Will not having the heat shields on the JDM 4-1 header cause any damage? What exactly is their purpose?

 

To keep unwanted heat AWAY from the motor. No damage.

 

If you want to break it down to nit picking, it helps keep heat "in" the header so the exhaust gasses stay hot...and velocity stays up there. % difference when running without a header? Probably negligible.

The other thing about keeping heat "in" (besides "away" from the motor) is away from the radiator and the AC lines (if you still got 'em). The heat jacking up the foam on the AC line is a long long LONG term effect.

If you got the option to have heat shields, run 'em. If not, it's all about HPC or JetHot...

-Geo

 

Thanks Geo!!!