hey, i have been thinking of a way to use a surge tank with my stock fuel tank, the toughest aspect has been the second external pump that would send fuel to the filter/rail. so then i thought about about how an accusump oil system works and it seems this would be ideal for this fuel application.

by connecting accusump inline between the fuel filter on the firewall and the fuel rail at the intake manifold, with check valve between filter and accusump, you could prevent drops in fuel pressure.

it wouldnt even need a valve/switch to open and close the accusump(like with the oil setup), the in-tank fuel pump pressurizes the whole system before startup, and turns itself off when the car is shut down. so the whole system would be mechanical and require no matenience.

can anyone think of limitations to this setup besides racing class/series rules?

 

I don't know if it would work as envisioned but this is a great example of thinking laterally on this question. Good on ya, for the idea.

K

 

For some reason, I seem to remember someone posting something here, within the last year about doing this, and they didn't have any problems at all. You do need that extra external pump, though, to keep the surge tank pressurized. Have you searched through the archives?

Edit: Aha, I just found the link to the website that was talking about it. It was from late last year. Check it out and see if it will do what you were thinking:

http://toyotaperformance.com/surge_tank.htm

Let us know how it goes.

 

thanks for the great link. that was the original system i was going to try, but space is limited, and usually that surge tank would have to be in-car.

the beauty of the accusump is that the air pressure held within the piston is what substitues the second fuel pump for a surgetank setup, this accusump is all self contained. the fuel pump in the tank is what would pressurize the system. and the 2 liter unit is only 12x4" so i could place it in the engine bay next to the fuel filter. plus you dont need to rerout the return line, ths goes inline with the main line going from the filter to the rail.

anyway, i should be able to do this within a few weeks and ill let you guys know if it works, i have had serious pressure loss and (i assume) very serious detonation. i need to try something to fix this problem, i cant do baffled fuel cell.

 

This might work with a carbed car running a fuel pressure regulator BEFORE the carbs, but after the fuel pump. In this case you would have higher pressure at the pump than at the carb.

If you are running EFI and have the FPR AFTER the fuel rail (presumabally the case with all EFI systems), then you will have at most the same pressure in the sump as you have in the fuel rail (unless you can rig two FPR's in the system, one before and one after the fuel rail).

If your FPR is set to 45 psi, then at best you will have 45 psi in the Accusump. As it empties you will have even less pressure. The result will be an increasing lean mixture.

You will also have to worry about leaning out as the sump refills.

Still a neat idea though, it's just that the engineering might be harder than doing the old fashioned surge tank.

Scott

 

hi.

i use an accump in my vintage racecar for oil control. works well.

just a thought; do you want 2 quarts of pressurized gasoline in an aluminum container in your engine bay during a race?

i don't think i would!

good luck, and be safe.