Any tips for mounting a fuel cell?

[Roostmonkey]

I'm building the frame to hold a cell in my Z. Its a small 12 gallon cell that measures 16.5 X 16.5 X 9" tall. My plan is to mount the cell centered right to left to allow room for dual exhaust.Also centered within the subframe front to back. I was going to make the frame 8" deep so it would stick up 1" above the deck.This would allow a bolt down cover/ frame to act as the hold-down staps.Are there any problems with this setup? Thanks

[Boy from Oz]

I wonder why you don’t mount the cell below the floor rather than protruding 1” above. Are you planning on making a complete cover for it? It is a requirement down here that the cell/tank be completely isolated from the cabin area for fume and fire risk reasons. It’s one regulation that makes plenty of sense to me.

 

Maintaining the original floor profile might make more room to carry a spare tire.

 

The big downside I see from cells is the usual need to fill them from inside the car. With your known fabrication skills I wonder why you don't fabricate your own tank with a rear external filler capability - that's the path I'm taking.

[trwebb26]

Only problem with what you've said is that it would stick up an inch... When the car is level - the front of the cell will stick up more than the back because the rear subframe is angled. Make sure that thing is level or the sump will do you no good.

 

Left/right - I centered mine - for dual exhaust that will be your best bet.

 

Fore-aft - Make 100% sure that your 90 degree fuel cell fittings coming off of the sump have clearance to the rear valance - including when you go to thread them onto the outlets of the cell. Also make sure that it isn't too close to the lower rear control arm mount. Obviously the more forward you can get it the better (CG)

 

Up/down - IMO the most important measurement. Design considerations include:

- You want to make sure you have adequate ground clearance

- For me - the exhaust actually went under the cell some... make sure it is high enough to clear your exhaust including any heat shield you may want to put in place.

- Obvioiusly you have to have the first two things and try to keep it as low as possible to minimize the height of the CG and keep it out of the trunk area as much as possible. Almost all racing rules require that the fuel cell and all of the fuel lines be outside the driver compartment - the more it sticks up the more you'll have to work to cover it up in the trunk.

[Roostmonkey]

thanks guy's. My concern was ground clearance. The car is totally stripped and on a rotissieri at the moment so I cant get a look at how low 9+ inches will be.I'll have to look at another car and take some measurements.

[240hoke]

Do not mount it abouve the floor. I think you will regret the decision for a long time (I have). I want my floor space back and if you stick it through the floor you will definitely have to make a sheet metal cover for it so you have a 'bulkhead' between you and the tank.

 

I am going to redo my cell when money permits and run a fuel safe unit completely under the floor and hook it back to the factory filler location. I also will run a in tank pump.

 

Whatever you do make sure you get a cell with an excellent baffle and sump setup. I have been running a Jeg's cell and it is the biggest piece of junk in the world.... I wish I would have never removed the factory tank.

[rturbo 930]

Do not mount it abouve the floor. I think you will regret the decision for a long time (I have). I want my floor space back and if you stick it through the floor you will definitely have to make a sheet metal cover for it so you have a 'bulkhead' between you and the tank.

 

I am going to redo my cell when money permits and run a fuel safe unit completely under the floor and hook it back to the factory filler location. I also will run a in tank pump.

 

Whatever you do make sure you get a cell with an excellent baffle and sump setup. I have been running a Jeg's cell and it is the biggest piece of junk in the world.... I wish I would have never removed the factory tank.

Mind going into detail as to why you wish you kept it, even against a better fuel cell as mentioned in your post? I can't decide if I want to keep the stock tank in my 240z. The spare tire well is rusty, not sure if I want to replace it.

[240hoke]

I would have kept the factory mainly for cost reasons and that the factory filler and evap breather system could be utilized. Having the additional storage in the spare tire well would be nice as well. The plastic cells (and aluminum IMO) are total garage and are not any safer then the factory tank and have terrible slosh issues even with foam. I am of the opinion that if you want a cell then get a REAL fuel cell with a blatter.

 

I think the fuel cell access flange welded to the top of a factory tank with the ATL black box and internal pump is really slick. Keeps the stock appearance and gives a really sweet fuel setup.

 

Im sure its going to cost me over 1000 to get an entire fuel cell setup with internal baffles, in-tank pump and sending unit.

