Greetings,
I've come here as a new member to share some of my work to other 928 enthusiasts out there. My project was to take a garden variety 928 S4 and add the best form of forced induction, namely turbocharging. To further this, the system had to be top notch in its method of approach, both from a technical and aesthetic standpoint.
The 928S4 twin turbo system offers the following:
2 Garrett GT series liquid cooled ball bearing turbochargers 750+ HP capacity
2 Air to Air bar and plate front mount intercoolers 10"X4.5"X8"
High energy pulse flow designed exhuast manifolds, ceramic coated
Dual Bosch compressor bypass valves
Split exit downpipes, seperating wastegate exhaust flow from turbine discharge, ceramic coated
Dual air filtration and inlet snout system
Proprietary MAF junction box
JDS Porsche SUPER MAF
Shark Tuner massaged EPROMS, fuel and ignition as required
Run delay turbocharger water circulation system allowing water circulation through turbochargers after engine shut down.
This, that and the other...
This has been a very argued about project for the last 3 years. I promised to bring back a full blown (no pun intended) twin turbo system for the Porsche 928S4. Why? Beacuse the car is worth such a system and this is the way Porsche would have built it. I have been working with turbocharged Porsche 928s since 1990 and it has always been a dream to build the ultimate 5.0 liter 32V 928 street machine for me. I also grew really tired of hearing that a Centrifugal Supercharger was the "top dog" way to go for the 928 and that "turbos don't work on a 928" Some people claim this is an imaginary project, or won't work, won't outperform a supercharger, is too complex, etc. Not true as the below pictures show.
I investigated the "rear mount" turbocharger system for the 928 well over two years ago. I could never draw myself to even remotely warm up to that setup because the turbocharger is designed to extract the raw heat energy from the exhaust pulse. Additionally, mounting the air cleaner(s) under the vehicle was simply unacceptable to me. That meant front mounting was the only option for me, as it is for any factory setup or top notch tuner working in this field. Furthermore, splitting the bank loading with twins is the natural layout progression for a turbocharged V8 and is Porsche and Audi's choice for nearly all of their new turbcharged vehicles. In fact, BWM has seen fit to equip the new 3 series with twin turbos. The value is in generating an extremely responsive system, one which can deliver an ultra-wide powerband, not just a peak, chest-pounding dyno number. The widest powerband per pound of boost was the ultimate goal. I expect this setup to run circles around most new high performance cars on just 5 psig.
I attach some pictures of my project. In the next 3-4 weeks I will be putting the finishing touches on the system and running the car in. The first setup will run a low 8 psig, but I'm expecting some serious performance at even these low boost levels. After all we are chasing 5 full liters of displacement here with the latest in Garrett turbocharger design.
To date, this project represents 1000+ hours of investigation, engineering, fabrication, installation, etc. My motto has always been to do it the best way possible.
For those willing to write the check I can be willing to supply the systems. More information coming by February, 2007.
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