Stock Injectors + Boost Pressure

ModMX3 - (Carmaster2005) · May 3rd, 2006, 3:30 pm

Dose anyone know how much boost the b6 dohc stock fuel injectors can handle ? I wanna run 12 psi, If not what kind of injectors would be best ? thanks !

oh-hell · Post by **oh-hell** » June 3rd, 2006, 11:18 pm

ask rebel he has moded rails with injectors for sale.

Steeb · Post by **Steeb** » June 7th, 2006, 7:11 pm

12 psi on what size turbo?

im still a noob to forced induction but doesnt injector sizing also have to do with power levels and turbo sizing?

while running the stock injectors on a t3 at 12psi may be safe and running 12 psi on a gt40 probably isnt. factors like heat and turbine/compressor efficiency come in to play.

be more specific on what turbo setup you have and if you are going to use an intercooler or not.

JWMotorsports · Post by **JWMotorsports** » June 7th, 2006, 10:21 pm

It depends on both the size of the turbo and the amount of fuel control you have. I'd recommend bigger injectors period. You can get away with a FMU on small boost but I personally don't like that method at all, is worse than dowsing your fingers with fire gel and then playing with strike any where matches for most people new to tuning. You'd have to calculate the amount of HP you need to support on that turbo at "x" boost. Then you'ld have to vist http://www.rceng.com and use their injector calculator by inputting your injector size and target HP. Play with the fuel pressure input field to find out how much fuel pressure you need to support that HP level at .65 Break Fuel Consumption and no more than 80% duty cycle. Then subtract that fuel pressure from your base line fuel pressure and divide the differance by the "x" boost pressure you used to calculate your HP goal. That will give you the rising rate needed per pound of boost to flow enough fuel. You'll also need atleast a Super-AFC and tune the car with a wideband AFR setup. I'd also recommend a Wahlbro 255 Hi pressure fuel pump.

ModMX3 - (Carmaster2005) · June 8th, 2006, 5:46 am

Im using a vj-11 turbo on a b6 dohc motor, I belive it maxes out around 15 psi and i think its CFM is around 190, not that much. I know smaller turbos produce more heat . im using a mr2 intercooler and 230 cc injectors. im think now of only running around 8 - 9 PSI max on this setup after doing more reading. at some poing i will get a SAFC 2 so i can upgrade to the 310 cc injectors i have.

rebel2k4 · Post by **rebel2k4** » June 8th, 2006, 7:38 pm

I have some denso top feed 310cc mx6 gt injectors if you are interested. they will bolt directly into the b6/bp rail.

Josh · Post by **Josh** » June 9th, 2006, 1:29 pm

rebel2k4 wrote:I have some denso top feed 310cc mx6 gt injectors if you are interested. they will bolt directly into the b6/bp rail.

thies are the ones you want. dont run stock injectors. they are way too small. they cant even provide enough fuel for 5psi on a JV14 turbo.

ModMX3 - (Carmaster2005) · June 9th, 2006, 4:18 pm

Yeah i actually have 310 cc probe injectors and at one time had them installed, didnt run right because i dont have any kind of fuel control device. Right now im rinning the BP injectors with the FMU and ive ran up to 9 psi so far & never had a problem so far although im sure im prob maxing them out. my first priorty is to get a stronger clutch to hold this power now. it starts slipping around 5 psi + especally in 2nd & 3rd. Turbo's are so much Fun !