I heard someone on the board say that with a Walbro 255 pump you'll burn more gas than you would with the stock pump? How is this possible? The FPR should send all unused fuel back to the tank, right?

 

If you don't modifiy the fuel signal (with SAFC, etc.) then I think you migh use a little more gas (or a lot, I'm not an expert on this.) With a fuel computer you should be able to tune the fuel back to normal levels pretty easy I would think.
A better pump increases the fuel pressure which would push out more fuel in the time the injector is open because its not calibrated for it.

 

That makes sense...is the FPR vacuum operated or electronic? And also what is a rising rate FPR?

 

vac operated

 

sorry didnt want to start another thread. would i benefit (save more gave OR have more reliablity upgrading theses parts for my stock n/a s5 fc?

s5 tubo 2 or FD

fuel pump
fuel pressure
fuel regulator
injectors (most likely two more 550cc from another na for the smaller stock ones.)

its should be better then stock fuel system but im not looking for performance, just better gas and reliability. should i just stay na for this? thanks

 

The NA doesnt need more fuel, it needs less fuel. The stock computer currently runs very rich and as you will see with the S-AFC threads people can often lean out their NAs 20% cruise and 10% on hard acceleration.

For you to upgrade to these parts would be a waste of time/money/gas. You will have no reliability increase as detonation in an NA situation is much less detrimental and much less likely than in a forced induction situation. The reason why in a turbo this upgrade is helpful is when users substantially increase the boost they're running and therefore need more fuel.

 

The OEM regulater is vac opperated.

A rising rate FPR rases the fuel pressure in relation to boost that it sees via the vac nipple on it. typically is 1 to 1 like an Aeromotive FPR but some are adjustable for more fuel pressure per PSI like 3 to 1

 

so for better gas and reliability go for a super afc? I or II or VTEC? whats the best afc that best fits what i want to do? thanks