83RDRACR

I have had several request about how I mounted the RCI-2161A 15 gallon aluminum cell behind the rear axle in my " HOME BREW ROAD RACER" thread. While most of the info is in the original build thread I thought I would make specific thread to explain the install and fabrication required.

The good....

1. 15 gallon aluminum fuel cell mounted UNDER the car, leaving all floor boards and crumple zones intact.

2. able to fill the tank from OE fuel door....don't have to open hatch to fill up.

3. has -8AN fittings for outlet, return and vent. Vent has built in rollover valve.

4. fuel tank sits low and behind rear axle for better weight distributtion.

5. tank can be adapted to internal fuel pump.

6. comes with 90 ohm GM style fuel gauge.


The bad.

1.The tank leaves little or no room for exhaust behind the rear axle on either side.

2. some welding and fabrication are required.

3. fuel slosh is inherent with these tanks so use of foam bricks is highly recommended or could fabricate an internal sump.


Here we go. The tank is RCI-2161A, and it measures 30" long x 12" high x 9" deep and holds 15gal of fuel. They do make a 19gal cell but it is 12" deep and I couldn't come up with the extra room without cutting into the storage well in the trunk. https://static.summitracing.com/glob....jpg?rep=False


My car has been highly modified around the rear axle area but tank will fit with minimal mods to cargo area floorpan. The only real prep to the floor pan is to cut out the rear fuel tank strap mounts. Cut them off about even with the stiffening ribs in floor. Drill out the spotwelds then carefully make the top cut so as not to cut into trunk sheet metal.


Next I used "camper tape" that I got at NAPA to protect all the corners of the tank.


With the tape on I started to make 1 1/4 angle iron frame. Cut out the top pieces to length set in place, hold against foam tape with a slight pressure and tack in place. To aide in fitting the frame to the underside of the car I drilled 3, 3/8 holes in the rear top piece so I could bolt top frame to cargo well wall. Center the top in between the frame rails, make sure it is level side to side, and mark and drill the 3 holes into the cargo well. These should be in the area where the seams overlap. With the top done, measure and cut for legs to hang down from the top and tack those in place. You should have something like this when done.


For the bottom of the frame I used 1 1/4 x 1/2" rectangular tubing. cut the legs and fit the tubing so it is just flush with the bottom of the fuel cell. Let the rear tube extend past the cell 6 inches or so, so you have enough material to attach the rear, bottom mounts. Again keep a light snug fit of the tubing to thr foam tape.


.

I added 2x3" mounting ears to the top front of the frame.


I used a piece of plywood as a temporary bottom plate to check fit and to also jack and hold frame in place. Withe the frame bolted in by the three top, rear bolts. jack and shim the whole frame so it is level, side to side, and front to rear. Once level mark the frame rails where mounting tabs will have to be welded in to match the front upper mounting ears. You will probably have to spend some time with cardboard and a grinder to contour the frame tabs to match the frame.. There is not a lot of space on the sides of the tank frame so they have got to fit close.





So I dont run out of space I will start another post.

83RDRACR

With the tank level visually pick the area on the frame rails where the extended, lower, rear, fuel cell, frame tube is under. Use a ruler against the tube and mark the frame. Now measure out about 3" each side of mark on the car frame rails so you have about a 6 x 2" rectangle marked out on each frame rail. Using either 1/8" or 3/16 plate, cut out two 6 x 2" pieces and and secure to the frame rails with a couple screws in opposite corners. Measure in about 1" in from the ends and center punch for two holes for each plate. Drill through the plate and frame rail with a 3/16 bit for pilot holes. Mark the plates so you you can tell front from rear and right side from left. Remove the plates.



Drill the holes in the plates out to 5/8" and the frame holes to 7/8". A hole saw works good for both. On the backside of each plate tack 1/2-20 nuts centered over the holes. Position the plates back on the frame rails with the nuts up inside the frame rail and reattach with the screws. Bolt the plates back onto the frame brackets with 1/2-20 x 1" bolts. Double check with a straightedge that the lower fuel cell frame tube still aligns with the middle of your bolted in plates and doesn't interfere with the mounting bolts.

