Paul Colbran achieved his long-term ambition of building a roof-chopped Clubman, and the final creation features a 2.0-litre turbo engine from a Vauxhall Astra VXR!
Paul Colbran’s roof-chopped and Vauxhall-powered Clubman has to be seen to be believed.
Adrenaline rushes are easily achieved in a Mini; simply attempt a daring singlecarriage way overtake with a truck coming in the opposite direction and wheezy 850 under your bonnet. Alternatively, find a ridiculous engine to shoe-horn up front and see how that pans out. Paul Colbran has a history of bolting large engines into small cars, some more successfully than others. And with its 5.5-inch roof chop, his latest creation has to be
the smallest and most eye-catching yet. Once the initial confusion subsides, passersby soon notice that the original A-Series has been replaced with something a whole lot more sinister.
The project started around 15 years ago after Paul sold his home-built Vauxhall Astra with a 6.0-litre Chevy small block driving the rear wheels. Actually, there were two projects in the pipeline at that stage - this Clubman and a V8-powered Minivan. Eventually though, he realised one custom Mini project would give more than enough scope to build something radical. He’d always fancied trying to roof-chop a Clubman, while a Vauxhall XE conversion looked fun. So it began...
To avoid excess bodywork, it was still important to find a solid car to begin the transformation, regardless of the custom plans. “The whole reason I went for this one was the floors,” says Paul. “It was full of water inside, so that was a pretty good sign, as it wouldn’t have filled up if the floor had been rotten.” Ah, good point.
Sure, there was still some rust in the shell, but nothing deemed too difficult to repair at home. The front end was in need of repair, the outer sills a bit crusty, while a crease in the boot floor hinted at a previous accident. Otherwise, for an old Mini Clubman, it was in surprisingly good shape.
“I had three cars to salvage parts from initially - the Mini, a Vauxhall Calibra and a Metro GTi,” Paul continues. “The Calibra had a 2.0-litre 16-valve XE motor, while I’d read that the Metro front subframe and suspension could be needed.” A second, early-generation XE engine also joined the party, as it included a distributor for the ignition to keep things simpler. The Vauxhall injection/inlet setup is far too bulky to fit inside the Mini engine bay, so most opt for a pair of twin Weber carbs.
But before any engine conversion work could get under way, Paul braced-up the shell and prepared to trim down the roof. We’d pretend that it was all in aid of an aerodynamic improvement, but it was purely aesthetic. “I remember seeing a roof-chopped Clubman when I was young, and always fancied doing the same,” Paul explains. “It was a lot more difficult than I’d imagined though; it wasn’t as simple as cutting down the pillars and welding it back together again. In the end I had to weld together six separate sections from two different roof skins, as the roof gets wider and longer the more you lower the pillars down.” Trying to avoid warping the roof
“It wasn’t as simple as cutting down the pillars and welding it back together”
was particularly time consuming, as the metal is so thin it heats up very quickly.
Even with much time and patience the roof was still looking uneven on top, and Paul wanted to avoid big sloppy plastering with body filler, as it would only have cracked on the first speed bump. Instead he chanced upon a 1970s full-length sunroof, which would literally remove the issue. Hole cut, the outer frame went in a treat, problem solved, except the material inside was torn up and needed replacing. “Then I found an electric Webasto on eBay from an MPi,” says Paul. “It came with a section of the roof and was in better shape, so I went with that instead.”
There’s no easy way to install a Vauxhall XE engine in the front of a Mini, even a Clubman with its longer rectangular snout. For starters, the inner wings must go, with a removable front end inevitable. The bulkhead may need re-working in places for clearance, then there’s the subframe to consider.
“The Mini front subframe is too narrow for the Vauxhall engine as the gearbox sits on the side, not underneath,” Paul explains. “At the time there were pre-made subframes around that used Metro front arms, but the whole project was put together on a budget, so I decided to have a go myself. I took the towers from the Mini subframe and welded them to the lower rails of the Metro subframe to get more width.” The assembly was strengthened up significantly to take the power, then reinforced to the shell to make up for any rigidity lost with the inner wings.
The Frankenstein front subframe now consists of Metro GTi lower arms, modified Mini top arms to accept
Gaz coilovers and Metro GTi front hubs. The front wheel stud holes were also re-located and re-drilled to suit the Mini’s imperial pattern. It’s far from a simple DIY task, but proves that with enough time and effort, anything is possible at home. “I had a go at sleeving the driveshafts,” Paul continues, “to connect Vauxhall inner joints to Metro CVs, but I wasn’t convinced they’d handle the power. So I went to see Alan Stone at SLS Fabrications to have them professionally welded up.”
