Longer range fuel tank(s)

[Talonmotorsport]

While siting on the thinking chair waiting for the penny to drop I was thumbing through mini mag and came across replacement fuel tanks. In the 'real' mini as in Austin the tank sits in the boot in the corner and still leaves room for a pair of spare pants and a tooth brush much like the Roadster. This got me thinking what if you had another two fuel tanks that sat either side of the main tank still leaving a small boot space? They would sit between D13 and the curve of the rear tub. If they where plumbed in low with shut off valves between the tanks, you could run round using just the main tank and when you go touring open up the valves and have another 16+ ltrs to play with. You would need vent pipes between the two outers and the main other wise it will not balance, and when the fuel is low again shut the valves.
Can any body see any potential problems with this idea besides added weight?

[fabbyglass]

Weight the big issue and I reckon the worse thing that folk do is use steel to make the tanks out of, there isn't much if any rear end protection in a 7 so the tank should ideally be made from something that wouldn't spark if clouted...ali with that explosafe foamy stuff in it.

[Talonmotorsport]

how strong is a fibreglass rear panel with the tank sat right behind it, does it meet euro N cap safty standard 1?

[fabbyglass]

[QUOTE=Talonmotorsport;50331]how strong is a fibreglass rear panel with the tank sat right behind it, does it meet euro N cap safty standard 1?[/QUOTe


Kit cars are not would I would describe as an "ideal car to crash in" wherever the fuel tank is or whatever the body panels are made from....:rolleyes:

[Talonmotorsport]

I absolutly agree with that so what difference does it make where the tank(s) go, I spoke to some one who was concerned about the lack of a crumple zone on the rear and he decided to buy an MX5 instead. The foam that goes in the tank is that not to stop fuel 'slosh'? Given the size and shape of the fuel tank if it's been made with baffles it should be the strongest fabricated part of the car in theory?

[TSM Locost]

At least one person on here has mounted his tank above the diff on the rear suspension frame. I cant see how you could get much safer than that. The downside is that it raises the centre of gravity.

[georgenewman1]

While siting on the thinking chair waiting for the penny to drop I was thumbing through mini mag and came across replacement fuel tanks. In the 'real' mini as in Austin the tank sits in the boot in the corner and still leaves room for a pair of spare pants and a tooth brush much like the Roadster. This got me thinking what if you had another two fuel tanks that sat either side of the main tank still leaving a small boot space? They would sit between D13 and the curve of the rear tub. If they where plumbed in low with shut off valves between the tanks, you could run round using just the main tank and when you go touring open up the valves and have another 16+ ltrs to play with. You would need vent pipes between the two outers and the main other wise it will not balance, and when the fuel is low again shut the valves.
Can any body see any potential problems with this idea besides added weight?

i was wondering the same thing, i was going to put a tank either side and use the middle as a large boot, but then decided against it as i didnt want to try and test mr iva, i was going to use a couple of emptu fire extinguishers that i found in a skip as the tanks to sit either side of the diff, might still do it after the test tho :)

[AshG]

funny you should mention that talon as it is exactly what i am doing. im having one side as a reserve tank and the other as a my swirl pot

[baz-r]

why not jus make a larger tank making it longer across the with of the car?
you should be able to get a good extera 65% volume easy

[AshG]

i spoke to chris about removing the 19mm supports that go down to the back of the tub to get a bigger tank in he advised that they are mega critical to the strength of the diff and suspension box at the back and it would be very unwise to remove them. he said he would look at a solution if i really wanted to remove them but im not too bothered as i need a swirl pot anyway.

[Talonmotorsport]

I think d12 defo needs to stay otherwise all the rs cage has no bracing, I think baz ment removing d13 to make more room. If my posts seem short the power pack on the lap is dead I'm using the ps3 which is slow without a key board.

[AshG]

d12 and d13 work as one piece im leaving mine put especially with the power im planning to stuff up its backside. each to their own though

[fabbyglass]

i spoke to chris about removing the 19mm supports that go down to the back of the tub to get a bigger tank in he advised that they are mega critical to the strength of the diff and suspension box at the back and it would be very unwise to remove them. he said he would look at a solution if i really wanted to remove them but im not too bothered as i need a swirl pot anyway.

Take a swizz at the rear end of the Striker.....not much there yet one of the best kits out there and why so many get used for racing.

