S14 Fuel Tank Woes

[firejackal]

So my S14's fuel tank finally developed that stress crack in the same spot as countless other people has.
And I even been running energy suspension subframe mounts for several years.

So I tried repairing the cracked area with that JB weld fuel tank putty stuff.
But I don't trust it. And I'm worried if it would be my luck and maybe a few months or another year out that another crack will develop.

So I was entertaining the possibility of using a fuel cell.
But I don't want to loose my trunk space because I recently put in work to build a sub woofer box into the spare trunk area.

So one idea was to get a long rectangular fuel cell and put it into the stock location behind the back seat and above the subframe.
Unfortunately due to the height of a 15 gallon tank, the whole top section behind the back seat (including some behind the back seat) would need cut out.

So my questions for those of you who has messed with fuel cells, or know a lot of about the rigidity of the frame. What kind of issues would this cause me cutting that area out and having the fuel cell in the middle?
I don't track the car, but if I did would that represent an issue?

I know I still have to figure out a way for the filler. and all the plumbing, external pump, etc.

So what do you all think? Stick with the stock fuel tank and pray for the best, or get to cutting for the fuel cell to keep the weight distribution about the same?
And I've already got the fuel cell and done a bunch of measurements and took pictures, so if any of that is needed let me know.

[afishysilvia]

Once I’m plagued with this I’m going to remove the trunk and put the cell in. Can you move the sub into the back seat since you’re no longer going to have anyone sitting there from the fuel cell being placed there?

I’d imagine when you start cutting the shock tower area with our cars being all stamped together you would be to add some for of framing that would be equivalent to atleast what factory support was.

[silviaks2nr]

Why not plastic weld the tank?

[Kingtal0n]

I found a company that makes a patch specifically for the HDPE material of fuel tanks and guarantees success

https://zilvia.net/f/showpost.php?p=6408288&postcount=8

I've contact companies that plastic weld and they say there is NO WAY they can weld the fuel tank because it is a PEG woven fiber layer encased below HDPE


With the patch from that company there are very specific instructions for it, they are designed for our style of fuel tank materials, it will work if you follow the instructions. e.g. surface prep (sanding), heating (heat gun), drill holes at the ends of the cracks, etc... must be followed exactly

[irish_idiot]

I had this same problem crack along where the straps go on, I took the tank to get it plastic welded at a place called MGM plastics in San Marcos, it temporarily fixed the problem for about 3 weeks before it decided to crack again:(