Back in february of 2000 I bought a stock 968 from the original owner. I spent the first couple of months fixing those little things that most new owners tend to address�but eventually my thirst for updates and power urged me to pursue different tuning options. I�d be introduced to David Chen that summer by a buddy of mine with a 968. David Chen has done a full exhaust, m030 suspension, cams, and other things to this owner's car.
I decided that I wanted to start with exhaust so I spoke to David on the phone several times discussing options [at the same time learning a lot about the 968] and he suggested a simple Borla muffler using the factory piping and factory tip. He intended to suggest things that gave me the best value for my dollar. He ordered the Borla muffler for me and I took it to a muffler shop that he recommended to have it installed on my car. The installation was quick and inexpensive. I drove the car home and noticed better revving in the mid and high RPM�s, but most importantly it sounded the way I wanted it to sound�bit of a V8 rumble at idle and a literal scream above 5k RPM�s. Driving through a tunnel at 5500 RPM's in 3rd gear was absolutely unreal!
Several months passed and I got the itch to modify the car again. SFR had made some posts on Rennlist about their upcoming supercharger kits followed by an offer to some lucky Rennlisters whose cars would be used as test beds for SFR performance tuned chips. I jumped at the opportunity and got in touch with John Anderson. He seemed enthusiastic about us coming down to take part in the chip tuning so they could offer this software on the market. We met John at the dyno shop one morning and saw his black 87 944 turbo�I left my car at the dyno shop and Tim Richards [founder of Speedforce Racing] came to pick me up. I asked Tim how he got started in the tuning business and he went through the whole story�seemed like a genuinely nice guy.
I stuck around for a few days waiting for the tuning of my car to be completed. I was actually sort of nervous because the car would spend lots of time on the dyno in order for the software tuner to get the chip just right. My car had a lot of miles on it and so I also worried that the engine compression might be low and reflect in poor horsepower and torque numbers. I felt like I was waiting to find out if my kid was going to be a male or female, I was very anxious. I kept in touch with John and Tim about the car and they would often check with the dyno shop on progress with tuning my car. The software was being difficult and it turned out the shop didn't have the correct program to break down the code so we waited a few more days for the program to arrive.
They were able to tell me what the initial dyno results were. 198 RWHP and 190 RWTQ with 172k miles on the engine. This stacks up very well with other 968's which typically dyno between 195 and 205 RWHP and 180 to 190 RWTQ. I was very glad [and relieved] that my 968 engine was making good power. Even with high mileage the cylinder head must be in good condition and the piston rings must be holding good compression. My car also had the 951 transmission which David Chen installed 6 months prior, meaning my car could've made more power on the dyno had it still been equipped with the factory 6 speed gearbox. My 968 was dynoed in 4th gear assuming a 1:1 drive ratio when in fact the 944 Turbo 4th gear has a 1.034:1 ratio and the 968 4th gear has a 1.111:1 ratio. Doing the proportion my car could hypothetically have made 212 RWHP and 204 RWTQ!
Eventually I would receive the call that my car was finished. Exciting news, John told me the engine made 7 more horsepower and lb-ft of torque everywhere in the RPM band. It doesn't seem like a significant performance increase on paper but Porsche is known for getting things right at the factory...improving upon that is pretty exciting. So Tim picked me up and gave me a ride back to the shop to pick up my car. They felt bad about the delay in getting my car back [the tuning process ended up taking nearly 2 weeks] so they gave me a set of braided steel fuel lines to replace my original rubber ones. This gesture was more than fair and they even installed them for me.
Actually, it's a funny story because I went with Tim to pick up the parts to make these fuel lines back at his shop. We got the appropriate hoses, clamps, and fasteners and Tim put them together while I watched and learned. We waited a little bit for my engine to cool down and then they removed my old fuel lines and installed the new ones. They look pretty good. They just warned me to watch for any leaks since they were brand new and may require tightening in the first day or two as they seat in. This was no problem so with the lines installed I got into my car and started it so they could check for any leaks before I left. There was a short pause that felt like forever until John yelled 'SHUT THE CAR OFF!' I turned the key and jumped from the car expecting to see my engine up in a fuel fire, but John and Tim were laughing hysterically because I'd been fooled pretty badly. I'll never forget that one...
Driving impressions of my car with the chip were good. I felt the biggest difference at 3k RPM's where the engine was much more responsive. I attribute this to hotter spark timing in the low and mid RPM range. Assuming that I always use premium pump gas this shouldn't cause any reliability problems with the engine. I could also feel more power above 5k RPM's which I'd associate with bumping the injector cycle of the chips to deliver a little more fuel. The only drawback was that my check engine light remained illuminated at all times. I guess the chip was written with BMW software instead of the Porsche one so the computer didn't approve of it and lit the check engine bulb.
Suffice it to say, 7 horsepower doesn't satisfy the bum dyno for very long. You're always craving more performance so I did more research. I had met another 968 owner the previous summer just driving around town when I could tell his exhaust definitely wasn't stock. I followed him onto the freeway and we took an exit to meet each other and talk about our cars. This 968 had a full custom exhaust system, m030 sport suspension, bigger brakes, and some modifications to the engine. This is how I learned of David Chen and I did the muffler on my car with David's help. I looked to this guy's 968 again as inspiration for what I could do with my car. Again I called David Chen and we discussed engine performance for the 968. He would NOT let me down!
