hey guys, i have a stock t2 s4 engine. wondering what type of injectors (high or low imp?) should i change if i want about 250-280 hp? I am running everything stock except for dual RB exhaust.

 

720cc secondaries (almost all are low imp., if you need high imp. add resistors)
Rtek 1.7
Bigger fuel pump
Boost controller @ 10+ psi

 

do a search on the injector issue, it depends on the production date

 

Under 87.5 they're low imp, anything above is high imp. Get an rtek 2.1 instead of 1.7, way better.

 

How much boost can S4s hanble, considering the engine has about 90k on it.

 

A better question is 'how much boost can the stock turbo handle?' The answer is about 12psi before you start reducing the life of the bearings. Note that this is only with supporting fuel mods. Upgrading the turbo can lead to lead to higher pressure operating ranges.

 

820cc secondary injectors S4' are low imp a full exhaust FMIC 12psi walboro 255 with FPR a computer to control it. One step down is 720cc with an Rtek

 

if you search youll get like 30whp .. 4real

 

So why is the question about the turbo. Wouldn't you be concerned about the seals of the engine first?

 

y do people keep sayin s4's are low impedance...like the guy said a little ways up in late 87 they changed to high impedance....wat year is your car??

 

That is true 87.5 check for the resistor pack in the front.