I had an aluminum pipe on my SPI for about 6 months until the rubber neck broke and I put a stock plastic pipe back on. I use a Ractive cone filter with no heat shield and I have to say it works great. I didn't notice any differance betwen the chrome and plastic tubes as far as heat and power loss. My wife has the Ractive filter w/heatshield on her '04 Elantra GT and I feel no differance between heatshield and no heatshield. I do feel a differance with the heat only with dramatic changes, kind of like "night and day". Just my 2 cents on the subject.