canadaisintexas

Hey guys,

This is my first post in this section and forgive me if this has been covered already but i did search for 30min.

I want to go with a fuel cell to feed my fd project car. It needs to have decent capacity as this is my summer Daily Driver and i use it for longish trips. With that said do you guys have any suggestions? Dosent need to be the best out there just a decent compromise between functionality and price

The rest of my fuel setup will be as follows

-6 Braided Earls Fuel Line
Walboro Fuel Pump Directly wired to battery
Aeromotive A-1000 FPR
Feeding a LS1 With aftermarket Fuel Rails and Ford 36lb injectors

Thanks,

Rob

christaylor

Look in the various catalogs. Racer Parts Wholesale, Pegasus, and Jegs are the first ones I'd look at. Since you're not worried about sanctioning body rules, I'd go with a plastic cell from makers like Jazz, etc. Much cheaper than an aluminum can/bladder fuel cell from Fuel Safe or somebody like that.

canadaisintexas

Would something like this work well? I dont know quite how fuel cells work exactly so will i still have some degree of protection with a fuel cell?

http://store.summitracing.com/defaul...5&autoview=sku

christaylor

A fuel cell is only as good as its mounting location.

Quite honestly, on a first gen, I think the stock tank is better than a fuel cell. Mostly because it's so easy to mount them in an unsafe location/manner, but also because the stock tank passed tests to be in the location it's in.

Not knowing where the tank is located on a 3rd gen, I can't really comment.

carbon man

there is an issue with fuel serge depending on what you use your car for. If you do any circuit racing or lap dashes you will want to have an extra fuel catch pot that will allways be full to make sure you don't suck air. This pot is usually mounted on a FD above the diff and is plumbed into the fuel delivery line after and has the fuel return added to it with an overflow back to the main tank. If you only do legal road speeds you should have no problem. I don't know what the road rules are for where you are and what you can change. In Australia I built 120 litre carbon fibre fuel tanks for Mazda Australia that they got ADR approval and fitted to the RX7-SP's. I did 2 versions of these, one was the road version that had baffles very similar to the original RX7 tanks and then I did a race version that had 12 one way ball valves in the baffles which prevented fuel serge (but were very noisy just driving around)

~ian.

canadaisintexas

all i have to say is wow, this is where all the real knowledge is on rx7club

Also i was thinking about mounting it in the trunk. Under the Rear strut bar (i think thats what that black bar is?) Would this be a bad place to put it in terms of safety?

The stock FD tank is mounted just forward of the Rear bumper and to the left of the exhaust btw

Rob

NasaPro7

Why go to a cell?

For a street car, stick with a factory tank. many $$$$$$$$$ worth of enginering went into its placement, mounting and specs.


Marcus

Ikestaa

If it were me, I'd isolate myself from the tank (i.e. keep it outside the driver's compartment). As stated, the only real issue to worry about is serge, which you can cure using a much cheaper method.

carbon man

one of the benifits of having the fuel tank below the rear floor is getting the weight down low.
This helps lowering the centre of gravity. The Carbon tank we used in the RX7-SP was basicly 50mm deeper than a standard tank so when it was only part full compaired to a standard tank the fuel weight sat lower. The lower and the closer to the middle of the vehicle you can get the centre og grafity the better the car will handle. The tank also looked good as you could see the polished Carbon Fibre protruding below the rear bumper.

~Ian.

Ikestaa

Wait, are you going to track the car at all? I saw that this is going to be your summer daily and maybe for some long trips. If that's the case, stick with the stock tank and don't even worry about a serge tank.

canadaisintexas

This car will be tracked a couple of times a month. The main reason for going with a fuel cell is i am going to be running an exhaust exiting out of both Back right and back left corner and having a rear diffuser made for me to allow this. I am going with an LS1 but didnt want the poor ground clearance i will have if i go with duals running out the same side.



So basically what you guys are saying is that its not worth it to go with a fuel cell and that i should stick with the stock tank and just do new fittings on it to allow for my -6 fuel line?

Ikestaa

I see. Sounds like there's a number of factors to consider. If it were me, I'd run a larger single as apposed to duals. Run it either out the side (that's how I did it on my LS1/FD) or out the right rear. Run whatever diffuser you want and use the stock tank with a serge tank. I haven't had mine running long, but I have run it at Road America. Stock tank will do fine, just keep it filled up. Running an approved fuel cell is going to get costly in between the tank, mounting, fittings and hoses.

AMRX7

Have you considered cutting out the spare tire well and having it replaced with flat plate? Not sure that will give you enough room with your diffuser or not.

I have a small Summit aluminum cell (5gal) mounted in the tire well, with another cover over it to separate it from the passenger compartment. Anything larger than mine is probably going to be a real pain to fit inside the car, and that's before you put in a bulkhead for safety.

