Thermal Rejection Competition Spacer: Made from KIYLEX?, a patented revolutionary high-performance final stage polymer. KIYLEX? is as strong as aluminum and can withstand temperatures up to 1100?F. This spacer is designed to insulate the intake manifold from conductive heat transfer from the cylinder head. This thermal barrier reduces manifold temperatures which helps lower Intake Air Temperatures (IATs), improve charge air cooler efficiency, and combats heat soak. CSF is the exclusive distributor for the KIYLEX? Intake Manifold Spacer for the B58 Motor.