Vision Motorsport
Estimated time:
16 hours
Upgrade parts:
$3,500 (turbo system)
$500 (Link eng mgmt)

I purchased this 944 Turbo because I loved the looks, price, and performance. It didn't hurt that I've always loved Porsches anyway. But, I also bought the 951 because it was already turbocharged, making it much easier to get substantial horsepower gains from bolt-on upgrades.

Rather than take small steps to gain power with a more efficient intake and reprogrammed software, I decided to start from a higher performance plateau and swap out the turbocharger for a larger unit. I know...I wrote in Part 1 (ec, 11/03) that the goal was 300 whp, which is not too hard to accomplish with the stock turbo. However, anyone who knows me, and those who followed along on my Project BMW M3, realizes I'm power crazy. Actually, I wanted to get past that 300 mark with a slightly larger turbo, not so much for raw power but so intake temps are kept under better control and turbo efficiency remains at a maximum. Enter Kokeln Racing Products.

Kokeln's Stage 5 turbo upgrade is comprised of several components, including an intake, dual-port wastegate, new intercooler piping, bigger injectors, a fuel-pressure regulator, Kokeln custom-programmed chips and, of course, the Stage 5 turbocharger. The new blower has a much larger compressor and exhaust side, which, according to Kokeln, and in testing has shown over 400 whp. A question to be answered is whether this setup allows more "lag" compared to the stock unit. Kokeln stated it had tested 10 stages of turbos during development, and the data shows this system is best.

"Stage 5 worked best in a high-performance, stock environment. By stock environment, I mean stock manifolds and size and location of the intercooler," said Kokeln founder Dwain Dement.

Kokeln also offers a couple of options with the Stage 5 system. For quicker spool-up, there's a ball-bearing turbo, and a Link Engine Management system overrides the ECU and completely controls fuel mapping for a truly custom setup. Required for this system to work are a different air intake boot to the turbo, new air-temp sensor and a different location for the air cleaner. For Project 951, I didn't go with the ball-bearing option, but I did end up with the Link system, and I was extremely excited about having it dialed in.

The Link system is being sold exclusively as a turn-key product for 944 Turbo owners. Currently, Kokeln sells the Link with a base map for stock as well as the big Stage 5 turbo upgrade, but the company plans to rewrite the Link instructions to make them easier to follow.

The engine management system will also allow the end user to load up the base maps and from there custom tune the car as desired, be it for more power, a race gas setup or even for better gas mileage. Even if you completely screw up the programming and accidentally save it, there's a default option that will take you back to the base 944 maps originally programmed by Kokeln. If you desire to tune your own car, the best way to do it is on the dyno.

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