Fuel pump voltage

[nelsmar]

Has anyone tested the stock fuel pump voltage? I am wondering if there is a drop from battery voltage or not. I know @Dustin@Dynosty did a lot of testing on the limits of the OEM pump, any chance voltage was verified? I am trying to see if it might be worth running power direct to the battery to get a little more flow out of the pump as our canister is a tad cramped to be installing say an aero 340 pump.

Also if anyone has pump flow charts at alternate voltages that would be superb! I was considering just using a boost-a-pump rather than trying to heavily modify the OEM carriage, or having to use a surge setup just to get a larger pump in. A boost-a-pump or direct wire is far cheaper than some alternatives that are currently on the market for higher horsepower levels.

Just for reference I personally am using a DW65C pump, and I think I'm going to be wanting just barely more than this pump will push out on E85, not enough to warrant $1000-$2000 fuel supply upgrades.

[6speed_Sam]

I wouldn't worry about the voltage drop unless you get to the limits of what it can do.

I did run a dedicated larger wire to my fuel pump(walbro) in my s/c grand prix because I had everything (boost, fuel injectors, etc) at their limits before I had to upgrade things again.

[Ross]

What are your power goals?

[continuecrushing]

hmmm...in for more info

I remember now on my Srt-4 a fuel pump rewire(with relay) was a popular/needed mod when running more boost.

[troek]

popular on r32s as well as it had a resistor in the line that would cut fuel pressure while idling to prevent fuel from needlessly cycling through the engine bay. it didnt always work and would short you on the voltage. is that realy a problem on a car as new as this?

[nelsmar]

Originally Posted by Ross

What are your power goals?

400-550whp on e85. Which surpasses the flow ability of a dw65c by a fair margin at 12v. The reason I am asking is I know I will be pushing till my pump maxed out at current. I figured since I will be looking into this I would make a thread (as I couldn't find one) so that way if I end up with information or someone else does it can be easily searchable

Mind you im dropping the compression a bit to increase my power on pump gas as well. So my manifold pressure will be higher than the guys on the stock internals pushing these power levels. This will require more PSI manifold pressure to compensate for decreased compression ratio to obtain the same power. One tuner i spoke to started leaning out near the 500WHP mark on the I believe it was the larger walbro pump (sometimes called the walbro 400LPH, or 430LPH). As I will be pushing a tad more manifold pressure to make the same power level this would 'shift' the pumps efficiency range to a less efficient range. These small pumps can do wonders on N/A cars for high power but E85 + higher boost they start to fall off a lot.

[nelsmar]

Originally Posted by troek

popular on r32s as well as it had a resistor in the line that would cut fuel pressure while idling to prevent fuel from needlessly cycling through the engine bay. it didnt always work and would short you on the voltage. is that realy a problem on a car as new as this?

Some cars are simply regulated. Iirc our cars Ecu can request pump duty cycle. So I don't know if this is pwm, raw voltage, or some other method for duty. So somewhere there is logic for our pump and for all I know it's based on 12v logic with a voltage cap.

[srt4_night_rider]

Originally Posted by Shutter

hmmm...in for more info

I remember now on my Srt-4 a fuel pump rewire(with relay) was a popular/needed mod when running more boost.

Had to do it to my srt-4 as well, there would be a drop in the fuel pressure up top if you didn't rewire it.

[s2d4]

This page has what you are after
http://*************/forums/f34/frs-f...kthrough-1179/

btw, it also shows the fallacy in 1000cc injectors kits and run it at like 15% for some idiotic reason.

[nelsmar]

Originally Posted by s2d4

This page has what you are after
http://*************/forums/f34/frs-f...kthrough-1179/

btw, it also shows the fallacy in 1000cc injectors kits and run it at like 15% for some idiotic reason.

Almost nothing related to what I am talking about in this thread, although it is a great post. I am looking for the voltage supplied to the OEM pump by our car, not on a test bench. My car is currently in storage and I won't have time to do any testing for a number of weeks on the voltage that the car is supplying to the fuel system. going from 12v to 13.5v can give a nice bump in fuel flow.