The hard part now is to joint the fuel cell frame to the bolted in plate on the frame rail. After several failed attempts with angle finders I finally cut a 1 1/4 wide strip of cardboard and folded it so it matched the contour/angles of both surfaces. I cut some of the 1 1/4 x 1/2 tubing and made the short struts to span the gap from from fuel cell frame to car frame.


finished fuel cell mount looked like this.


Bolted in is like this....


for the bottom plate I used 1/4 aluminum diamond plate. I welded in ten, 3/8-16 threaded bungs into the bottom of the frame.




I used countersunk SS allen head screws to hold the diamond plate in.


Photo bucket has shutdown so will have to finish later.

David

83RDRACR

comparison of stock tank vs RCI fuel cell. Both hold 15gal.




You can remove fuel cell without disturbing any rear suspension parts.


tank hangs about 2" below cargo well.




filler neck and hose. Fuel cell filler neck is only 1 1/2"dia. I replaced factory gas cap and neck with a JAZ cap and neck assembly and used a 2" to 1 1/2" exhaust adapter. the fill pipe is 1 1/2 stainless header tubing. Connector hose is NAPA 1 1/2 fuel hose.

83RDRACR

To plumb the tank and make it easier to install and remove. I welded a 2x3" plate on front right and welded -6 AN hose connectors. I reduced the inlet and outlet fitting on tank to -6 and plumbed it all with push lock hose and fittings.






The vent tube ended up being 1/2" clear vinyl hose from Lowes with a small breather filter clamped to the end. Hose was zipped tied to filler tube and top end is just below filler neck in wheel well.

I hope this thread helps people to see they don't have to put a 15gal fire bomb in their trunk that is open to the passenger compartment. I cringe everytime I see a fuel cell install post here.

David

makaveli09

Very nice ! I may have to copy some of your install.

83RDRACR

MAKAVELI09, Thanks. it really is a clean install. One of the best benefits us that you can remove the fuel cell without disturbing any suspension parts. The other big plus is that it is under the car and not in the car. All of the factory crumple zones are still intact. This installation should be as safe as factory tank was.

It scares me to death to see so many post on TGO where someone wants to make a street/strip car and they mount the cell in the cargo area and "seal" it of with an aluminum firewall that seals against the deck. this sOK for a DEDICATED drag car that does not see any street use. They go to great lengths to seal off the tank from the OUTSIDE when they should be sealing it off from the INSIDE.

There are so many things wrong with an in the trunk fuel cell install.

1. Cells are mounted to extreme rear of cargo area eliminating any crumple zone.

2. If vehicle is hit in the rear chances are that the hatch will spring open eliminating the seal from the "firewall" and exposing the cell and its fuel to the passenger compartment.

3. Another hazard comes when you have to fill the cell. You have to open the hatch to fill it,again exposing the cell and its contents to the passenger compartment.

4. With the cell mounted in the cargo area it sits under that large rear window, a virtual greenhouse. Temperatures can easily reach 120* ore more on any given sunny day. The fuel is practically turning into a vapor right in the cell. Vapor lock and flooding problems would seem to be the order of the day.

Other than on a dedicated drag car where the tanks are rarely more than 5 gallons and the risk of a rear end collision is minimal, do I feel it is safe to mount a fuel cell in the cargo area.

That's my line and I am sticking to it.

David

customblackbird

iTrader: (15)

You know the stock fuel sender is not a 0-90ohm right?

Also how does it adapt to an internal fuel pump? wondering how your going to adapt a exernal fuel pump when the inlet/outlet are at the top of the tank....

OTher than that its a clean install. You could prob run a cheap OBX ebay SS catback with no muffler but it would be loud.

makaveli09

Yeah I hear ya. I don't like the fuel cell in the hatch.

articwhiteZ

iTrader: (56)

or ya could add one that fits with the stock mounts/straps...(lower back of aluminum tank 12an fittings)


top of tank..showing 2 10an return/vent..and sending unit location..
filler neck using the cap and top of neck off of later Camaros..it also drops 15+lbs off the car..

83RDRACR

artic, this is the nicest 3rd Gen tank I've seen. Wouldn't work with my 3 link but great for a more stock vehicle. What company makes this and what is cost.

articwhiteZ

iTrader: (56)

http://www.behindbarsracecars.com/Default.asp

I run a ladder bar set up..so its a bolt in..they are nice looking..(they have redone the tank to work with the filler necks off the cars)