David's first suggestion was replacing the camshafts which quite frankly surprised me. The 968 uses variable valve timing to adjust the phase of the intake camshaft, depending on throttle position and engine load, from 1500 to 5500 RPM's. The result is greater midrange torque and a remarkably flat torque curve everywhere in the engine's range EXCEPT over 5500 RPM's. This is where the 968 engine runs out of steam and David knows this. His suggestion was removing the 968 Variocam completely and installing a set of 944 S2 camshafts. His reasoning was the 968 camshafts simply used too much valve overlap for an engine that only revs to 6500 RPM's. Valve overlap [in case you're unfamiliar] is where the intake and exhaust valves are open simultaneously for dynamic breathing purposes at very high engine speeds.
David's reasoning was that the Porsche factory used camshafts with this much valve overlap to burn more cleanly and meet lower emissions requirements in the early 90's when the 968 was introduced. With the early variable valve technology of the time it meant that with the torque timing shut off at 5500 RPM's the high speed engine performance would suffer due to cam specs that were developed to improve low-speed exhaust emissions. The variable valve tensioner would be replaced with another spring tensioned unit instead of the hydraulic adjuster used on the 968. This would also be more reliable with only one side of the tensioner required to tension instead of both sides like the 968 unit.
Back at Speedforce I recalled a 944 S2 engine that they had laying in the shop...John mentioned that the block was being used for a 3 liter car but spoke nothing of the camshafts. I called John to inquire about the cams and he said I could have them for a fair price. I thought about it for a week or so before pulling the trigger and when I called back got in touch with Tim. Tim wanted to sell them fast so he gave me a great deal on the cams shipped to my door. Unfortunately I opened the package to find 1-1/2 cam teeth broken off from the cams because they were packed in a couple sheets of newspaper. I got on the phone with Tim and we arranged a claim with UPS to pay for the cams being repaired. UPS covered the full cost of the cams [including shipping 3 ways] and Tim repaired them for free. When he sent them back they were packed very well and the repair was beautifully done!
Now I just needed the tensioner and some gaskets for the valve cover that would be removed to replace the camshafts. I ordered all 13 grommets, 4 spark plug hole seals, and the main valve cover seal from my local Porsche dealer. It wasn't long after that I heard from Tim Richards at Speedforce Racing. While at his shop getting the custom chips programmed for my 968 I had seen the first of their supercharged 944's. It was a very clean setup using a centrifugal blower, custom intake piping, a pulley sized to deliver 6 psi of boost at 6k RPM's and a custom chip. They had recently installed a 944 Turbo intercooler in the factory location and reworked the intake piping to accept it. They also got a different pulley increasing boost to 8 psi. After seeing my 968 at the shop Tim had come up with the idea of supercharging a 968. He wanted my car to test this supercharger kit and he would need a deposit soon in order to start. I was torn between which performance path to take!
I thought long and hard for a week or so about whether or not I wanted my 968 supercharged. How difficult could it possibly be? Tim has been fabricating for years [his work shows it, especially his welding ability] and he's familiar with Porsches so it would be a good opportunity to help develop a performance package for the car and more importantly GET MORE POWER! I spoke to Tim many times in the following weeks getting every bit of information I could before taking the plunge...I wanted to do it, I really did! But there was one thing holding me back, and if you've ever been a college student you know what it is. I was strapped for cash and couldn't drop a couple thousand bucks into the supercharger project.
Anyone whose successful will tell you that you never get what you want by budgeting your entire life away and living from paycheck to paycheck. If you want something badly you have to set a goal and work for it...so I did. Porsches don't come for free and the money to maintain them and upgrade ANY car doesn't come free either [unless of course your parents are rolling and they're generous enough to share]. So I doubled my hours at work and started saving...but Tim was enthusiastic and wanted to do get started ASAP. I understood his position because the earlier you get a product on the market, especially one that's in demand, the more likely you are to beat your competitors in the business and get your name out there.
Eventually reality set in and I had to confess I wouldn't be able to do the conversion...it was just too much money for me to spend at the time. I was bummed for a while but something pretty exciting happened. A buddy of mine who also had a 968 got in touch with Tim and they decided to do the supercharger project together. I thought this was great because both of them are good guys and I couldn't wait to see a 968 supercharger available to buy.
A couple more weeks must've passed and the thought of supercharging my car must've slipped from my mind. School was more important and the horsepower additions could wait. I returned home one weekend to spend time with the family when my phone rang. Picked it up and didn't expect John Anderson to call me on a Sunday evening. We talked for a bit before John hit me with the question: 'How would you like it if we turbocharged your 968??' HUH!!
I thought he was joking or being melodramatic at first, so I said yeah it'd be great. I love turbos more than anything...nothing in the world is like listening to a turbo spooling to life, faster and faster until it's spinning so quickly the frequency of the whistle it makes is no longer even audible. Well maybe it is but the sound of air being consumed by the engine through the filter is one you can't put into words [trust me I'm struggling to do it right now]! At this moment you're being slammed in the back with torque and acceleration that takes your vision away because you're experiencing sensory overload!! More and more acceleration as the boost peaks out and then the wastegate opens and all hell is unleashed out the tailpipe. Take a listen next time you're at the race track watching other turbo cars fly past...it'll sound like a normal car until the turbo hits boost and the exhaust note triples in magnitude. There's nothing else like it...so uhh, yeah. Back to the story sorry I was distracted, ehm.
Anyway, John was serious. I could tell by his tone. First question out of my mouth, what's this gonna cost? Not much man - was his answer. 'Not much' is relative, I wanted a dollar amount. I won't disclose that here but let's just say that I asked him to repeat that over and over until I was sure that I'd heard him correctly. I asked how we would do it and he began running through details from his vast 944 Turbo experience. He'd chosen me because I knew the 968's and with his knowledge of turbos we could do this thing and have a blast developing a 968 Turbo conversion.
See it here: http://andersonmotorworksinc.com
Can you catch my car in the intro? Also see the turbo conversions page!
