In my previous post, I spoke about interior modifications that I made to my 2001 Carrera 4 (996). Today I am going to speak about the performance modifications that I made to it. I will also discuss price and my personal thoughts about the value gained or HP gained. Let's begin by looking at the specs of this car - stock: Source: https://www.autoblog.com/buy/2001-Porsche-911-Carrera_4__2dr_All_wheel_Drive_Coupe/ Let's be honest, the specs on this car (on paper), is not great - 300 HP is quite low for today's standards, but 300 HP for a Porsche is still fast. Without naming names, I know plenty of other car manufactures that were claiming 400+ HP at the time but my Carrera 4 (stock) was faster than them. With a 0-60 time of 4.7 seconds, this car was still pretty fast 20-years ago. The projects that I am going to list below was done over a 4-year time span. So why make any modifications (mods)? For me, the performance mods I made weren't as much about gaining HP as it was the sound. Porsche did not introduce the Porsche Sport Exhaust (PSE) until 2009; therefore, the sound that you heard from my "sports car" was unimpressive. I wanted something more but without a lot of drone. The first mod I made was a K&N cold air intake. As for installation, to the best of my recollection, it was not the easiest thing to assemble. They claim less than 1-hour to install but that was not my experience. The instructions were not great and it took me a few hours to install (note: I did this 10-years ago, and I am recalling it the best I can; also, and they could have fixed a few of the problems since then). Once installed, and I did the cold-start, I could hear the difference. The car seemed deeper and just a tad throatier. The big question, did you notice any difference when you drove it? The answer is NO, not really. I think the sound made it seem like it was a little faster but in reality, it was probably the same. K&N claims on their website, a 8.7 gain in HP https://www.knfilters.com/57-1556-performance-air-intake-system. This could be true, I don't think most people driving a car would notice a difference in 8 HP but some may. As I mentioned before, I feel like it was slightly faster but not by much. I think I paid $270.00 for it but now they are listed for as much as $469.00 If you are looking to buy one: https://www.knfilters.com/57-7000-performance-air-intake-system?msclkid=710b03d810ad159ad9b55c2c9990410c&utm_source=bing&utm_medium=cpc&utm_campaign=US_SN_Shopping&utm_term=4577404348141641&utm_content=All%20Products My next project was the exhaust. I wanted that sound - the sound of a true sports car and thought the only way I could do it was through the exhaust. Being on a pretty tight budget at the time, I didn't have thousands to spend on an expensive aftermarket exhaust so I did my research and found, "FD Motorsports" exhaust. https://fdmotorsports.net/shop/ols/products/fister-996-36-sport-exhaust-modification I decided to do the "core exchange" where FD sends you the new exhaust systems and in return, you send back your OEM ones for a refund. I was not aware however that my OEM was rusted in pretty bad shape; therefore, I did not get a refund and paid full-price for the exhaust, which was $600.00. As I mentioned before, I bought this car in FL and I think the salt down there did some damage to the under carriage so my exhaust and my catalytic converters were both rusted, as I would find out later (I will discuss that soon). As for installation, if I would have done everything that I should have done in the first place installation would have been fairly simple. However, being fairly new to the DIY scene, I failed to order new hardware (bolts and nuts), and broke a few of the old bolts while removing the OEM exhaust. Therefore, I had to keep my car on jack-stands for a few days while I waited on the hardware to arrive. During that time, I decided to get creative and painted the wheel hubs and a few other things in the undercarriage. Honestly, no one would ever see the work I did unless you took the wheels off but I didn't have anything else to do while my car was on jack-stands. Here are a few pics: Once installed, not any noticeable difference performance wise but I finally had the sound that I wanted. The Fister exhaust was perfect for what I was looking for without the drone affect you get from other exhaust. Side Note: I never had my car dyno'd after any of these mods so i cannot verify any of my claims or any of the manufacturer's claims either. Next was the Catalytic Converter (Cats). This was done more out of necessity then preference. I received a Check Engine Light (CEL) about 6-months after installing my new exhaust, which I thought was strange. I rechecked everything around the exhaust and it seemed to be fine. I was not able to locate the problem so I took my car to Hendrix Porsche in Charlotte and had them inspect it for me. They informed me that the Cats were bad and needed to be replaced. Since I was considering installing sport Cats anyhow, I decided to purchase Fabspeed's 200 Cell Sport Catalytic Converter X-pipe (approximately $2,300.00). You can find it here: https://www.fabspeed.com/porsche-996-carrera-sport-catalytic-converter-x-pipe-1999-2004/ On their website, Fabspeed claims an additional 25 HP and, once again, I noticed and heard some difference but I can't verify it was 25 either way. After I installed the CATs, I decided to complete the exhaust system by upgrading the headers as well. As always, I did my research and wanted something reliable but not crazy expensive. As you can see above, my OEM headers are pretty rusty in this pic so I decided to take preventive steps and change them out before they went bad as well. I decided on Agency headers. At the time they were $900.00. You can find them on sale right now for $585.00 https://www.agencypower.com/agency-power-headers-porsche-carrera-996-997-9908-p-24314.html The install was very easy and a perfect fit. I actually installed these a few weeks after having shoulder surgery on my right arm for a torn rotator cuff and bicep. Yes, I could barely raise my right arm and was able to still change the headers out by myself. This time I learned my lesson however and bought all the hardware and gaskets along with the headers. After the complete exhaust system modification (headers, cats, and exhaust) I could honestly say, my car sounded exactly how I wanted it to sound. In my opinion, it sounded like a sports car. I could also tell a small difference in the performance as well. I wouldn't say it was a lot faster but there was a noticeable difference. I did three other projects to trying to increase the performance of my car. These were the IPD plenum, GT3 Throttle body and an ECU tune. I don't know if I would recommend the IPD Plenum or the GT3 throttle body. If you are curious about those two, you can read about both of them here: https://www.ipdplenums.com/products/plenums/carreras/996-carrera. . The idea behind this is, improve the airflow going into the motor and back out as well (seems ).. As for the tune, I went the Softronics performance software tune: https://www.softronicsoftware.com/996-carrera-performance-software-00-04/ After all the modifications that I made to my car, I figured an ECU tune is now in order. The tune cost me $895.00 and was a DIY tune. Basically, they mailed me some software that I downloaded onto my computer, I then hooked my computer up to my laptop, sent them my current mapping system and then they responded with the recommended tune. It was fairly easy and they were readily available to assist with any problems. I did have to call them for something but I don't remember what. The question becomes, would you do it again and was the performance aspect worth the cost? I would have to answer yes and no. Yes because I enjoyed working on my car learning how to do new DIY projects. Plus, I had the added bonus of knowing that my car was in good working order. I did not experience any CEL lights throughout this entire process, other than when my OEM Cats stopped working. As far as the "no" answer, I don't think the amount of HP you get is worth the price. If I would have just saved the money each time, I could have traded my car in plus the 15 Grand that I spent on modifying the car and bought a Turbo. Not too far from my home, was a 996 Turbo selling for 39,900.00 - that would have been the logical thing to do. As I said before, I loved working on that car almost as I loved driving it. 996s may not be the most popular 911 but I loved my 996 and it will always have a special place in my heart. If you are considering buying a Porsche and you are on a budget, I would consider buying a 996. It truly is a driver's car.