Fuel system - BRFPR? -OEM or upgraded fuel pump?
 

As most of you have probably already observed I am currently in the process of converting to standalone ECS. The topic of fuel system adequacy has came up a few times. My car is 2.2 displacement with TVS on 2.8" equivalent (2.9" w/ ATI OD) with 2X 3gph 50:50 w/m injection, 650CC fuel injectors, ZZP S2 blower cams, LSJ head with exhaust side ports gasket matched, 3" exhaust with boost maxing out at about 19-20psi. I had previously got away with stock fuel system with my stock ECM with Trifecta tune but I'm not sure if the injectors were spraying properly or if the tune was even working well in the higher rpms. The question I have now is should I go ahead and bite the bullet and install a boost reference fuel pressure regulator? If so, will the stock pump be sufficient or should I upgrade that while I have the tank down? If I should upgrade the pump does anyone know if the AEM 320 lph E85 pump works? I like the idea of having Ethanol ready components in the event I decide to go that route in the future.

I also have a question about how the stock fuel system and the BRFPR works. From what little I know it appears the fuel pressure is essentially regulated by a simple pressure relief valve mechanism. When the fuel pressure exceeds the spring force it lifts the ball from its seat which allows the excess flow to bypass back to the tank. However when I read ZZP's website page for their BRFPR they have this line that is bringing that idea into question. "When the canister is removed, open the canister and clip off zip ties holding the clips on the regulator. Now open the regulator to expose ball and spring tab, next remove ball and spring tab, then clip fuel diverter back on and re-install canister." If the ball and spring is a pressure relief valve and you remove the ball and spring I'd think it would allow the flow to continually bypass freely back to tank and the system would not be able to build pressure. Does the BRFPR then somehow connect to the exit port of the old pressure relief so the fluid cannot return back to tank freely but must now pass through the BRFPR first?

Yes I would recommend using BRFPs and the aem 320lph is commonly used on these cars for that system. Essentially you delete the stock regulator and add in an adjustable one. ZZP has two systems, one that is a boost referenced dead head system, and one that is a full return style. In my opinion, full return style systems give much better control over fuel pressure.

I am putting together a BRFPR return system, got this bad boy 044 style pump: https://www.deatschwerks.com/blog/dw...k-outside-tank

to run in a trunk mounted surge tank like this: https://www.ebay.com/itm/Universal-2...kAAOSwAZVbK0L~

When using a fuel pump with a greater power draw do y'all us a relay in the truck with power coming straight from the battery or how many amps are the stock wires good for?

What's the idea with these? Is it so you don't have to worry about the restriction of the stock in tank system and the stock fuel lines?

Yes, the factory pump constantly fills a 1-gallon surge tank, like a buffer tank, then the high flow pump pulls from the surge tank. The largest flow demand is at WOT, so unlikely the pump will empty the surge tank under a WOT pull especially with the factory pump making up the fuel.

The other major advantage is to prevent fuel starvation during extreme g-forces on the track.

Yeah I get that it's just basically a primary reservoir that the stock pump keeps full from the stock tank which becomes a secondary reservoir. I was mainly wondering what advantages it has over beefing up the flow from the stock tank. Fuel starvation makes sense. I just didn't know if there were other specific limitations of the stock fuel supply (other than the pump) that made a remote primary tank a superior alternative.

Btw, I ordered ZZP's BRFPR and their AEM E85 pump.

Full return system? Ive never used/installed theirs because their website description is kinda confusing on it. I have the OTTP system on my car.

This setup is probably overkill for most people in our Ecotec world. I'm dreaming of 600 bhp.

For abnormally high fuel flow needs, with a surge tank you can leave the stock fuel system alone with a stock fuel pump. You adapt to the stock sender unit with GM quick disconnect adapters to convert to AN fittings (for the fuel returning, can use the EVAP outlet or add a bulkhead AN fitting to the sender unit). Bulkhead probably better to put a down tube in for the return fuel.

The main benefit of a surge tank in general for the whole aftermarket is to overcome fuel starvation.

If I had the budget, I would get something like this: FST, Fuel Surge Tank, Standard

A fuel surge tank (FST) is designed to prevent fuel starvation to the engine on vehicles with inadequate fuel tank baffling. The FST fuel pump(s) directly feed the fuel rail(s). The volume of fuel inside the surge tank acts as a buffer to always keep the FST pump supplied with fuel. This volume is maintained by the main fuel tank's pump as well as the fuel returning from the fuel pressure regulator. Excess fuel in the surge tank is returned back to the vehicle's main fuel tank.

The surge tank also provides a quick and easy way to upgade any standard fuel system without the need to modify the stock fuel tank or pump. This is an excellent fueling solution for vehicles installing large fuel demand power upgrades such as forced induction.

Not full return. I'd think I would need a different"flow-through" fuel-rail with the regulator on the opposing side of the supply to see an advantage from that. I will be connecting the regulator back by the fuel tank. If it doesn't work like I anticipate it will I will do something different. Just thinking about it I don't see it being an inferior setup except it may yield slightly less pressure at the injectors because it will be regulating pressure upstream which should see a slightly higher pressure than at the injectors from drop through the fuel line. I could very well be missing something those are just my thoughts on it.

You just use an lsj fuel rail and I think they use the EVAP line as the fuel return line. The problem with a deadhead system is even though youre referencing manifold pressure, you can still be dropping pressure at the rail itself. It works much better with the regulator at the end of the loop, not the beginning. Basically on my setup, im directly controlling the fuel rail pressure because the reg is so close to the injectors. Ask trevor about the fuel pressure drop he was seeing on the fox car with the deahead system. The nice thing about using the aem tho is that it can compensate for fuel pressure drops if you have a fuel pressure input.

If you want a better explanation you can talk to armcclure. Im not good with words and stuff.

I get what you are saying and it makes sense. I just have my fuel pressure sensor and everything accounted for and that will make me have to get a fuel rail and other parts. I'm going to try it, if it sucks I will change as I can still us the same parts pretty much. May need some different fittings.