What LPH or GPH is the stock rating for an 01?

 

I've never seen it rated that way .... but I'd have to guess a minimum of about 25 gallons per hour.

 

I believe its 225 lph but not certain.

 

That would be (roughly) 56 GpH .... wow .... more than I thought ....

But that actually kinda makes sense ... I was calculating what the engine would burn (SWAG) in an hour .... but the pump needs to deliver more to keep the line pressurised, and also if the pump is working at max capacity for say an hour, probably likely to burn it out .... a bigger delivery than required would allow the pump to run in a more reliable manner.

 

Stephen...I have a Racetronix Hotwire and i am trying to figure out if its worth the upgrade to the LPE/Racetronix pump or if there is really any difference between the two. Thoughts?

 

Still looking .... but try this ...

http://www.lingenfelter.com/pdf/c5fu...structions.pdf (rated at 225 LpH, 60 GpH)

I'm pretty sure the "stock" pump is made by Walbro .....

http://www.autoperformanceengineering.com/

On the left of the page click on EXTERNAL and scroll down ... I'll bet our stock pump is either the GSL391 and if you click on the flowchart you'll see that at about 60 PSI it pumps about 40 GpH .... again I'd bet that is, or is close to, the stock pump.

 

The Racetronix C5-FPA is the Walbro/LPE GRJ420.
http://www.racetronix.com/RX-C5-FPK-2.html
It is the only true C5 direct-fit HP pump option.


The factory C5 pump is similar to a GSS242 in performance.
It all comes down to the armature and gear set used:

http://www.racetronix.com/307vs340.html

 

So do you actually know how much the STOCK fuel pump puts out?

 

I have still yet been able to get that answered so as of now, no...i have no clue.

 

I don't have the stock flow at home but I will try to get some of that test data and post it in the next day or so. I will be sure to post it in multiple different units of flow (lph, gph etc.).

On the statement about the pump working at maximum capacity for an hour and burning out, that is a common misconception and isn't the case. Your pump is always running at maximum capacity - it is a constant volume flow system. Keep in mind the fuel pumps in roughly 95% of the vehicles on the road are always working at maximum capacity/constant flow. The pump doesn't care or know if the flow is almost all being returned to the tank (idle and light load conditions) or nearly all of it is going to the engine and very little is being returned to the tank (full power).

The reason I said 95% is that a few vehicles use variable flow fuel pump systems. The simple ones used in some vehicles simply reduce the voltage to the pump (often with a resistor) at idle or light load conditions. This reduces the pump speed and reduces the amount of electrical load from the pump and reduces the noise that the pump makes. This system was/is used on some Japanese vehicles and on some GM vehicles (supercharged 3800 V6 for example).

Some newer vehicles actually pulse width modulate the fuel pump speed in response to or in expectation of the engines demand so that the pump is only producing a little more than needed or exactly what is needed (in the case of the vehicles that pulse width module the pump to maintain fuel pressure and don't have a traditional fuel pressure regulator).

In the C5 and C6 Corvette and most common fuel pump systems, the only thing that changes the load on the pump is increasing the fuel pressure. Then the pump will flow less fuel and take more current to do so because it is doing more work (with work defined and pressure and flow).

The pump needs to make more flow than the engine requires in order for you to maintain fuel pressure.

In the C5 and C6 Corvettes it also needs to make more flow than the engine because the pump is running two jet pumps (or venturi pumps). Jet pumps consume a little bit of the fuel pump flow and use the low volume/high pressure flow to induce a high volume/low pressure flow.

One jet pump keeps the canister full of fuel (the pump actually pumps fuel from the canister, not from the tank itself). The other jet is used to transfer fuel from the passenger tank to the driver side tank.

You also want to have a little extra safety factor to handle hot fuel handling because as the fuel gets warmer the amount of fuel vapor created internally by the pump increases and the amount of actual flow of the pump reduces. All since the fuel expands in volume (becomes less dense) you actually loose mass flow of the pump as the fuel gets hotter. We normally try to leave 10% extra capacity to account for hot fuel handling. Some pump designs are better than others in terms of hot fuel handling. The TI/Walbro gerotor style pump tends to work better with hot fuel than some of the turbine style pumps (including some of the turbine pumps from TI/Walbro).

The factory 1997-2003 C5 pump is a gerotor pump produced by TI/Walbro. Our high flow replacement pump is also made by TI/Walbro.

The 2003.5-2004 C5 and the 2005-2008 C6 fuel pump (same pump/same fuel system) is also made by TI/Walbro but is a turbine style pump.

 

very good info jason.....I do have a question though.

Why dont Walbro make a single replacement pump rather than charging us for a new canister and all. Im not gripping....Just curious

 

b/c the canister is almost impossible to get apart. Most of them are old and very brittle now. The inlet checkvalve is also slightly larger.