Reducing the capacity of the stock fuel tank.

I've been toying with the idea of modifying the stock fuel tank as the stock capacity of 70 litres is really a bit much for a dedicated track car.

I haven't given it detailed thought yet as I haven't inspected the actual tank. The idea is to remove the tank, after draining and purging. Cut the tank around its circumference and fit a flat piece of steel (perhaps ever so slightly conical in shape, to allow fuel to gravitate towards the centre) to the top section of the tank. To the now halved & flat(ish) bottomed tank I would fit a small cylindrical extension to the underside to accomodate the fuel pump and pick-up pipe.

I think this extension piece might also work well as a constant fuel supply (is there a proper term for this?) to the pump when the fuel level drops, even under hard braking and cornering as the fuel would drop into it and wouldn't be able to escape.

I know the fuel level guage would be all but redundant but if I halved the capacity would it not stand to reason that when the guage approaches half way I know it's time for a refill.

Thoughts?

Has anyone tried this before?

I don't really want to fit a custom tank in the boot as that meand firewalls and new fuel lines.

I take it you didnt know the fuel tank is plastic then?

Be easier to pick yourself up a race tank wouldn't it mate?

I take it you didnt know the fuel tank is plastic then?

Just found out!

Be easier to pick yourself up a race tank wouldn't it mate?

Looks like it now.

Plastic can be welded to , we do it all the time, just not for petrol tanks.

For some reason the new welds and fuel don't go together

Plastic can be welded to , we do it all the time, just not for petrol tanks.

For some reason the new welds and fuel don't go together

Do you mean the welded plastic joints react badly with the fuel and start to leak?

I was actually looking at a plastic welding kit online, I'm still toying with the idea of taking a sizeable strip of plastic from the circumference of the tank and welding the top and bottom back together.But are you of the opinion that this wouldn't work?

http://www.harborfreight.com/plastic-welding-kit-with-adjustable-temperature-96464.html?utm_campaign=SEO&utm_medium=Inbound_links&utm_source=linking

Seems like a load of agro to me, just fit something like this plastic 5 gallon fuel cell?

http://www.summitracing.com/parts/SUM-290101/

Seems like a load of agro to me, just fit something like this plastic 5 gallon fuel cell?

 

http://www.summitracing.com/parts/SUM-290101/

Yeah but then you're into a new pump, sender and all the plumbing that goes along with it Jamie. More flippin' money.

Plus I think putting a different fuel tank on the car bumps it up to the unlimited class of the Irish time attack series where the full-on race cars compete. No ta.

I thought I could be sneaky and have an OEM "looking" tank to stay in the lower class.

Dont put so much fuel in

Dont put so much fuel in

Now why didn't I think of that!

I never fill it more than halfway Jonny, but that leaves an awful lot of room for the fuel to slosh about. Which can lead to various problems. Engine damage being one. Crashing being another.

Just fill it with pour in foam baffles mate.

http://www.demon-tweeks.co.uk/motorsport/fuel-tank-baffles

Just fill it with pour in foam baffles mate.

From a safety point of view those baffles would be no harm to have, regardless of what I do to the tank.

Is the area around the pick-up and the sender arm/float left open while the baffles are packed into the surrounding tank?

I can see how that would work with the foam options but those little aluminium cylinders would foul the sender so they aren't a runner.

But another reason for reducing the actual size of the tank is so I can do something similar to this to the back of mine.

I say similar because I think that the above car is space framed, but I could achieve something mildly similar if the tank wasn't hanging down so low with a bit of a trim to the rear bumper.

Probably something more along the lines of this:

Do you mean the welded plastic joints react badly with the fuel and start to leak?

 

I was actually looking at a plastic welding kit online, I'm still toying with the idea of taking a sizeable strip of plastic from the circumference of the tank and welding the top and bottom back together.But are you of the opinion that this wouldn't work?

 

http://www.harborfreight.com/plastic-welding-kit-with-adjustable-temperature-96464.html?utm_campaign=SEO&utm_medium=Inbound_links&utm_source=linking

We use a somewhat similar device, and an air blower for welding.

But in my experience, the welds won't hold, and I would not mess around with a unreliable fuel tank:eek:

We use a somewhat similar device, and an air blower for welding.

But in my experience, the welds won't hold, and I would not mess around with a unreliable fuel tank:eek:

Yeah, it is a gamble alright.

That why I'd be happy to pay a professional do the reassembly, if it was indeed possible.

But from your experience, to which I must bow as I have none, the idea is a bad one.

DAMMIT!!

have you looked at race cells?

there loads companys make them.

have you looked at race cells?

 

there loads companys make them.

Have you read all the posts ?

Have you read all the posts ?

i asked again as i cant see a reply to someone else asking so it may been missed or over looked

Yeah but then you're into a new pump, sender and all the plumbing that goes along with it Jamie. More flippin' money.

 

Plus I think putting a different fuel tank on the car bumps it up to the unlimited class of the Irish time attack series where the full-on race cars compete. No ta.

 

I thought I could be sneaky and have an OEM "looking" tank to stay in the lower class.

it has