Formula SAE Racecar

✓ A safe and robust firewall was designed using a ceramic blanket and Kapton. This design marked the first approved use of ceramics in the competition.

✓ Performed development and qualification standardized tests which received the judge’s approval.

✓ The vehicle was ranked in the top 10 engineering designs, a first for an Israeli team.

Between 2012-2013, a team of 25 engineering students at Ben-Gurion University set out to design a internal combustion racecar as part of the Formula SAE (FSAE) competition. The goal was to be the first Israeli team ranked in the top 10 engineering designs.

I was in charge of the driver’s cabin safety. For this purpose, I designed a uniquely safe firewall.

The requirements for the FSAE firewall were:

1) Flame retardant (will give the driver sufficient time to escape in case of fire)

2) Insulate the driver from heat coming from the engine

3) Protect the driver from small debris impact

4) Impermeable to hot liquids

5) Light weight

I began my design by studying the requirements, brainstorming ideas, and meeting with industry experts in material science, aerospace engineering and mechanical engineering.

I got ahold of a few materials and started testing them for permeability to liquids since the datasheets did not contain such data. The core of the firewall was a ceramic based material while the outer layer was a reflective material.

After measuring the wall temperature on the side of the engine, and assuming a 25 deg Celsius temperature on the driver’s side, a minimum thickness of the firewall can be assessed.

The next stage was getting the design approved by the competition officials. I found a local laboratory which performed standardized collision and combustion tests.

Firstly, a standardized “falling dart” (image a) impact test was performed (ASTM D5420 / BYK Gardener IG-1121). In this test, a weight is released from different heights. Each height represents an impact energy. The weight hits a bolt shaped “striker” which attempts to penetrate the sample. Secondly, a fire safety test was conducted as part of the UL94 flammability standard. The video link can be found here: http://tinyurl.com/small-debris-impact.

Firewall components diagram

The results of the impact test showed that the firewall can withstand an M8 bolt impact with a velocity of 100km/h.

The competition approved the design. The next step was lighting a can of fuel under a firewall sample and measuring the driver’s side temperature change over time:

The test showed a slow increase in temperature which would allow the driver ample time to escape the fire. In addition, the fire did not propagate along the firewall. The safety and robustness of the design were proven.