[Kevin.pk]

Do not mount it abouve the floor. I think you will regret the decision for a long time (I have). I want my floor space back and if you stick it through the floor you will definitely have to make a sheet metal cover for it so you have a 'bulkhead' between you and the tank.

 

I am going to redo my cell when money permits and run a fuel safe unit completely under the floor and hook it back to the factory filler location. I also will run a in tank pump.

 

Whatever you do make sure you get a cell with an excellent baffle and sump setup. I have been running a Jeg's cell and it is the biggest piece of junk in the world.... I wish I would have never removed the factory tank.

 

 

AGREED 100%

 

 

Although I did mount mine below the floor and put a dzus fastened sheetmetal top/cover for it.

 

I do have a 16 gallon plastic cheapo drag cell and regret it. I only removed the factory tank to shave the fuel door and put the filler behind the license plate. Instead, I have to remove 7 dzus fasteners to fill up my gas tank until I figure out exactly what I want to do and upgrade to a proper ATL cell.

 

I wish I would have just modified the factory tank.

 

 

 

As far as ground clearance goes, my cell is 11 inches tall and sits 1 inch below the rear deck. my cars rocker is at ~7 inches, and I have 7 3/4" from the bottom of the rear sump to the ground.

 

Pictures to better illustrate....

 

 

 

I'm not sure if the rear deck is the same height across all s30's or not but either way, hopefully this helps some.

 

and this is the current cover for the top... (I'm not exactly happy with it but it keeps the fumes and rain out.)

 

[TheMission]

AGREED 100%

 

 

Although I did mount mine below the floor and put a dzus fastened sheetmetal top/cover for it.

 

I do have a 16 gallon plastic cheapo drag cell and regret it. I only removed the factory tank to shave the fuel door and put the filler behind the license plate. Instead, I have to remove 7 dzus fasteners to fill up my gas tank until I figure out exactly what I want to do and upgrade to a proper ATL cell.

 

I wish I would have just modified the factory tank.

 

Someday I may think of forking out thousands for an ATL or such, but still think it can be done better than above, so I gave it a shot -

 

I still went with the cheapo setup and if I have too many issues I'll let you know... I still am under the floor, but I am up higher than the pics above due to how I set it up and most likely the tank I chose. Sloshing with foam and starvation issues may hit me, but I can always make a secondary can and run a low pressure pump to that and high pressure away to fix that little issue.

 

I may have issues with the return and vent lines where they are at, but I can always make lil' boxes to section them out of the cabin if I get flack for it. Here's pictures of my install.

 

First, the hole

 

Here's the mount I welded up and painted... (I used 1/2 inch weatherseal padding on the sides of the mount that support the fuel "Cell" to protect the tank from flex and possibly cracking issues)

 

Here's the tank in a test fit shot to show how and where it sits

 

This shows how "Low" the tank sits... It's actually impossible for it to hit the ground, as the mount would hit first anyways, but still is a tad higher than the lowest point of the rear transaxle assembly (it looks off kilter in this pic, but I just took these for reference shots and it sits perfectly level currently)

 

Here's the panel with the vent line hooked up. I may end up just making little boxes to cap off the lines and keep them seperate from the cabin, which would be easy enough

 

The "Fuel Door" is a dragster access panel from jerry bickel racing and seals off the tank from the cabin and allows quick access for fill ups... The side panel in the bottom right is a removable panel to access where the odyssey battery is, as I have a little mount for the battery under the panel now as well.

[bobbyc]

i did exacty what you want and what everyone says not to do...and ground clearance was the reason. here's mine from the rear.

 

 

i had 90 degree angle aluminum welded about an inch from the top, built a frame in the floor, and set the cell on that frame so it's sealed from everything outside...i can't find a pic in the car...can post one in a bit.

Edited May 7, 2010 by Bobby C.

[ModernS30]

i did exacty what you want and what everyone says not to do...and ground clearance was the reason. here's mine from the rear.

 

 

i had 90 degree angle aluminum about an inch from the top, built a frame in the floor, and set the cell on that fram so it's sealed from everything outside...i can't find a pic in the car...can post one in a bit.

 

I'm pretty sure the reasoning behind not putting it inside the car is so you can actually race that car. Plus its safer that way.

[bobbyc]

yeah....i understand the reasoning...i'll just have to build a cover...not a huge deal for me...btw...i installed that cell and had everything built ~5 years ago.

Edited May 7, 2010 by Bobby C.