godfather2

^ +1, now if you're fi then it's a diff story

negcamber

On the heat soak issue...you will definitely see a difference in under hood (bonnet) temps with an unshielded header. I bought a Toda many many years ago, and the heat made a noticeable difference. Enough so that I made my own ghetto heatshield.

For those who want some data...search some of xviper's old threads on what he did to reduce heat soak on his car. He ran several thermocouples in the engine bay to see what worked and what didn't.

Running a car on the track is very different than on the street or autox. Track cars are in motion all the time with air moving through the engine bay to help evacuate heat. In between sessions, you will see drivers letting the car sufficiently cool before they head out again.

On the street, you have stop and go driving where heat just sits and builds up in the engine bay. The header being one of the hottest heat sources in there. Without a shield to protect the intake from radiant heat, you will get heat soak all that much more quickly.

For autox...you have one balls out run and then the car sits waiting for the next run. All the serious s2k autoxers I know pop their hood as soon as the run is over and some (including me) spay cool water on the intake between runs.