I'm working on a build for NASA TT, and I'm trying to figure out the best way to boost power up to my class limit. Here is some information about the car and my restrictions for adding power: The only modifications I currently have to add power are the Ford Racing Power Pack (K&N filter + Ford Racing tune), and I've replaced the mufflers with Borla S-Types. Aside from an aftermarket driveshaft, everything else is stock. It consistently makes ~365whp peak on a Dynojet. Based on my build, I can make about +35whp and stay class-legal. If I make more power than that, I'll either have to detune or use smaller tires (which actually might be worth trying). To fully take advantage of the new rules, I should increase my redline to at least 7100 rpm. However, I'd rather not go much higher than that if possible since I don't want to compromise reliability. I've been taking this car to the track since I bought it in 2011, and I've had absolutely nothing go wrong with the engine; I haven't pulled a single spark plug or valve cover. Not including a tune, my budget is ~$2000. I can do all of the work myself (besides dyno tuning), so labor cost isn't an issue. While this is a dedicated track car, it's still street-legal, and I still drive it to events. Therefore, I don't want to delete the cats. Also, I live in a townhouse development, so I'd prefer not to make the car much louder if I can avoid it. Furthermore, this means I'll be using 93 octane pump gas since E85 and race gas are impractical for me. I've done a lot of reading online, and here are the two options that seem promising: Long tubes with high-flow cats. I've read forum posts and articles in which people claim anywhere from 15 to 30 whp just from long tubes, so I don't know how much to realistically expect. I know that 35whp is very unlikely, but something close should still be good enough for most of the season. I really doubt that a $350 cold air intake will be worth much, but it might close the gap a little. Since most designs are not fully enclosed, I wonder how much IATs and flow restriction increase with the hood closed (on track) compared to the OEM intake system. I looked into combining long tubes with a Boss 302 intake manifold, but that doesn't really seem worth it unless I'm revving to 7500 rpm. "Stage 3" camshafts. I've seen "NSR" camshafts that advertise decent gains up to 7200 rpm, but I'm a bit skeptical that the OEM valve springs are really appropriate when I'm beating the crap out of car for 2 hours over the course of the weekend. I've seen +50whp reported with "stage 3" camshafts requiring valve springs, but that engine also had aftermarket intake/exhaust parts. I'm not sure how much less I should expect with basically OEM intake/exhaust. What do you guys recommend? Does anybody have experience with before/after dyno testing either of these combinations? Thanks in advance.