British 911 restomod maker Theon Design has turned its attention to the 964 Targa and created a Signal Yellow stunner with 410bhp and chassis stiffness on a par with a regular hardtop.
To reach that power output of more than 100bhp per litre from its normally-aspirated 3.8-litre straight-six motor Theon has engineered new cylinder heads, cast from motorsport-quality aluminium and then CNC-machined inside and out. Revised port design improves airflow and air speed, while there are also new intake and exhaust valves, a single-mass flywheel, and an updated version of Theon’s switchable ceramic-coated exhaust system. Peak power comes at 7,700rpm with 285lbft of torque available at 6,650 revs. A six-speed manual transmission to 993 RS specification sends drive to the rear wheels.
To cope with the significant hike in performance Theon has developed an ingenious motorsport-derived bracing system formed from two carbon fibre tubs which fit the floor of the Targa chassis. Created from a sandwich of toughened epoxy pre-preg carbon fibre and aerospace-grade Nomex honeycomb these tubs are bonded to the existing chassis and bulkheads. Theon reckons this system makes the roofless Targa just as rigid as its Coupe restomods.
“Our latest Targa commission, GBR005, takes the open-top, air-cooled Porsche driving experience to a new level,” says Theon Founder Adrian Hawley. “Thanks to our innovative bonded carbon tub system, there are none of the dynamic drawbacks that you typically get with a convertible. We’ve been able to achieve the rigidity and handling precision of a coupe, with the added sensory rush of an open top car.”
Giving it similar levels of handling prowess are a set of switchable five-stage electronic dampers from Tractive, with brakes from a 993 RS and 17-inch Fuchs wheels.
The chassis is clothed in a full carbon body which, along with a variety of other weight-saving measures such as an aerospace-spec wiring loom, makes Theon’s Targa some 300kg lighter than the original donor vehicle.
The cabin isn’t that of a stripped-back racer, however, with touring style front seats, with classic tartan trim and even rear buckets modelled on those in the 928. There’s plenty of carbon to save a few pounds, but you’ll still find luxurious leather, air conditioning and a neat integrated phone mounting system and a high-end Focal audio system.
As a final touch the Targa roof panel has been rebuilt to modern tolerances, trimmed in mohair and comes with a bespoke bag so it can be left at home or stored away in the frunk.
Pricing starts at £430,000 plus taxes and shipping, with a build time of 18 months.
