Brain storming, Fuel tank ideas

morrisman1, Apr 5, 5:58am
looking for about 10-15L capacity. Doesn't have to be alloy, but if steel then nice thin like the factory tanks are. Id like it to fit in the factory position under the rear seat so that i can hook it up to the factory filler and it doesn't have to be isolated from the cabin (not as easy in a hatchback).

Can you think of existing vessels which might be suitable to modify?

clark20, Apr 5, 6:18am
http://www.vpw.com.au/Category/Index/54

Have a look here, also look at boat tanks

morrisman1, Apr 5, 6:24am
Nice tanks, but my budget was more like $100, rather than $500!

clark20, Apr 5, 6:25am
Do you run a surge tank?

morrisman1, Apr 5, 6:29am
I have one there which I can rig up. Is about a 2L capacity

morrisman1, Apr 5, 7:16am
Had a measure up, have about 180mm between the bottom of the seat and the floor pan, so SFA. Might have to cut open the rear seat and make a box around like I did with the other car. That means a tall and narrow tank could be used and eliminate need for a surge chamber.

h.e, Apr 5, 3:48pm
do you need a pump in the tank? If not what about a alloy air tank off a truck. Sure Des Grey motors would have hundreds lying around

clark20, Apr 5, 3:55pm
Why do you want to do this the OE setup is probably lighter than a new one, and with a surge tank no worries with pickup

morrisman1, Apr 5, 4:12pm
I only do sprints in this car, so racing for a couple minutes max. At the moment I need to lug around 20-30 litres just to stop it surging. Quite keen on getting rid of that weight. The factory tank is very shallow and wide, hence the surge. I have some external fuel pumps here so could convert over to a different pump if required. The factory fuel tank weighs about 8-10kg.

clark20, Apr 5, 4:26pm
Remember 15 L less is 12Kg you are saving

Just run it with the surge tank in the engine bay and use a good inline pump, best of both worlds. Then just run minimum amount in the tank.

morrisman1, Apr 5, 4:33pm
or another thought, I could modify the stock tank to be smaller. Reducing its capacity and weight and helping with surge. Get rid of the weight on the drivers side to offset my weight. I have a couple spare tanks I can play around with.

12kg is a lot, there are far more expensive ways to lose 12kg! Im making fibreglass panels and the bonnet saves me 15kg but at a lot of time and effort, doors are about 25-28kg saving each, boot 10kg. Race seat 10kg saving. All up Im saving 112kg, and if I can get another 15kg from the tank then that will be significant. A saving of 127kg total is equivalent to me adding 26hp. I like Colin Chapman's philosophy, but theres only so much you can do to a hatchback.

mrfxit, Apr 5, 4:35pm
Boat tank.
Plastic or steel & made to withstand a reasonable amount of heat & trashing about complete with fittings & fuel gauge

clark20, Apr 5, 4:38pm
I was thinking the same but once you cut and weld, I bet you do not save much, worth a try. Maybe mount a surge tank inside the original tank

http://www.lvvta.org.nz/documents/suplementary_information/HCTM_SAMPLE_Chapter-10_Fuel%20Systems.pdf

extrayda, Apr 5, 4:41pm
morrisman1 wrote:
or another thought, I could modify the stock tank to be smaller. Reducing its capacity and weight and helping with surge. Get rid of the weight on the drivers side to offset my weight. I have a couple spare tanks I can play around with.

Years back a mate got a tank in a falcon modified - I think they added baffle plates inside the tank, and also filled in the wheel well (he wanted more capacity).

morrisman1, Apr 6, 1:18am
Heres what ive come up with. Only cost about $20 of welding supplies and an afternoon, so nothing lost really if it doesn't work. Had to chase some leaks but got them all now. Sneaky beggars they are.

Had I used a TIG welder im sure it would have been prettier but who really cares, Its a budget build race car. I would have had to call in a favour to use a tig while I had a perfectly good MIG sitting there.

http://i264.photobucket.com/albums/ii200/morrisman1/20150405_180230_zpscjsybe3v.jpg

safteystv, Mar 26, 12:07pm
a" mini" fuel tank . or motor cycle one