Fuel Tank Over The Diff Cage?

[brainbug007]

Just wondering is anyone else has put their tank over the diff cage or knows if mr IVA will be ok with this? I know it says in the IVA manual that if it where to leak, it can't find a way into the passenger compartment which in theory it could but I would have thought it would be unlikely. Plus if the tank is the traditional location, can't the fuel in theory find it's way into the passenger compartment the same way by tracking along the bottom of the diff cage and onto the seat back rails which it could then in theory go thru the seat back bulkhead?

[Talonmotorsport]

My understanding of this is you can't have the tank mounted in a place that it might pool if fuel is either spilt or leaks, this would mean you can't fit the tank in a sealed boot space or say in the passenger foot well. As the roadster does'nt usaly have a closed bottom to the rear suspension cage you can fit the tank any where around it.

[K4KEV]

I'm already going that way......I would not put the whole tank volume above the diff cage as you will raise its centre of gravity and loose a little stability ....the lower you keep EVERYTHING, the better your car will handle


http://i465.photobucket.com/albums/rr12/gfowa/Haynes%20Roadster%20build/DSC00005.jpg

[ayjay]

did you forget something :o

[Jimmyd]

I think you could class that as a long range fuel tank!!

J

[Cyberbeej]

Cool tank, what kinda volume does it work out at?

[tex]

Just wondering is anyone else has put their tank over the diff cage or knows if mr IVA will be ok with this? I know it says in the IVA manual that if it where to leak, it can't find a way into the passenger compartment which in theory it could but I would have thought it would be unlikely. Plus if the tank is the traditional location, can't the fuel in theory find it's way into the passenger compartment the same way by tracking along the bottom of the diff cage and onto the seat back rails which it could then in theory go thru the seat back bulkhead?


should be alright - the westfield FW bodywork has the tank above the diff due to the curved corners of the rear tub. also has another advantage - in a rear end shunt the tank is further away from the rear with more chassis to mash first. if your gonna do that i would make my own crash cage around the tank to help even more if you can. more the better.
there is one draw back tho - tank size will be smaller than normal position tanks - less range - more hassle when touring etc.

but less weight...

a good design should include a filler cap that isnt attached to the fibreglass bodywork - if you have a filler cap that is fixed to the fibreglass if you get hit it could rip off the filler cap leaving the filler neck wide open to fuel sloshing out. by fitting a screw cap to the top of the tank and not in anyway fixed to the bodywork you will make the car much much safer. just make the filler neck right center top of tank with a hinged lift up lockable boot panel. you can buy key locks from CBS for next to nowt. using a cam lock i had 2 before on the boot box on the rush, chromed [look like they are off a locker]

[Wynand]

For safety reasons I fiited my fuel tank over the diff. Having it a fair distance from the rear tub sheeting buys some peace of mind should someone smashes into the back of the car...

I could have made the tank larger (wider) but the 34lt capacity is OK for me and should have a decent range. On the bottom of the tank is a pickup sump with a 16mm drain plug fitted.
The filler is under the bootlid, yes you read correctly, my car has an opening bootlid that sits level with the top of the roll bar bases. A bit of a hassle to fill, because one has to get out and open the trunk, but also gives one a change to look over the suspension for any problems when taking on fuel.
Btw. my chassis is a McSorley 442E.

http://img.photobucket.com/albums/v305/wynand/Lotus7Tank.jpg

[leroybrown911]

Just found this thread as I am soon going to start fabricating a fuel tank and I also want to put it over the diff cage, or even extend the original design up in to this space.

Does anyone have any dimensions or pictures of how much space there is? I do not have my bodywork yet so I have no idea how much room there is or whether I will need to cut any of the fibreglass to make it fit? (I am using a fibreglass rear tub)

[leroybrown911]

I can explain why I asked for any pictures and clearly there are somereal good ones already in this thread. :o

I was looking through the posts on my work laptop (in my lunch of course!) and for some reason that PC did not open the pictures already included in this thread. Now at home and I can see there are some great photos that are fine for me to work with.

Very embarrassing!

[TSM Locost]

To keep the center of gravity as low as possible i have left out both D13 and have a tank 950mm long giving approx 9 gallons, enough for over 250 miles.
The bear braces from the rollbar are attached to plates in the corners of RP1.