Fuel Tank General Knowledge

[freds]

I'm at the point of fitting the fuel tank and need some information (before I jump dumb).

I have my engine and transmission + all the rear suspension and axles fitted + ride height set.
Now (a bit late I know!) I'd like to install a firewall between the tank and engine, but am not going to remove the engine to do it, so I'm looking for a way to do it on the cockpit side of the chassis.
Info that will help me check if the Boyd tank can be moved:

1. Does the Boyd tank sit on the FFR installed steel plate?
2. What are the overall dimensions of the Boyd tank?
3. I have read that with the Boyd tank installed an extra 3" of legroom is possible, presumably by moving the rear cockpit firewall back. Is this correct?
4. If yes...could the Boyd tank be moved forward and bolted to the vertical chassis member with stand-off brackets? Allowing space for a firewall and air-space gap?

All info and opinions welcome

Thanks in anticipation

fred

Photo lifted from Jerome's thread (thanks Jerome)

JeromeS13 Boyd Tank.jpg

[wallace18]

I'm at the point of fitting the fuel tank and need some information (before I jump dumb).

I have my engine and transmission + all the rear suspension and axles fitted + ride height set.
Now (a bit late I know!) I'd like to install a firewall between the tank and engine, but am not going to remove the engine to do it, so I'm looking for a way to do it on the cockpit side of the chassis.
Info that will help me check if the Boyd tank can be moved:

1. Does the Boyd tank sit on the FFR installed steel plate?
2. What are the overall dimensions of the Boyd tank?
3. I have read that with the Boyd tank installed an extra 3" of legroom is possible, presumably by moving the rear cockpit firewall back. Is this correct?
4. If yes...could the Boyd tank be moved forward and bolted to the vertical chassis member with stand-off brackets? Allowing space for a firewall and air-space gap?

All info and opinions welcome

Thanks in anticipation

fred

Photo lifted from Jerome's thread (thanks Jerome)

JeromeS13 Boyd Tank.jpg

Look at my build thread. I used the boyd tank and made my own firewall and insulation. I can install and remove my firewall with the engine in. You won't be able to install as many screws as I did because I did it before engine install. You can see the tank installed on a few threads as well to get an idea of dimensions.

[freds]

Look at my build thread. I used the boyd tank and made my own firewall and insulation. I can install and remove my firewall with the engine in. You won't be able to install as many screws as I did because I did it before engine install. You can see the tank installed on a few threads as well to get an idea of dimensions.

Thanks. I had "studied" your thread. I just want to be sure there are no unforeseen problems for what i want to do.

I intend doing the opposite of what you did.......move the tank further forward (I'm not after leg room)....and leave a gap between the tank and the vertical part of the chassis. That way I can easily install the firewall on the tank side (instead of engine side, as you have) and still have a decent air gap between the firewall and the tank.

I'm pretty sure that will work, but someone may see a pitfall I didn't think of.

Thanks

fred

[AZPete]

Fred, I installed a rear firewall after I had the engine in (not the smartest way). My firewall is in 4 parts: #1 is a rectangle between the headers and the Boyd tank. This is not removable because if I ever have to get to the tank I can get there from the seat side. I removed the header for room to drill and rivet the lower edge and then for the upper edge I drilled through from the tank side and used small hex-head screws since there was no room for riveting. The upper panel, parts #2, #3 & #4, are all triangles to match the frame work and each is bent 90 degrees at the bottom for rivnuts into the frame I can access from the front (tank) side. The top and sides of these panels are held rivnuts (1/4" holes drilled from front with 3/16"holes in the panels for #10 allen-head bolts). I can remove each of the upper triangular panels easily from the tank side as needed to do wiring, access engine belts, etc.

Since you are placing the Boyd tank in a forward position I don't think you will have to bend the firewall panels in front of the Boyd tank. I need the foot room so I took my upper panel to a metal shop and they bent it an additional 20 degrees ($20) to fit the Boyd tank in the back position. I can post photos if this does not make sense.
Pete

[freds]

Thanks Pete. That all makes sense. Since I'm not going for the leg room, I think my installation will be a lot less work than your "heroic" effort.

Appreciate your and Wallace's response

fred

[waruaki]

Thanks Pete. That all makes sense. Since I'm not going for the leg room, I think my installation will be a lot less work than your "heroic" effort.

Appreciate your and Wallace's response

fred

Fred. I see your not after leg room but I would suggest before you bolt anything down or drill any holes for your fuel tank arrangement that you fit the drivers seat and the peddle box to be sure your comfortable. I just fitted the drivers seat earlier in the week in ours and my Dad who stands 5.7" wishes we had more leg room. Granted we are running the Factory Five tank and WRX seats. If we had the Boyd tank we would have it mounted it as far to the rear as possible.

[wleehendrick]

Fred. I see your not after leg room but I would suggest before you bolt anything down or drill any holes for your fuel tank arrangement that you fit the drivers seat and the peddle box to be sure your comfortable.

Agreed... I'm 5'11'' my Boyd tank is on the way. I've mounted my pedal box, adjusted my seat's side-mounts where I want it, just set it on the frame, and found I need to move the firewall back about an inch. Since I'm relocating it, I may as well make as much more room in the cockpit as I can.

[waruaki]

Agreed... I'm 5'11'' my Boyd tank is on the way. I've mounted my pedal box, adjusted my seat's side-mounts where I want it, just set it on the frame, and found I need to move the firewall back about an inch. Since I'm relocating it, I may as well make as much more room in the cockpit as I can.

If we can't get the leg room we're looking for, a Boyd tank may be in the future. I like the stock WRX seats but if someone could tell me they picked up 3" of leg room from racing seat brand X I might go that route as well.

[Xusia]

Has anyone considered modifying the FFR supplied tank? I'm not a metal worker, so I have no idea what's involved. Feasible or not?

[flynntuna]

I thought FFR is developing their own "slim" tank.

[waruaki]

It could be cut and rewelded but you would lose some capacity.

[Xusia]

Hehe. My motorcycle gets maybe 115 miles per tank before hitting reserve, so I'm used to dealing with a very short range. If I could get more leg room and fit a proper sub [behind the driver's seat], it would be an acceptable trade off.

[metalmaker12]

Has anyone considered modifying the FFR supplied tank? I'm not a metal worker, so I have no idea what's involved. Feasible or not?

I would use the FFR tank for a shooting target, or maybe fill with cement and use it for an anchor. I would deff not try to re- weld it.