[GTsRasta]

1) The ECU is not dynamic enough to take increased MAF signals from increased supercharger airflow and make a perfect new tune for more boosted airflow. If that was the case, we wouldn't need engine management systems. A smaller belt won't just create more air, it'll create more heat as well from the supercharger working harder, thus more hotter air goes into the engine, which makes the engine more prone to detonation. Way different than just taking out your stock airbox, and putting in a cold air intake system, especially at different RPM's and loads on your engine after extended periods of use. So yes, a custom tune would be needed.

3) Lotus offers a Stage II exhaust, so that's a guaranteed power adder that doesn't need to be debated. Headers have been debated here a lot, but PPE and Weapon R both offer dyno proven race headers that won't revert back to the power found in the stock header, no matter how long the header is on. And intakes...are just noisemakers apparently. They have been dyno'd with more power than without, but many will argue it's only temporary.

You can either go with a prepackaged modification and ECU tune upgrade that charlie or forcedfed offers, or you can just upgrade your parts and have a higher state of power delivery with a custom tune on the EFI standalone ECU. Your choice.