Supercars are getting more complex than ever. Sophisticated turbocharged engines, electronically-controlled torque vectoring systems and enormously clever traction control systems are now the order of the day, but it doesn’t need to be this way.
Ultima, for instance, will sell you an ‘RS’ kit car (pre-built, if you’d like) with up to 1200bhp, a manual gearbox, and a complete absence of driver aids. The British company is the first that’ll come to mind for many when it comes to supercar self-builds, but there is another worth a closer look - Factory Five.
Formed in 1995, Factory Five made a name for itself via its Shelby Cobra replica kit. It was based around a simple yet genius idea - the US firm sold you a basic kit, and then you found a later third-generation V8 Ford Mustang that donated its running gear to the cause. All being well, you had a Cobra homage for around $20,000.
A similar ethos has been used for numerous Lotus Seven-like kit cars, using vehicles including the Ford Sierra, E36 BMW M3 and Mazda MX-5 as donors. Factory Five’s take on the genre was a smash hit, with thousands of the ‘65’ Cobra kits shifted in the years following its introduction. A follow up was in order, and a more original one at that.
What Factory Five came up with was the GTM. It used a freshly-designed composite body rather than a replica shell, although the car was said to be influenced by the Saleen S7. As with the 65, this was underpinned by a tubular space frame chassis.
Rather than swap in Mustang bits, builders were required to track down a C5 Chevrolet Corvette donor. The V8 engine, suspension and more would be carried over from the ‘Vette, with Porsche’s legendary G50 transaxle - used by the 964 and 993-generation 911s - on transmission duties.
According to Car & Driver’s mostly complimentary review of a GTM back in 2007, it was possible to build one at the time for a mere $40,000. Thanks to inflation that figure will be higher today (Factory Five currently sells the kit on its own for $24,995), but you can get a completed car for not much more than that.
A GM LS6-powered example sold on Bring a Trailer a few months ago for $53,000, only a little more than the starting price of the new Ford Mustang Mach 1. That’s an incredible amount of performance for the money - we’re talking about 400bhp in a car weighing around a tonne. Some people chuck LS7s in these, making for ~3sec 0-60mph times.
The GTM seen here is powered by an L98 Gen IV crate with the power output listed on the Barrett Jackson auction page as having ‘505hp’, a figure which we’re unsure about - it’d need some hefty modifications to hit that figure. We’ve emailed the auction house which is currently double-checking, but we do know that L98s are good for around 370bhp stock - plenty in a car as light as the GTM.
Like the aforementioned LS6 GTM, this 2012 example has been seldom used, with a mere 625 miles on the clock. It’ll go under the hammer at Barret Jackson’s Las Vegas sale from 17-19 June, which also features a Toyota Supra used in The Fast and the Furious.