{"id":2127301,"date":"2026-09-04T00:00:00","date_gmt":"2026-09-03T21:00:00","guid":{"rendered":"https:\/\/analyse.optim.biz\/?p=2127301"},"modified":"2026-09-04T00:00:00","modified_gmt":"2026-09-03T21:00:00","slug":"just-a-bloke-in-a-shed-this-man-built-an-800bhp-f1-inspired-hypercar-in-his-garage","status":"publish","type":"post","link":"https:\/\/analyse.optim.biz\/?p=2127301","title":{"rendered":"“Just a bloke in a shed”: this man built an 800bhp F1-inspired hypercar… in his garage"},"content":{"rendered":"
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I point to a graffiti-covered bus stop in a layby, signalling to stop for a quick photo. That\u2019s the excuse, anyway. In truth, I need a moment to stand on solid ground. After riding shotgun with Jeff, my head feels like I\u2019ve just been bench pressing 160kg with my neck. Then again, 1.2g under acceleration will do that.<\/p>\n

The numbers behind the Quantum GP700 are impressive: 800bhp, 748kg (wet), 0\u2013100mph in 4.4 seconds. Top speed remains untested, though it\u2019s geared for 193mph. Fastestlaps.com shows a 1:25.60 lap time around Winton National Circuit \u2013 nearly four seconds faster than a Merc-AMG GT R Pro.<\/p>\n<\/div>\n

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I meet Jeff David at his Gisborne property in the Australian state of Victoria to figure out how something this extreme could emerge from a backyard workshop without commercial backing. Jeff insists he\u2019s \u201cjust a bloke in a shed\u201d, but most blokes aren\u2019t using a digger to simulate downforce on their homemade, F1-inspired hypercar.<\/p>\n

Words and photography: Toby Thyer<\/em><\/p>\n<\/div>\n

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Jeff\u2019s story starts with bikes. He spent years as a KTM team rider and has a wall of trophies to prove it. So why not stick with motorcycles? \u201cI was getting too old for dirt bikes and fast road bikes are just too dangerous,\u201d he says.<\/p>\n

\u201cThe only place you can use that kind of speed safely is on a circuit. I wanted something like an Atom after seeing Clarkson on Top Gear. It just made sense. Fast, but usable.\u201d<\/p>\n<\/div>\n

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He imported an Ariel Atom in 2005, but even after the painful process of getting it road legalised, it proved unsatisfactory on public roads. Jeff started pulling it to pieces and reworking every single part. At one point, he even sent pushrods to a mate at McLaren for fitting strain gauges. It turned out that when all 400bhp was unleashed, only 15kg was being carried by each front wheel. That\u2019s not a great recipe for handling.<\/p>\n<\/p>\n<\/div>\n

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Armed with data from MoTeC systems and simulation tools like Bosch\u2019s motorsport suspension software, Jeff made a bold decision. He cut into the Atom\u2019s chassis and extended the frame by 12cm. \u201cIt instantly improved handling,\u201d he says, \u201cbut it was never going to be a 2g car as it lacked aero. I decided to build my own, using what I had learned and starting with a blank sheet of paper. But its concepts were based on F1 and F2 of that era.\u201d<\/p>\n

Jeff\u2019s background in dirt bikes became the foundation for the GP700. \u201cI tuned suspension for bikes that won their class at Finke,\u201d he explains, referring to Australia\u2019s brutal desert endurance race. \u201cEventually I was tuning bikes regularly on my dyno.\u201d That hands on approach evolved into a deep understanding of everything from combustion chamber design to suspension witchcraft.<\/p>\n

\u201cCompared to bike suspension, road car suspension is prehistoric,\u201d he says. \u201cThe systems I use date back to 1998.\u201d Jeff logged suspension data from one of his best performing bikes, translated it into spreadsheets, and built a kinematic model in a 3D CAD software called SolidWorks. \u201cThat let me apply 40 years of bike suspension development directly to the car.\u201d<\/p>\n

The engine is an imaginative mongrel based on Honda\u2019s K-series \u2013 a CR-V block teamed with a Type R head and an S2000 F22C crank. But beyond the base castings, everything is custom. Sleeves, rods, pistons, cams, porting, manifolds \u2013 the lot.<\/p>\n

