Is 255 lph high pressure the largest pump avail ?

David Neibert

SCCoA Admin
Lately I've seen that Ford is selling 80# high impedance injectors, but haven't heard much about fuel pumps. Is there a direct replacement pump that is larger than the 255 lph High pressure (Walbro GSS340) ?

For example, is the Focus 310 lph pump compatible with an SC ?

David
 
Well, as longs you could get the pump to work with the factory fuel pickup then I would say yes. If not, you would have to see if the fuel pickup could be modified to work. The other thing to take into consideration is whether or not our fuel lines are big enough to support that flow rating, and, what the flow@pressure rating is for the pump.
 
The newer gen cars are using a returnless fuel system, so if that pump is off a car like that, my guess is no. Ford uses Pulse width modulation to drive the fuel pump at full voltage but less than full duty cycle to maintain fuel pressure at the rail with the new returnless systems.

Note that for the return systems, there are machine shops that have made new fuel pump mounts and hats for the stang tanks that support 3 255lph fuel pumps.

Note I believe the lincoln Aviator pump will work in our cars and flows more than the 255lph high pressure pump. (271lph from what this post says:http://www.lincolnsofdistinction.org/vbulletin/showthread.php?t=26571&highlight=fuel+pump) He is using the Aviator pump in his Lincoln Mark VIII with a Vortec on it.
 
I would think it would be easy enough to make the hat work. Cut weld/epoxy and seal, though might be able to get them to make one for the SC, since I figure there are more SCs than 99+ Cobras. Is a billet piece really needed?
 
, there are machine shops that have made new fuel pump mounts and hats for the stang tanks that support 3 255lph fuel pumps.

Note I believe the lincoln Aviator pump will work in our cars and flows more than the 255lph high pressure pump. (271lph from what this post says:http://www.lincolnsofdistinction.org/vbulletin/showthread.php?t=26571&highlight=fuel+pump) He is using the Aviator pump in his Lincoln Mark VIII with a Vortec on it.

+1 on just doubling up the pumps. They(GSS340) are only $75 for Ford apps.
http://www.autoperformanceengineering.com/
Looks like the lincoln pump would only be worth the effort if it were free, not much of a gain there.
I have read that a 5/16 line found in most vehicles becomes restrictive some time after 400whp. One guy I know has used a pinch in the return line with success. You can run a bigger line, but you might as well just run a second stock line for all your efforts. Add to that a modified or custom fuel rail..

paul
 
Found a litte info on the Focus pump, sounds like a little modifying and it may work.

http://www.vmptuning.com/store/index.php?p=product&id=6&parent=21

Are these the 80's your referring too? http://www.racetronix.biz/itemdesc.asp?ic=FI114992&eq=&Tp=

David, don't you have dual 255's on your turbo car?

Yes, I do have dual high pressure 255's (in tank) on the turbo car. Thought about doing that, but don't really need that much capacity and it's going to be a lot more involved than just swapping the existing pump. Using the dual pumps also required remote mounting of the fill level sender/float and now the readings on the gas gauge are always a little screwy.

On my 91 I'm currently using a KB boost-a-pump, 6AN braided steel supply line, billet high flow fuel rails and a remoted mounted Aeromotive adjustable regulator plumbed with 6AN socketless hose. Return line is stock. If switching to duals I'll need a 2nd 6AN supply line, and a 6AN return line to handle the additional fuel flow. I would also need to re-plumb how fuel is being supplied to the rails.

If I could get another 15-20% of capacity from a larger pump, that should be plenty and won't require any other upgrades to my current fuel system, except for a fuel pump wiring upgrade. I'm just not sure the 310 lph focus pump will flow as much fuel as the 255 high pressure unit does above 60 psi. I'm still looking for some performance data on the Focus pump vs. the 255 High Pressure before deciding what to do.

David
 
Yes, I do have dual high pressure 255's (in tank) on the turbo car. Thought about doing that, but don't really need that much capacity and it's going to be a lot more involved than just swapping the existing pump. Using the dual pumps also required remote mounting of the fill level sender/float and now the readings on the gas gauge are always a little screwy.

On my 91 I'm currently using a KB boost-a-pump, 6AN braided steel supply line, billet high flow fuel rails and a remoted mounted Aeromotive adjustable regulator plumbed with 6AN socketless hose. Return line is stock. If switching to duals I'll need a 2nd 6AN supply line, and a 6AN return line to handle the additional fuel flow. I would also need to re-plumb how fuel is being supplied to the rails.

If I could get another 15-20% of capacity from a larger pump, that should be plenty and won't require any other upgrades to my current fuel system, except for a fuel pump wiring upgrade. I'm just not sure the 310 lph focus pump will flow as much fuel as the 255 high pressure unit does above 60 psi. I'm still looking for some performance data on the Focus pump vs. the 255 High Pressure before deciding what to do.

David

So Im assuming that you are maxed out in the fueling department? Or are we just forward thinking here?
 
So Im assuming that you are maxed out in the fueling department? Or are we just forward thinking here?

If it's not maxed out it's real close...Dave had to increase base pressure to 50 psi and set the Boost-a-pump to 20% voltage increase, to get injector duty cycle below 100%.

David
 
Thanks,

Scary stuff if you were near 100% duty cycle on those. Ford racing has released #80 pencil style injectors recently.
 
Thanks,

Scary stuff if you were near 100% duty cycle on those. Ford racing has released #80 pencil style injectors recently.

Yes..I knew about the injectors and having the high impedance 80s certianly makes things easier. I've pretty much decided on getting those injectors, now I need to decide what to do about the fuel pump.

I wonder if there is an inline booster pump that would do the job ?

David
 
You should be able to calculate your actual fuel flow necessary based on your settings during your tune. At your max RPM, how much fuel is that moving through your rail? then try and find a fuel pump that moves more than that at the pressure you need.
 
Only way I would want an A1000 was if it was mounted inside the fuel tank, and the only setup that I'm aware of that would work for an SC would be putting it inside a fuel cell. Feul cell isn't happening for this car.

I need something that will work with a stock late model fuel tank...even if I have to do dual 255s like we did on the turbo car.

David
 
Only way I would want an A1000 was if it was mounted inside the fuel tank, and the only setup that I'm aware of that would work for an SC would be putting it inside a fuel cell. Feul cell isn't happening for this car.

I need something that will work with a stock late model fuel tank...even if I have to do dual 255s like we did on the turbo car.

David

Are you talking for cooling reasons, noise reasons, or what David? Mounting it in the tank that is....
 
Are you talking for cooling reasons, noise reasons, or what David? Mounting it in the tank that is....

Mainly for space saving and noise reduction, but cooling would be nice too. Since the pump I've already got seems to be the highest capacity direct replacment pump anyone sells, I've pretty much decided to go ahead and convert to a dual pump setup similar to what I've got in the turbo car.

It's overkill but I know it works and I will have plenty of reserve capacity for when we get some good flowing aftermarket heads made.

David
 
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