-Andy

canadaisintexas

I think im just going to go with the stock fuel tank, keep it full and run a serge tank. Thanks for all the help guys.

Thanks

Rob

TrentO

Typically, the only reason to go to a fuel cell is the requirements of a sanctioning body. I'm in the pocess of converting over my Turbo FC to an FT-3 rated cell. I have two reasons for converting, one is sanctioning body, the other is fuel supply issues. I'm re-plumbing my entire fuel system to fit the GT35R turbo I'm hanging off then engine. My current thoughts are down to three distinct strategies.

1) Use a low pressure pump in the cell feeding an external surge tank. An Aeromotive A1000 pump drawing from the bottom of the surge tank, AN-10 lines up to the custom primary rail, an AN-10 line to the secondary rail and finishing up with an AN-10 A1000 pressure reg, which uses the normal fuel line for the return to the surge. The surge has a top return line to the cell which keeps the fuel circulating. This is the overkill solution

2) Same setup, but two pumps feeding from the surge tank. Each pump feeds one custom rail and has it's own regulator. They T into a return line and go back to the surge tank.

3) ATL Black box internal surge tank in the cell using a single high pressure high volume pump. AN-6 line to the custom rails and an AN-6 pressure regulator.

My concerns center around the fuel delivery potential of the stock 5/16 fuel line and the slightly larger 3/8 (AN-6) line. I've done the math and the increase from 5/16 to 3/8, while only a 1/16 increase does yeild about 150% the area. My thoughts are, can a 3/8 line feed 450 hp at the crank?

I'd like to hear some thoughts,

-Trent

carbon man

I would suggest putting more than one low pressure lift pump, if you have a lift pump in each corner of the cell then you will always have at least 1 lift pump with fuel at it at any time. If the other lift pumps get air for a short time will not have any efect on the fuel flow.

The serge tank, if it has 2 pressure pumps but you use 1 as the main and have the out let to that pump part way up the serge tank and the 2nd pump as a reserve pump at the bottom that you only switch on if you run out of fuel or the main pump fails.

The size of the fuel lines are not as much of a problem to the flow as the fittings and the placement of the fittings. ie. try to have straight fuel line feeding the pump for as far as you can, DON"T put an elbow straight to the inlet of the fuel pump.
Also try not to have the fuel line rise up then back down as it will air lock in the high point and require extra pressure to push the fuel past the air bubble, Try to make the injectors the higest part of the fuel system as this will self bleed the air, keep the regulator close to the fuel rail as that is where you need the fuel pressure accurate.

~Ian.

Carl Byck

Check my page at teamfc3s, good pics, supports 600+fwhp in my road race car with an A1000

TrentO

Thanks Carl and Ian, I think I'm going to do option 1.1. Here's what it will look like:

ATL Sport Fuel cell (FT3 certified)
2 duckbill AN-8 pickups (included in cell)
2 fuel filters (1 for each transfer pump)
2 Holley Red Pumps pulling from the cell, one from each duckbill pickup in each corner
1 Surge Tank w/ 2 AN-8 supply fittings, 1 AN-10 bottom pump feed and an AN-10 return way up on the surge tank. (I will be welding up the surge tank, so I can put fittings wherever)
Aeromotive A1000 pump AN-10 from the cell, AN-10 into braided line, into 5/8 aluminum hard line
AN-10 braided line to custom primary rail (1/2 inch holley extrusion)
AN-10 line from custom primary rail to custom secondary rail.
AN-10 braided line to Aeromotive Pressure reg and AN-6 return line going back to the surge tank.

I'm seriously considering making my return lines out of the finned aluminum extrusion to try and cool the fuel on it's way back to the cell.
The only other outstanding issue is going to be refilling the cell. Since we do some 2 hour events I'm wanting to plumb in an external fueling door (likely see if I can use the stock location). I then will likely have to bulkhead the whole thing off as I don't think they make braided filler line.

-Trent

DamonB

If your surge tank is anything but miniscule I can't see how this would be a real problem. The engine is drawing fuel from the high pressure pump in the surge tank. As long as that pump is never starved I don't see a problem.

If I had a surge tank I would absolutely plumb the return line back into the surge tank.

RX7iXi187

howdy ya'll

TrentO

After reviewing the Aeromotive website I've made a few revisions to my plan, all at the fuel rail end. They advise using a Y block from AN-10 to two AN-8 lines, each to a rail and then AN-8 from both rails back into the AN-8 side ports on the pressure regulator. Seems like a better solution for even fuel distribution. I'm currently running 550 primaries and 1680 secondaries, so "even" distribution might not be desired though. I think this will make a better setup though.

-Trent