\u201cAbout 30 per cent of my effort has gone into developing the K-series,\u201d Jeff says, lovingly describing his bespoke internals. \u201cPiston crowns were shaped by hand, porting optimised and tested on the dyno until I got the results I wanted. They eventually became off the shelf products \u2013 without asking me,\u201d he adds. He also sent a hand ported cylinder head to 4Piston Racing, who sent back two CNC ported heads in return.<\/p>\n

The gearbox is equally bespoke, a six speed, air-shifted Holinger unit. \u201cThey used CAD data from my rear chassis to design a custom gearbox,\u201d Jeff explains. \u201cI couldn\u2019t afford the rights, so they kept it \u2013 and it ended up as OEM equipment on the KTM X-Bow.\u201d It\u2019s coping with two times its rated torque.<\/p>\n<\/div>\n

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\"Wheel<\/p>\n<\/div>\n

When he committed to building a new chassis from scratch, weight and strength were the priorities. It also needed to meet Victoria\u2019s strict road registration standards. To accelerate development, Jeff enlisted 11 university students completing their final year theses. \u201cI was the industry supervisor and had three students focused on the chassis \u2013 CAD, torsional rigidity, all of it,\u201d he says.<\/p>\n

Testing was all done in his shed. \u201cI bolted the rear of the chassis to the concrete slab, attached a pipe to the middle, hung a cement bag off it \u2013 because I\u2019m old school, and measured deflection with a steel ruler,\u201d he laughs.<\/p>\n

\u201cBetween that and the CAD work, we nailed it.\u201d Insights from cracking aluminium dirt bike frames informed the design, resulting in a lightweight yet immensely strong structure. The rear cross member, cut with a high pressure water jet, weighs just 2.5kg but can handle 800bhp.<\/p>\n

Alignment was also carefully considered \u2013 \u201cI didn\u2019t want it to be difficult to build straight,\u201d Jeff says. \u201cThe nose section dovetails together, so as long as the jig is accurate, suspension alignment is accurate to within half a millimeter.\u201d The bodywork keeps a hands on approach. \u201cI knew it needed a Formula One-style front wing and nose,\u201d he says.<\/p>\n

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\"Wheel<\/p>\n<\/div>\n

The design went from Jeff\u2019s imagination into Maya [3D modelling software], and with help from his son Andrew, he refined the surfaces. Foam blocks were CNC routed, layered with raw carbon fibre, and finished by a body shop. \u201cI\u2019ve still got the moulds upstairs.\u201d<\/p>\n

Electronics tie everything together \u2013 before all this, Jeff worked as an electrical engineer for Honeywell, a kind of Winston Wolfe for critical systems across industries from oil rigs to airports, and it\u2019s clear he\u2019s well versed in speaking technically. \u201cSome calculations happen in Emtron, some in MoTeC, and they share data, much like a computer network,\u201d he explains. Righto. \u201cMany sensors are off the shelf, but the data analysis has been customised over decades of refinement.\u201d Yes. Good. And it\u2019s painted red<\/em> you say?<\/p>\n

The big question then: where can we buy one? \u201cI had potential investors,\u201d Jeff says, \u201cbut it all fell through. It would cost too much to build them here.\u201d It\u2019s a bittersweet conclusion. The Quantum GP700 is a masterpiece of engineering, born from decades of experience, ingenuity, and persistence \u2013 all inside a shed by a bloke with a vision as wide as Australia itself.<\/p>\n

If this is where the story ends, it feels like a loss. But for now, the GP700 exists as proof of what one bloke in a shed can achieve with passion, know-how and a very patient wife.<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

I point to a graffiti-covered bus stop in a layby, signalling to stop for a quick photo. That\u2019s the excuse, anyway. In truth, I need a moment to stand on solid ground. After riding shotgun with Jeff, my head feels like I\u2019ve just been bench pressing 160kg with my neck. Then again, 1.2g under acceleration […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[226,237],"class_list":["post-2127301","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-crawlmanager","tag-topgear-com"],"_links":{"self":[{"href":"https:\/\/analyse.optim.biz\/index.php?rest_route=\/wp\/v2\/posts\/2127301","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/analyse.optim.biz\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/analyse.optim.biz\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/analyse.optim.biz\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/analyse.optim.biz\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2127301"}],"version-history":[{"count":0,"href":"https:\/\/analyse.optim.biz\/index.php?rest_route=\/wp\/v2\/posts\/2127301\/revisions"}],"wp:attachment":[{"href":"https:\/\/analyse.optim.biz\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2127301"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/analyse.optim.biz\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2127301"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/analyse.optim.biz\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2127301"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}