fiberglass rear tub frame Q and fuel tank

[baz-r]

got a bit of a question im thinking of mounting my fuel tank behind the diff/rear support across the back as some other seven type cars (zero) to create an area that can be used as a boot and have a larger tank to have a good range (40l) as i plan to do abit of touring when its finnished.

i need to know how far off the grp frame comes to the back of the tub and how it is affixed to it i have the grp tubes and thair ready to fit.
i was thinking if sitting the tank on top of them and reworking the two d tubes that tie it all in.
would love to hear what everyone thinks and any issues that i havent thort of?:o

my chassis is at the point where i have all the main bits in up to the rear support fixed to the seat back and im not fussed what type of rear end i have
but i need to start to design and build my tank and still be able to fit it inside of the std back end

i have also thort of using a tank from a std car to save building a tank any ideas what would be a good car too look at
i think someone said mini van tank could be used? anyone?

[davedew]

Baz,

Attached is a drawing showing the original rear end & the grp rear end frame overlaid on each other. The outline of the tank is the actual one fitted to Gus's car which holds roughly 40 ltr.

If you need any further information give me a shout and I will see what I can do.

Cheers

Dave

[baz-r]

thanks dave as i hoped the grp frame will fit inside the metal back end
im thinking of using the grp tubes to support the bottom of the tank ditch d13's and affix the ends of the grp frame to the two dignals behind the suspension arms/arch
so i can have a tank aprox 990 long and of std hight maximising boot space as well as tank space :rolleyes:
also joining the dignals off the back of the roll bar to the top off the tub rails for extra support
i think it will work out about 50% bigger than the orignal and leave just as much room as std tank :)

[HandyAndy]

also joining the dignals off the back of the roll bar to the top off the tub rails for extra support


Forgive me Baz, but I don,t understand this bit of what you intend to do :confused:

The only point I would make is that if you ditch the D13,s & increase the capacity of the tank along the rear GRP1 tube then that would create alot of unsupported weight with a full tank, or maybe i,m not understanding your suggestion of the rear layout?

The tank on my car is only approx 10mm away from the GRP tub.

cheers
andy

[pradaloup]

you can mount a tank Renault 18 sedan

[baz-r]

Forgive me Baz, but I don,t understand this bit of what you intend to do :confused:

The only point I would make is that if you ditch the D13,s & increase the capacity of the tank along the rear GRP1 tube then that would create alot of unsupported weight with a full tank, or maybe i,m not understanding your suggestion of the rear layout?

The tank on my car is only approx 10mm away from the GRP tub.

cheers
andy

andy im using the grp tubes to hold the tank not the grp tub not cp8 then not fitting d13 that get in the way of the tank then tieing in the ends of grp1 to the two tubes that come down dignaly from the rear shock mounts.
plus tieing in two supports down off the roll bar to the top of the rear top rail of the back end (linked to the bottom rail)
most likely not going for a grp back end but could be done i think

ps run out of tubes now all fitted a dream:cool:

[HandyAndy]

I,ve just been re reading this thread & think I now understand your suggestion Baz....

Is this what you mean?........

To have a tank sat on 3mm plates spread across the gap between RS14 & The GRP1 tube?

To remove the two D13, diagonal tubes? & extend the tank along the length of the GRP1 tube? ( width of the car )

To attach the GRP tub to the diagonal tubes ( I presume you mean D11,s) behind the suspension boxes?

To join the back brace bars of the roll bar to the top of the GRP tub support rails?

If this is your plan........By removing the 2 D13 diagonals then the only thing supporting the tank would be the 3mm steel plates (CP8,s) & the 2 spars GRP2,s & the long spar GP1, this wouldn,t in my opinion give enough vertical support to the tank.
With regard the back braces from the roll bar to the upper tub support rails......when using a GRP rear tub there is no upper support frame for the tub so the back braces from the roll bar need to go from the roll bar all the way down to the chassis base rails ( in my car a steel plate welded in between RS14 & GRP1), tho this would give the tank position in your suggestion alot more support.

If you intend to use the "Book Spec" tank dimensions, just be aware that it won,t fit when using a GRP rear tub.

Sorry for the waffle/ramble, just trying to understand your suggestion, it would work if you took the roll bar back braces all the way down to the chassis rails to a steel plate between RS14 & GRP1.

Hope I make sense? :o

cheers
andy

[HandyAndy]

oops, we,ve both just posted at a similar time, I must learn to type faster :D

Nice to hear your flat pack kit has gone together nicely, would be great to see some piccies :)

cheers
andy

[baz-r]

thats about the jist of it andy :D
i think a grp back end could be a problem as without having one sat infront of me it would be hard to tell
having a look at what other 7 reps have thair tanks held in buy (not that much) i dont think its going to be to much of a problem
also i dug out a few build dvds (other 7's) to see how thay fit them in

i plan to metal strap my tank to the back of the rear support that looks over kill to the other cars i have been looking at tho some have the diff on rubber bushings.

this reminds me i must get into drawing progs and stuff to be able to post up better info :o
and ply john from 3ge with more biscuits/cakes to come and take a look and see what he thinks :rolleyes:

[3GE Components]

and ply john from 3ge with more biscuits/cakes to come and take a look and see what he thinks :rolleyes:

Or beer, as a last resort Barry :D

Kind regards

John

[baz-r]

didnt think you are alowed beer john

[baz-r]

update worked out rough volume and worked out how heavy a ful tank would be

looks like it would be 45l ish and be 33kg of fuel

[baz-r]

just an update on my tank
i have started to make a tank in alloy and its working out abot 35l
its a chopped down streched version of a grp tank

my tank allows a full boot space as its the same height as the top of the diff box and now the unneeded d13's ar gone and grp frame in (2mm wall box) i have sortend my tank to 800mm so i have room at sides to get roll bar ties in and space for fuel pumps and stuff if needed

i think the grp frame would be strong enough on its own as i can jump up and down on it and its lifting the front of the frame of the build board and im 11st