David Brown’s twin-turbocharged Lotus Carlton tourer is a one-off custom build following many years he’s spent playing with Vauxhall’s 377bhp super saloon…
David Brown’s unique Lotus Carlton tourer.
Visitors to the last Vauxhall Bedford Opel Association (VBOA) National Rally to be held at Billing Aquadrome will remember the gorgeous Imperial Green Carlton estate driven to the event by serial Griffin modifier, David Brown. Fresh from its long journey all the way from the electrician’s home near Edinburgh, the custom cargo carrier was wearing a modified Lotus Carlton body kit, the legendary model’s wheels and the bulk of its interior. The wicked wagon was finished to such a high standard it would have convinced those less familiar with Vauxhall’s output they were looking at a genuine Lotus Carlton tourer until David opened the bonnet to reveal a naturally aspirated three-litre inline-six.
“The car was originally a red two- litre Diamond estate on a K-plate. I bought it in as a non-runner fully intending to turn it into the Lotus Carlton tourer Vauxhall never made. I’d played about with Carlton estates in the past, fitting a genuine Lotus body kit to a blue three-litre Diamond estate, but in truth, that was little more than a styling exercise. The project based on the red car was intended to be a challenge to myself, one which would test everything I’ve learned from owning Carltons over the years,” he says.
David has owned four genuine Lotus Carltons to date. He bought his first Type 104 (the official Lotus designation for the model) back in 2001. From that point onwards, he had the good sense to stockpile every genuine Lotus Carlton spare he could lay his hands on, from badges to bumpers, wheels to window rubbers. Contrary to the lofty prices
these cars fetch today, they weren’t worth a huge amount of money back then, which means he built up an impressive collection of parts without breaking the bank.
“I’ve never understood why Vauxhall didn’t put a Lotus Carlton tourer into production,” he admits. In today’s world of estate cars being dressed in aggressive body kits and being powered by engines producing big bhp (hello to all you Audi RS6 owners), the idea of a twinturbocharged load lugger doesn’t seem particularly unusual. Moreover, it’s difficult to argue against the case for a Type 104 tourer when the car David has created looks so good. Don’t be fooled into thinking this Imperial Green giant’s Lotus DNA is only skin deep, though.
matter of time
He always had his heart set on fitting the Lotus Carlton’s 377bhp twinturbocharged C36GET inline-six and its accompanying ZF six-speed manual gearbox (the same cog cruncher fitted to the Corvette ZR-1, accompanied by a Holden Commodore V8 limited-slip differential when used in the hardhitting Vauxhall), but with sale prices rocketing skyward and a drought when it comes to finding owners prepared to part with
their spare engines, he decided a naturally aspirated Carlton GSi3000 24-valve three-litre powerplant would enable him to get some use out of the car after the many hours spent fitting Lotus leather, bodywork and a sea of chassis components.
“I wanted to use a leatherequipped Diamond as the platform for the project so I could retain the original rear bench, which is a close match for the Lotus Carlton’s front seats,” continues David. Indeed, the super-sumptuous Diamond leather looks great against the Connolly hide up front. “Other than the body shell and the retained back seats, there really isn’t very much Diamond left!” he laughs.
He’s not fibbing. Virtually every part which could be replaced by uprated Lotus Carlton componentry has been ditched. Dampers, coil
“other than the BodY shell and BacK seats, there reallY isn’t much diamond left!”
springs, brakes, differential, alloys. Even the exhaust and catalytic converters are Lotus Carlton parts! Padded dash trim, the steering wheel, sill covers, subframes. No matter the Type 104 component you care to name, the likelihood is David has squeezed it into place.
miX and match
“All Carltons share the same underpinnings,” he remarks. “There are differences between the subframes of 12-valve and 24-valve models due to changes in engine mounts, but other than having to take this trait into account, swapping mechanical equipment between Carltons is a fairly straightforward process,” he says, acknowledging he’d laid the groundwork for the C36GET swap by fitting the three-litre engine. Now all he needed to do was identify a willing donor!
He struck lucky when a complete Lotus Carlton engine, gearbox and subframe package eventually presented itself as available for purchase. Delivered to his Scottish residence on a pallet, the parts were promptly separated before the engine was sent away for a complete rebuild, including the fitting of uprated timing chains. Vauxhall and Opel modifying specialist, A&M Conversions in Deeside, was asked to manage the overhaul of the twin Garrett T25 turbochargers, which were seized due to being out of action for so long.
“A&M boss, Antonio Lommano, returned the turbos as hybrid units complete with 360° thrust
bearings, offering improved performance over standard specification,” confirms David. A&M’s work didn’t end there, though. “After the rebuilt engine was fitted, Antonio spent a significant amount of time sorting the ignition, fuelling and throttle action. He also modified the sump to improve the turbocharger oil return feed. The inlet was machined, high-impedance injectors were fitted and after much fine tuning, the 3.6-litre Lotus lump was finally up and running.”
Among other jobs, Antonio was also called upon to sort unidentified wiring and electrical gremlins, fit a heavy duty clutch and offer David advice whenever he found himself stumped while working on the car north of the border. “The biggest challenge was the physical distance between us,” reasons the proud Scot. “I spent a lot of time driving backwards and forwards to Deeside with the car on a trailer! Of course, doing so was completely worthwhile, and it goes without saying I’m thrilled with the assistance and reassurance Antonio has provided me with throughout the build,” he stresses. There was also the nail-biting first turn of the key to concern himself with. “I was worried the Type 104 Motronic ECU I’d sourced wouldn’t fire up after being out of action for years. It’s a very difficult part to find and replace. I was a wreck in the lead up to the car springing into life. I felt as though I was nervously awaiting the birth of a baby!”
Producing a conservative 330bhp and 330lb/ft torque at 85% throttle, this devastatingly cool Diamond shifts rapidly, but David is aware he needs to exercise restraint during the first five hundred miles of ‘bedding in’. The car will return to A&M for further fettling thereafter. “I’m going to commission GAZ to make an application-specific set of dampers for my car,” he says, pointing out the continued use of Diamond estate rear shocks, albeit with Lotus Carlton springs in place. He’s also talking to the DVLA about officially registering the car as a Lotus Carlton Tourer. And as if that wasn’t enough to keep him busy, he’s started to map out his next Carlton-based build. “I want to assemble another Lotus-looker, but this time I’m keen on the idea of powering it with a three-litre inlinesix, a single Garrett GT35 turbocharger and DTA standalone engine management. Antonio will be involved with the build. I can’t wait for the two of us to get stuck in!”
Producing what he sees as a missing piece of Vauxhall’s back catalogue, David has combined power, style and practicality in a pristine performance package. With ongoing help from A&M Conversions, we have no doubt this twinturbocharged tourer will continue to go from strength to strength. Look out for it at forthcoming Griffinthemed shows. Believe us when we say you won’t be disappointed!
“antonio spent a significant amount of time sorting the ignition, fuelling and throttle action”
Twin Lotus Carlton head units are waiting in the wings Every Lotus Carlton part which can be fitted to the estate has been fitted to the estate! A satisfying sight for any driver Irmscher Omega B tailgate spoiler is a good match to Lotus Carlton body trim
a&m conversions provided twin Garrett T25 hybrid turbochargers
David’s car looks every bit a factory Lotus Carlton cargo carrier