Cayman 4.0 Turbo

A track junkie seeks more power

November 15, 2013
Cayman 4.0 Turbo 1
Cayman 4.0 Turbo 2
Cayman 4.0 Turbo 3
Cayman 4.0 Turbo 4
Cayman 4.0 Turbo 5
Cayman 4.0 Turbo 6
Cayman 4.0 Turbo 7
Cayman 4.0 Turbo 8

It was a recurring nightmare for Bruce Blockus, a bleak scenario that played itself out on track days up and down the East Coast. It always started with a corner—it could be a fast or a slow one—and the rear bumper of a 911 close enough for him to read the serial numbers on the license plate’s expiration sticker.

Being held up in the corners wasn’t just killing his lap times. The most frustrating part was watching the 911s pull away down the straights, only to be reeled in once again in the next corner. Blockus was trapped in racer’s purgatory.

As a PCA driving instructor and track junkie, Blockus would end up clocking plenty of hard-earned miles on his 2007 Cayman S—until rod bearing number six failed at 25,000 miles. He considered both a rebuild and an engine swap, but he was determined to put an end to the torture of watching those 911s block his way to the front.

Blockus had thought about upgrading to a 3.8-liter Carrera S engine with the X51 power package, which he’d then optimize with aftermarket headers and a freer flowing exhaust system. He weighed that against TPC Racing’s Cayman S turbo kit, which had been on the market for about 18 months and had received good reviews from participants in the Cayman forums. In the end he opted for TPC’s kit: It offered more torque and cost about the same as the 3.8 swap.

The car was then shipped to TPC in Maryland, where company technicians installed a factory remanufactured 3.4-liter with TPC’s Stage 2 single-turbo kit, which, according to TPC, is good for 460 hp at 7200 rpm and 402 lb-ft of torque between 4000-4800 rpm.

Blockus thought highly of the TPC system, saying the extra torque and lag-free response gave it great driveability around town and, more importantly, he could finally outrun the 911s that previously had toyed with him. Then, another catastrophe: Rod bearing number six failed on his second engine as well—coincidentally, again at 25,000 miles.

Blockus said there are two prevailing theories regarding the rod bearing failures. One suggests the 3.4-liter’s heavier pistons, when compared to the standard Cayman’s 2.7-liter’s pistons, were too much for the stock engine’s rods and rod bolts, causing the big end of the rod to deform, opening up bearing clearance and eventual failure. The second theory suggests the engine needs additional scavenge pumps in the heads to send the oil back to the sumps under high cornering loads. Blockus believes the first theory is the more plausible of the two, as he’s seen 2.7-liter Boxsters and Caymans log plenty of miles on the track and are still running strong after 100,000 miles.

Also from Issue 215

  • David Donohue track tests the Turbo
  • A missing link in the 911's life story
  • Who should get credit for the design?
  • 987/997 ignition events and your warranty
  • Porsches and guitars--a great mix
  • Restoration as a labor of love
  • 1975 Carrera finds a new venue
  • A historian's look at the 356's birth
  • RS enthusiasts gather at Rheims
  • Could this car be worth $500,000?
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