[AshG]

completely different rear end design though mark. on the striker the wishbones mount to the triangular frame which supports the back of the car and the diff hangs off the seat back rails. on the roadster the rearbox that supports the rear weight of the car hangs off the same spot on the seat back rails as the diff. d12 and d13 spread the weight up to the upper seat back rail and the suspension turrets taking some of the strain off the lower seat back rails.

horses for courses but if d13 wasnt needed it wouldnt be there simples as that.

btw haynes validate all the designs before going to print so its been well scrutinised for strength. the single seater is already on its third revision due to input from haynes

i dont disagree with you mark the striker chassis as a proper bit of kit but its pushing the boundary and is a bit risky for an inexperienced home build, the roadster was designed for home build and as such was well over engineered to compensate for poor welding and construction.

[georgenewman1]

i dont have a copy of the book on me at the moment, but when you run a fiberglass rear end everything is cut off from the diff cage back im assunimg not reducing the strength, so would it not be possible to remove the two 19mm diagonals that go from the diff cage to the bottom of the rear tub hoop and just have a long tank in there with many baffles?????? just wondering

[HandyAndy]

i dont have a copy of the book on me at the moment, but when you run a fiberglass rear end everything is cut off from the diff cage back im assunimg not reducing the strength, so would it not be possible to remove the two 19mm diagonals that go from the diff cage to the bottom of the rear tub hoop and just have a long tank in there with many baffles?????? just wondering


When fitting a GRP rear tub, the only parts from the original "Book Plans" that are removed are RP1, RP2 & RP3,s, (basically the round tube framework),

The parts D13,s are still used, tho are a slightly different dimension that then are attached to a 99cm length of 25mm box tube(known as GRP1) from the original mounting position on the diff cage,there are also 2 new lengths of 25mm box tube (known as GRP2,s,) welded into position from RS14 to the new GRP1 part,
so the strength is still there as per original "Book Spec", just without the round tubes that would normally support the Ali tub, as the GRP tub is "in a way" self supporting & attached to the chassis along the base of GRP1 & to D11,s & D9,D10.

cheers
andy

[fabbyglass]

Ash,
How close is the single seater now? has it been run yet? busting to see what it looks like...:cool:

[AshG]

last time i spoke to chirs he was looking to iva it in jan. could be a bit delayed though as he has been poorly again.

[baz-r]

When fitting a GRP rear tub, the only parts from the original "Book Plans" that are removed are RP1, RP2 & RP3,s, (basically the round tube framework),

The parts D13,s are still used, tho are a slightly different dimension that then are attached to a 99cm length of 25mm box tube(known as GRP1) from the original mounting position on the diff cage,there are also 2 new lengths of 25mm box tube (known as GRP2,s,) welded into position from RS14 to the new GRP1 part,
so the strength is still there as per original "Book Spec", just without the round tubes that would normally support the Ali tub, as the GRP tub is "in a way" self supporting & attached to the chassis along the base of GRP1 & to D11,s & D9,D10.

cheers
andy

my plan is to make a longer tank ditch d13 (i think thats the name of the bottom 19mm tube from diff cage to lower round tube) use grp frame to hold the tank and still fit a metal back end there was only two little strips of metal there witch now have been replaced buy a nice box frame to hold the uprated tank.
there are other ways to put d13 strength back in but as its all tied into the roll bar anyway i dont think theres much to worry about.

[robo]

Stirring up an old thread. No one has mentioned actual capacity here,how much does the standard tank hold? Has anyone built a bigger tank?

Bob

[gus]

The book tank holds 25lt. The tank i made for mine is 35lt, it is just a taller version of the book tank. there is a drawing on the forum for it.

[K4KEV]

intending to make mine from 3mm ally/twin baffles/swirl pot and 60ltr cap by going over the diff as well like an inverted L

[robo]

intending to make mine from 3mm ally/twin baffles/swirl pot and 60ltr cap by going over the diff as well like an inverted L

That sounds more like it. It would make me a bit nervous embarking on any trip with 25ltrs of fuel. You are probably a bit closer to building your tank than i am, would be interested in your design.
Bob

[robo]

just had a thought. 60 ltrs of fuel is about 42kgs hanging on the rear of the car. Do you think the suspension would cope?

Bob

[K4KEV]

I am fairly confident it would cope easily as it is a beefy set up and the protech
shocks I have are adjustable +apart from the fact the extra weight for me will be a bonus as my engine will be putting out 200+bhp:D and I will need that extra grip.

[baz-r]

i have built a 35l ish tank from 2mm ally that is level with top of the diff frame and sits on a grp frame by ditching d13 i could make it simply longer
i think the grp tube work is strong enough without d13 im 80kg and i can stand on the tip of it and jump up and down with no bending or movement
the hole idea was to keep a full size stowage area in the back and get a bigger tank so touring would be possible :D
if you have a metal back end then you would need to redesign the support as the orignal only has two thin strips of metal and d13 that support the backend

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