Sketch_hs

Anyone know the lph of the stock turboII fuel pump? How much power is it good for?

Spirit-RE

iTrader: (25)

Not good for anything over stock

Sketch_hs

any real data?

2slow4stock

iTrader: (18)

Just buy a FD fuel pump, it pushes more than 255lph. I can tell you that the stock TII fuel pumps are (guessing) 200ishlph.

RotaryRocket88

iTrader: (7)

This is the only data I've every found: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/measured-flow-stock-tii-pump-524944/#post9154530

It includes flow data for the NA fuel pumps too. You'll see pretty quickly that over ~3.5 bar (51psi), the stock TII pump is struggling.

Also note that a walbro's 255LPH claim is at low pressure and 13.5V. Pump voltage in car will only be 12V.

Sketch_hs

ummm vehicle voltage when the car is running is ~14v

Spirit-RE

iTrader: (25)

yes but only 12v gets to the pump.

ifryrice

Fix your wiring

FelixIsGod29X

iTrader: (50)

If you need a pump i have a complete drop in walbro. PM me if interested.

RotaryRocket88

iTrader: (7)

If measured at the alternator or battery, sure. Break out the multimeter and test for yourself. You're not getting 14V at the pump.

Oh, and you're welcome for the info .

ifryrice

13.9, last time I checked which was about 3 hours ago. Alt was @ 14.1. There's not much reason why you should be expecting such a dramatic drop except for old wiring.

RotaryRocket88

iTrader: (7)

Small gauge wire, long wire length, the ignition switch, 3 relays (main, circuit opening & fuel pump resistor/relay) and other electrical loads all combine to drop the voltage at the pump. Old wires can certainly play a role, but it is by far not the only reason. If you really measured 13.9V at the pump, your system has likely been rewired to bypass a relay or two and/or has larger wiring. Of course at WOT, this value will drop even more, so whatever you measure in the driveway is of little importance.

Consult S4 FSM page 4B-72. Pump voltage spec is "approx 12V" with the engine running, not "approx 14V."

Regardless, this really doesn't matter much and is getting off-topic. The flow data speaks for itself when it comes to comparing the stock fuel pumps to aftermarket choices.

ifryrice

It's stock, haven't gotten around to rewiring as it's still on the stock pump and the voltage isn't terrible. I don't have any drop during WOT either (@ pump). Only additional load at the time was running lights, though I don't see much significant drop with radio/blower on either for that matter. All contacts/relays/etc have been cleaned up as well as the pump connections as well.

It would make sense for the FSM to describe a '12v' system as 'approx' 12v rather than describing it's charging voltage.

Sketch_hs

Looks like the stock turboII pump should be able to handle 300whp no problem

Sketch_hs

I got my fuel pump wired with a nice thick gauge wire to ignition on voltage 14v at pump should help

BotieRacing954

i have a s5 turbo II and I have the walbro255 runing 14v and it works like a champ