too much boost?

[talon_frost]

just a quick question....if running 16psi on stock fuel pump with out rewire,what would the car do??on a 1g talon

 

[cruisintalonawd]

detonation if your doing to for to long

 

[1992awdlaser]

You will probably hit fuel cut running 16psi on a completely stock car (I did). I wouldn't take the chance of running it on a stock car though. Why is it that you don't want to upgrade the pump? Its only $90 and takes half an hour to install.

 

[disciplekyst]

I was asking myself the same question,
would just putting a 190 lph pump would do the trick, or am I obligated to rewire it to make it totally safe??

 

[1992awdlaser]

My pump is not rewired and my car runs just fine, for now. I am going to rewire it when I put in a different pump or when I put a bigger turbo on, whichever comes first.

 

[Mr Peepers]

More boost means more air, and more air needs more fuel to maintain a safe air fuel ratio. The stock fuel pump can only flow so much fuel, and having less voltage at the pump decreases its output even more. Rewiring the fuel pump sends all the voltage possible to the fuel pump, optimizing its flow.

Not only that, but you have a 1:1 rising rate fuel pressure regulator, meaning that for each psi of boost, fuel pressure is increased by 1 psi. This is required to "overcome" the pressure/boost in the intake pushing back on the injectors and inject the same amount of calculated fuel. Like stated before, the fuel pump can only flow so much, and even less at a higher psi.

More boost=more fuel required AND the more fuel pressure to compensate for the increased boost pressure.

I think there was something a while back saying how a rewired stock fuel pump outflowed or nearly outflowed an upgraded one without being rewired, I could be wrong. I see no reason not to rewire it while you're back there. I just rewired one about a week ago and was amazed at how much more fuel I had to play with while tuning.

 

[1992awdlaser]

Another problem with not rewiring the pump is at higher rpm the voltage to the pump will drop even more. My injectors allow me to not need it rewired since they are so much bigger then needed and I just tune with dsmlink. I didn't rewire mine when I changed it because I didn't know anything at all about wiring back then. I still don't know exactly how to rewire it, but I can figure it out with one of the tech articles or v-faq and be confident that I did it right. Back then I wasn't confident enough to mess with the wiring.

 

[Epic904]

Eclipse Fuel Pump Tech Tips Here is one article on fuel pump rewires.