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-   -   FB Fuel Pump question (https://www.rx7club.com/rotary-car-performance-77/fb-fuel-pump-question-647367/)

docholiday 04-28-07 03:00 PM

FB Fuel Pump question
 
alright. i've searched a bit to no avail. i've got a base model 83 but am puttin in a new NA motor and injecting it. what do you guys recommend is the easiest and most efficient pump to put in to supply the injected setup with enough fuel? thanks.

rmriggin 04-28-07 06:01 PM

A rotary vane style pump like http://store.summitracing.com/partde...5&autoview=sku
and then get a regulator for it. Another option would be to get a gsl-se tank and pump or try and fit a 2ng gen tank and pump.
The best option would probably find a gsl-se tank and pump because you will want a baffled tank when you go fuel injected (your current tank is not baffled).
The easiest pumps to install are the in-line rotary vane style. They are quiet also.

jgrewe 04-28-07 06:10 PM

Find one for a Ford truck at the parts store. They'll do 80psi and over 40gph IIRC, and they are cheap. You only need about 45psi so get a regulator.
To keep the stock tank make a surge tank and put it next to the big tank somewhere. Feed it with the stock pump and let it receive your other return line before sending fuel back to the tank. Anything will work that will hold about a quart or so and thatyou can make it fuel proof, something aluminum is great, look around for small pressure bottles.

renns 04-28-07 08:58 PM

https://www.rx7club.com/1st-gen-archive-71/intake-efi-prepping-1st-gen-578184/

peejay 04-29-07 12:26 PM

When I put an injected motor into the '84, I plan on using a Volkswagen surge tank/fuel pump assembly fed by a standard type pump in the stock location.

The only problem is, where to *put* the surge tank. I am thinking the best spot might be the area where the subzero assist tank normally resides, but haven't tried fitting the unit up yet.

docholiday 04-30-07 08:53 PM

awesome. i'm likin the idea of the inline msd pump. just curious about the surge tank. may be a bit of a ridiculous question but i dont see how a pump that couldnt supply my injected setup is going to be ably to supply enough fuel for my surge tank for my new pump to feed the injectors with. wouldnt it just drain the surge tank too fast?

diabolical1 05-01-07 01:21 PM

as i see it, as long as the feeder pump output volume matches or exceeds your fuel injection pump, you should be good to go.

peejay 05-03-07 08:21 PM


Originally Posted by docholiday
awesome. i'm likin the idea of the inline msd pump. just curious about the surge tank. may be a bit of a ridiculous question but i dont see how a pump that couldnt supply my injected setup is going to be ably to supply enough fuel for my surge tank for my new pump to feed the injectors with. wouldnt it just drain the surge tank too fast?


Not really.

Fuel pumps lose volume rapidly as you increase pressure. That's why the Bosch pumps designed for 250hp engines at 120psi for mechanical injection will work soooo well for much higher powered engines at "only" 50-60psi for EFI. The feeder pump will be operating at essentially zero pressure so it will flow quite a lot more than at 5-6psi (carb) or 42psi (injected).

It takes me about ten minutes to drain a fuel tank using a fuel pump that couldn't even support 50hp at 4psi. That's about 60gph or 225lph at zero PSI, imagine what even a correctly working stock pump could do.

Further, the surge tank actually has two inlet feeds: the feeder pump, and the return from the fuel rail. If your main fuel pump is properly sized, your fuel rail return will ALWAYS have flow, and it works out that the feeder pump only actually needs to be able to flow what your engine actually needs. That's even slightly overkill, since you only see peak fuel demand momentarily, unless you have an engine with a flat horsepower curve, in which case there are some racers out there who would like to beat a path to your door :)

diabolical1 05-04-07 09:05 AM


Originally Posted by jgrewe
Find one for a Ford truck at the parts store. They'll do 80psi and over 40gph IIRC, and they are cheap. You only need about 45psi so get a regulator.
To keep the stock tank make a surge tank and put it next to the big tank somewhere. Feed it with the stock pump and let it receive your other return line before sending fuel back to the tank. Anything will work that will hold about a quart or so and thatyou can make it fuel proof, something aluminum is great, look around for small pressure bottles.

hey man, long time, eh? :)

anyway, what year and model Ford truck are we talking about?


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