# THE DE­SIGN PROCESS

NZ Performance Car - - In­side Line -

When de­sign­ing your tank, there are a few lit­tle tricks that will en­sure that it func­tions prop­erly. Sadly, this will re­quire you to be­tray your teenage self and ac­tu­ally use some of that maths you told your teacher you’d never use in real life.

First, you will need to work out the shape. There is no real per­for­mance dif­fer­ence whether it’s round or square; it comes down to per­sonal pref­er­ence for aes­thet­ics or pack­ag­ing. Ev­ery other cus­tom tank in our project car is a cylin­der, so we de­cide to con­tinue this theme. We want around 10 litres, which is mas­sive, but gives us a litre ex­tra over­all ca­pac­ity. The other de­sign re­stric­tion we set is hav­ing a 180mm di­am­e­ter, sim­ply be­cause that’s what size tube we found in the work­shop and we wanted to avoid hav­ing to form a be­spoke cylin­der.

To work out the re­quired height to achieve our 10 litre goal is where that maths kicks in: Π (3.14) x ra­dius (cm) x ra­dius (cm) x height (cm) will give you the vol­ume. Punch­ing in a height of 40cm gives us the cal­cu­la­tion 9cm x 9cm x 3.14 = 10.1 litres, which is close enough to our 10-litre goal. Our fi­nal shape will also have a small sump on the bot­tom that our pumps screw on to, and also a sump on the top for the feed and re­turn to mount to — so the over­all ca­pac­ity is closer to 10.3 litres.

The fi­nal de­sign con­sid­er­a­tion is how the tank will mount in the car. Ours will sit on the base, welded to the fu­eltank cra­dle, and, for sim­plic­ity, we are go­ing to use a large bolt-on pipe shoe, which is es­sen­tially a hose clamp with a mount­ing base at­tached.