Like the title asks, where best to put it?
Convention would seem to be either side of the seats, or under the seats, or either side of the engine bay above and in front of the rear wheels. I
would like to put it at the front, but it seems a bit risky in the case of a front end shunt.
Any thoughts?
no worse than in a seven in a rear end collision. in fact probably safer in the front of a MEC
as long as you don't put it in front of the wheels, you should be ok?
you say you consider a front end shunt, 7's have the tank at the very rear. that rear end's most likely to be hit by a front end!
edit: like wot he said
[Edited on 12/10/07 by blakep82]
It's true that a 7 could be struck in the rear, but at least that is most likely to be done by a vehicle that is travelling in the same
direction, though obviously not at the same speed. However, a front end collision is more likely to be more serious due to the likely increase in
impact velocity.
That is why I'm thinking that, desirable though it is from the weight distribution point of view, that the front of the car is not really the
place for the fuel tank.
I seem to recall a few middies having the fuel tank along the bottom of the centre tunnel? Centralises the weight, keeps it low, protected from
impact and has minimal affect on weight distribution as it goes from full to empty.
Obviously there is the fire risk of it being directly under your elbow, but I guess a U shaped bit of steel over the top of the tunnel would help?
Mike
exactly at the centre of mass - so with differing fuel levels doesnt have much effect on handling .
so with a mid engine car - just behind the rear seats .
Porche have shoved the tank in the front for ever..... also imps, scoda's etc so nothing new here.
Just keep it inside the wheels if possible
Best place for handling is usually just behind the seats (F1 stylee) as Volvorsport says.
However make sure there is a very good firewall between it and you.
No safety problems with in front of the car, at least no worse than at the back. In a 7 it's behind the rear wheels, so even in front of the
wheels at the front is OK, from a safety point of view, IMO if sub-optimal dynamically..
DAX fit the fuel tank on BEC rush's in the tunnel by the drivers left knee.
regards
Agriv8
Mine's in the front at the drivers side taking up the space opposite the pedal box. One disadvantage of this position is that its behind the rad
and yup it does get hot!! Another disadvantage is I have to take the bonnet off to fill up.
So why put it there? It was the only bit of space left!
By the time cooling pipes, wiring looms, hydraulics and gearchange mechanism were slotted into the central tunnel there was no hope of putting a tank
in.
The space behind the rear bulkhead is full of very hot engine (as it should be) so it went in the front by default rather than design.
It seems that a middi is full of compromises like this.
See also HERE
Cheers
Fred W B
mines in the front for 2 reasons.
1. to balance the weight.
2. so that its not close to the engine and thus heat.
As mentioned no worse than having the tank anywere else and if you enclose it within the chasis then its even safer than most.
quote:
Originally posted by mr henderson
It's true that a 7 could be struck in the rear, but at least that is most likely to be done by a vehicle that is travelling in the same direction, though obviously not at the same speed. However, a front end collision is more likely to be more serious due to the likely increase in impact velocity.
That is why I'm thinking that, desirable though it is from the weight distribution point of view, that the front of the car is not really the place for the fuel tank.
quote:
Originally posted by zilspeed
It depends entirely on the circumstances of the accident though, does it not. You can be unfortunate enough to get smacked up the tail whilst sitting stationary too.
Well in a head on collision I will be much more concerned about what happens to me than what happens to the fuel tank....
A fuel tank will not explode if it is ruptured only leak, yes thats dangerous but not if there isn't anything to ignite the leaking fuel.
I agree that safety is a concern when you are building a car and for mine I have completely encased my fuel tank within the chasis so it would have to
take one hell of an impact to cause signifant damage to it and then I come back to my original point.
In a 7 type car the tank is completely exposed, admitedly its at the back but it would only take a low speed shunt to damage it and seeing it is right
next to the driver thats hardly as safe as mine.... Also the same is true for an Ultima that has no chasis to protect the tanks that are each side of
the engine and thus a small side on shunt could easily rupture them and then get ignited on the hot engine.
Probably the most significant risk for a Midi though is if you roll it as fuel will then get out but the driver may not be able to as often midi doors
open upwards...... I have rolled a sierra on track and stood there while the fuel gushed out at the back of the car (and thus away from teh hot
engine).
Also if you put the tank at the front it is unlikely to be right at the front and therefore there is going to be an element of impact resistance
before the the tank is actually hit... on a 7 the tanks is right behind the rear panel.
For all these reasons I think my tank is safest as far from the engine as possible and within the chasis.
[Edited on 14/10/07 by gttman]
In my mid-engine Mini, I put the 10-gal fuel cell where the transmission would go in a traditional front-engine rear-drive car. The fuel cell is the
red box behind the yellow top battery.
http://www.kimini.com/Diaries/2004Winter/front%20suspension%20in2.JPG
[Edited on 10/14/07 by kb58]
I'm currently looking at going for something like
this
which can be slotted behind the seats.
The safety thing is something will all fret about a bit when deciding the location, but looking the typical 7 and GT40 for example there's
clearly a lot of cars out there that aren't bursting into flame at the slightest bump even though their tank location is far from ideal from a
safety point of view.
Here's a Ford Pinto crashing and burning for all you who've not seen the potential
consequences of a design flaw in this dept.
[Edited on 16/10/07 by Doug68]
Thats a good example as it was unlikelly to be the car behinds tank that caught fire as that would most likelly have been in the rear.
I wonder how many 'kits' out there havn't got an adequate fuel shut of valave that stops fuel being pumped into the engine bay after an
accident?
look up an mr2 they have a tunnel mounted tank. maybe a good donor part?
Grtz Thomas
quote:
Originally posted by thomas4age
look up an mr2 they have a tunnel mounted tank. maybe a good donor part?
Grtz Thomas
I had no idea that's where they were mounted...
All considered.. I think I like the behind-the-seats location. My concept is that the triangulation of the frames at the side is arranged so that there is a clear triangle shaped tunnel across the car. a triangle shaped tank can then be fed in from one side. The tank can fit into a space 1.1m long and say 500mm x 200mm triangle cross section. this gives up to 50 liters. There would be two firewalls, one either side of the tank. This is a very strong part of the car. There may need to be some remote arrangements for fillers and fuel surge, but I think this generally would work well. Controls, coolant pipes, gear shift etc may need to be routed down one side of the car rather than the central tunnel, but since a middy doesn't need a central tunnel and who needs doors.. this is the logical location anyway.
Behind the seats is a popular position in formula cars. I chose a foward position partly to move the CG foward, but also to move it away from my
foward-facing exhaust of the H22 Honda engine. Had I used the later K20A series, with rear-facing exhaust, I may have put the tank where you're
considering, FWIW.
[Edited on 10/19/07 by kb58]
I have space in there in front of the engine due to the rake of my rear buklhead.
Is it not awfully hot in there though ?
I'm saying that in the full knowledge that you are entirely correct in that most single seaters have their fuel tanks behind the driver.
"aweful hot" in where?
[Edited on 10/19/07 by kb58]
Behind the bulkhead at the rear of the cockpit / in front of the engine.
Ah. If the exhaust is on the other side of the block, it's not too bad. Air is an excellent thermal insulator, and you can add a stainless heat shield, too. Also, cooling air can be routed down the center tunnel to help cool the tank, and it's also good for keeping the coolant lines from heating up the center tunnel too much.
like rat a triangular transverse box section across the car constructed from ali honeycomb sheet. Tis virtually at CoG and is wasted space due to drive seat rake...placing the spare wheel is much much harder.
I put my twin tanks in each side pod - not exactly great for side impacts but they are at least within the chassis rails so they have some rudimentary protection.