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With Vision Motorsports, we built a 2007 987.1 Cayman S race car over 10+ years, developing the chassis from an AX car, to time trial, to street stock club racing, to GT class leader. The most recent configuration was a 4.2L M97 engine with a short ratio G87.21 six speed manual. While the car was quite successful, winning 5 POC GT3 class championships and setting multiple track records, long-term reliability of the M97 derived engine was limiting further chassis development. And the introduction of the PDK GT4 Clubsport was threatening our competitiveness on tracks with multiple full-power up shifts (data indicates approximately 0.1 - 0.15 seconds per shift). Photo below:
Plan:
Update the 2007 987.1 to a 2011 987.2 DFI/PDK and increase power by swapping the stock 3.4L DFI engine for a 3.9L 9A1 race prepped DFI engine (bored from a long stroke 3.6L Carrera engine)
Execution:
We sourced a running 2011 Cayman S PDK with Sport Chrono and factory LSD (which had already been updated with a Guard LSD) to serve as a donor for the engine core, PDK, chassis and engine harnesses, ABS pump, fuel pumps, all computers (engine, PDK, climate control, etc), dash, shifter, etc. We estimate that this was the most cost effective way to obtain all required parts that were known to work reliably together.
Vision Motorsports techs stripped the race car and donor and began to transfer all required parts while the engine builders modified the Carrera-based 3.9L DFI engine to work in the Cayman, including transferring all ancillary parts and improving/updating other parts as needed (oil cooler, intake plenum, etc.). The engine and transmission were then mated and test fit into the chassis and ensure that everything clears the diffuser (not shown).
The team then identified anything that needed to be modified to work in the legacy chassis. While most parts were direct bolt on, we did need to source new headers (M&M 987.2 race headers), fabricate new exhaust, fabricate new rear ARB and mounts to compensate from the previously modified rear sub-frame, rework the prior engine oil cooler to serve as the PDK gearbox cooler, install a larger PDK ATF cooler, install the 987.2 bumper and taillights (and headlights), and re-work the AiM and radio systems. We also decided to use the GT4 Clubsport factory steering with with integrated paddles as it is plug and play with the 987.2 wiring system.
All work was completed over a two to three month period by a single, experienced Vision Motorsports tech (with occasional support from other techs).
Results:
The car is nearly complete and is currently testing on the dyno (tune refinement). Early results are excellent and all systems appear to be working together properly. Our first on-track test is this coming weekend at Willow Springs. Following what we expect to be a successful test we will update the PDK software and make a few additional changes (headlights, cooling ducts, etc.).
Can I ask what drove you towards selecting such a major upgrade path instead of selling your car then purchasing and updating a Clubsport?
Primarily cost. This solution is much less expensive, given that I could sell the M97 engine, short ratio gearbox, Teves ABS, donor chassis, etc. to recover most/all of the cost of the donor and some of the labor.
Also,I believe, that the ultimate performance will be better on a majority of tracks that we run. Our chassis is very well sorted with good aero, wider tires, excellent geometry, etc. Additionally, I just wanted to do it as I like to tinker. Not real thrilled with the aluminum chassis on the CS.
Finally, this way most the money I spend goes to pay the wages of shop techs that I like and consider friends, and not to someone I don’t know to purchase the CS.
Primarily cost. This solution is much less expensive, given that I could sell the M97 engine, short ratio gearbox, Teves ABS, donor chassis, etc. to recover most/all of the cost of the donor and some of the labor.
Also,I believe, that the ultimate performance will be better on a majority of tracks that we run. Our chassis is very well sorted with good aero, wider tires, excellent geometry, etc. Additionally, I just wanted to do it as I like to tinker. Not real thrilled with the aluminum chassis on the CS.
Finally, this way most the money I spend goes to pay the wages of shop techs that I like and consider friends, and not to someone I don’t know to purchase the CS.
Cheers,
Thanks for explaining - makes good sense. This type of work is where new ground can be broken in developing a platform. Best of luck with the car!
Primarily cost. This solution is much less expensive, given that I could sell the M97 engine, short ratio gearbox, Teves ABS, donor chassis, etc. to recover most/all of the cost of the donor and some of the labor.
Also,I believe, that the ultimate performance will be better on a majority of tracks that we run. Our chassis is very well sorted with good aero, wider tires, excellent geometry, etc. Additionally, I just wanted to do it as I like to tinker. Not real thrilled with the aluminum chassis on the CS.
Finally, this way most the money I spend goes to pay the wages of shop techs that I like and consider friends, and not to someone I don’t know to purchase the CS.
Cheers,
Very interesting project and a lovely reason.
Interested to hear how the test goes and car develops.
Awesome. Cool to see proper GT car development in an era of spec racers. Seems like there isn't much Vision can't do in their workshop. Good luck with the testing!
01-06-2019, 07:33 PM
2007 987.1 Race Car Update to 987.2 DFI/PDK
