[sherrferris]

If your like me and have a turbo it doest matter how hot the air coming in is, its going to be really hot by the time it comes out the turbo, so dropping the filter somewhere inside the engine bay is fine. Get a good intercooler and let it do its job. as for most other cars the cooler air will make a bit of difference, but you will gain just as much by doing a mod to the air temp sensor to trick it into thinking its always cold outside, which causes it to advance the timing a few degrees. Only real downside to this on the majority of cars is possible knocking in the summer when it gets hot, but you can resolve that by running a higher octance fuel. If your car relies on the temp sensor in any way to engage the secondary air injection system to help warm the car up to operating temp (primarily needed in the winter in colder environments) then this can also cause problems.

as for the heat wrap for headers, I dont suggest doing that at any point in time ever on headers. While it will result in your headers not putting as much heat into the engine bay, in time this will just result in excess condensation building up between them and the header when the car is shut down as the car cools down. In an exposed header this condensation doesnt form because its too hot and it evaporates. When wrapped it usually results in bad rusting over time. If you really want to get rid of the heat in the engine bay get a good set of headers that are ceramic coated inside and out. Less heat and more performance.

People tend to want to knock lots of little mods you can do to a car that gain 2hp at a time, but if you do enough of those mods then they add up eventually. Other things that can help are bypassing the coolant line that runs through the throttle body, filing down the egr valve if it protrudes into the head of the car, removing any form of vics or vcts (or whatever name your car uses) if present this is the system that allows your car to swith from the long runners to short runners on the head of the vehicle at different rpm's. Needed on most cars to provide good low end torque, but just interfere with air flow and cause turbulance in the airflow on a well modded vehicle by often as much as 30%, port and polish the throttle body, on some engines such as the ls1 you can swap 2 of the coil packs around (I believe the #3 and #8 but could be wrong) and this provides a measurable and some say noticeable gain. I say completely avoid these stand alone tuning boxes like the ones hypertech sells, or any kind of piggy back unit unless you are trying to get the most you can out of a completely stock system. The only kind of vehicle these truly work well on are diesels. Otherwise take it someone and get a proper tune or buy the software and cables for a laptop and learn yourself (this is what I have done). Someone that knows what they are doing can mod your vehicle well based only on the mods done to the vehicle, and few good hard runs up and down the track (aka the road in front of your house). And ask the person if the tune makes usable power or makes dyno power. a lot of people are good at dyno tuning only to find later your car runs like crap on the road.