than 9 psi on a stock TII. The stock injectors can just barely support the stock turbo at max boost (~ 12 psi declining to 6-8 psi by redline), but the bigger problem is the fuel pump cannot keep up when fuel pressure increases above stock levels (stock S5 boost is 8 psi). Flow rate tanks, and you end up with a lean spot at peak torque (very bad). The simplest, and most crude setup to run the stock turbo up to higher boost levels is an SAFC + walbro fuel pump and a hefty amount of fuel added into the midrange.

 

thank you for the info i got a apexi safc 2 and a fpr so maybe it time for a upgraded fuel pump