Hard brake lines
 

I have a question about hard lines when plumbing a race car.

It's easy to run to the auto parts and buy standard Dorman line or AGS Nicopp. There are also quality stainless lines that seem pretty a-ok.

What is the best? Like, what would an Indy Car use? Or a Monster Energy Cup Car? Or a Daytona prototype?

-- Ramey

Ramey - brake systems work and feel better when we reduce system compliance. Things like rubber lines can expand with heat and pressure, so they don't have a consistent feel across the performance range.

In motorsports the gold standard is a stainless steel braided flexible line that connects from the car's OE hardline to the caliper. These do not expand like rubber lines and help to provide a more firm pedal feel.

Other areas of system compliance are in the caliper itself - it can be flexible and, "clamshell" as it exerts braking force on the rotor, which effectively reduces the system output as compared to a non-compliant system. The firewall is another area that flexes behind the booster; master cylinder braces are sometimes used to reduce firewall compliance.

The benefits of all of these things add up to higher brake torque output, better pedal feel & modulation and pad release characteristics. The stainless brake line is usually the easiest component to improve due to cost and skill needed to install but the caliper itself is usually a much larger contributor to system compliance.