if you have a new fuel rail and bigger injectors could that cause your car to run rich because of the larger fuel flow?

 

If you are running the stock ECU with no way of managing the fueling, it will. You will need some sort of engine management to control the larger fuel injectors.

A fuel rail won't do shit. It is only for bling unless you are pushing 700 hp to the wheels.

 

alright so could you use an fmu to contol the fuel flow?

 

So fuel rails are completely useless?

 

I don't really have much knowledge about FMU's, but I think that they are only for boost applications as they will add fuel pressure as boost pressure increases. For example, a 12:1 FMU will increase fuel pressure 12 psi per pound of boost ran.

Yes. Unless you have a 700 hp beast, you don't need one. The stock fuel rail can handle 650 hp easily.