Another issue is the wide front track width as a result of the subframe and engine swap. It means that the front hubs are considerably wider than the standard Mini rears. So what to do? Some have used monster rear wheel spacers, or the other option is wider rear wheels with more negative offset than the fronts. An unusual set of Compomotive five-spokes was eventually sourced online, with 6x13s up front and 8x13s on the rear. Who knows what British car they were once fitted to, but they look rather good on a Mini Clubman. They were also far cheaper than a set of custom offset splitrims - the third option on the list.
Retirement, a house move, and restoration project saw Paul’s Clubman hastily bolted together then parked in storage for few years. The danger was having plenty of time to mull over the build. “The XE conversion had been done before,” he says, “and I thought, if that engine went in okay, why not try something more modern and refined.” Enter stage two of the project and much searching of online salvage auctions.
While the 150bhp Vauxhall engine was mighty fast in 1980s Astra GTEs, 30 years on and Vauxhall Astras are a whole lot heavier. More powerful too, with turbos and fuel injection now commonplace. In 2005 the BTCC-style Astra VXR was launched, with a new 2.0-litre turbo engine boasting almost 250bhp as standard. Wagon wheel alloys, a wider body kit and fast and furious centre exhaust made the new performance model a hit with boy racers and track day heroes alike. As a result, there’s a lot of crash-damage salvage ones around.
“The engine looked quite similar to the XE and I thought it would make a good conversion,” says Paul, who went in search of a donor car. “At the time I hadn’t quite realised how involved the wiring and setup would be, but I found a scrap car for about £1,200. The other engines I had needed to be rebuilt anyway, so I thought this would be comparatively cheap power.” The Astra had been tuned-up by its previous owner
“The engine looked similar to the XE and I thought it’d make a good conversion”
and came with a rolling road report showing over 300bhp. The main advantage in buying a complete car was that it came with a six-speed gearbox and all the ancillaries. The main disadvantage was that all four wheels were missing, and the seats, which made loading it up a challenge!
Back home and the conversion could begin. “Fitting the engine and ’ box was easy enough,” says Paul, “although being turbocharged made space even tighter in the engine bay. I wanted the whole lot to fit inside the bonnet, including the intercooler.” Eventually he conceded to the fact that it wouldn’t all fit.
The Astra’s radiator now lives in the boot, plumbed in through the cabin and back under the floor with an electric water pump mounted remotely. The oil filter housing and alternator also needed to be re-located to squeeze it all in. It’s a little bit unorthodox, but does maintain a smidgeon of standard Mini Clubman styling.
“Looking back, it would have been a lot easier to have stuck with the XE engine,” Paul admits. “I had the idea of transplanting over everything from the VXR, so the clocks and ECU, even the remote start key and wiring, but being a later CANBUS system it’s not that simple.” When there’s a drive-by-wire throttle pedal and wiring ‘ junctions’ for every conceivable bulb and gadget on the car, DIY swapping the electronics over to a Mini is like attempting a brain transplant on the dining room table. Retaining the Mini’s loom, then adding an aftermarket ECU to run the engine alone was the only way forward.
Paul took advice from Colin Thorndyke at Atspeed in Essex, a font of knowledge on ECU re-mapping, who advised to change the throttle setup for a Peugeot 106 GTi type, converting to a mechanical cable. Atspeed then supplied an Omex ECU and loom, which could be mapped from scratch to suit the VXR
engine once complete. “Colin said he’d be able to map that no problem - with all the standard electronics removed it would be like any other four-cylinder turbo engine,” says Paul. “It still meant I needed a fuel return line, a swirl tank in the boot, high pressure pump and I had to modify the standard fuel tank too.”
Luckily, the VXR featured a hydraulic clutch system, just like the Mini, to make things slightly simpler there. Also, unlike the XE engine, the new replacement has a cable-operated gear shifter, so that part was easier to graft into the build. But that’s more-or-less the easy bits summed up! “The hardest thing of all was sorting out the windows,” adds Paul. “Tony at ACW helped with the polycarbonate side and rear windows once I’d sorted out hardboard templates, but the front, well that was a pain. I’d lost a few windscreens at glass specialists who’d apparently be able to cut it down no problem, then eventually gave up and thought I’d try it myself.” The first didn’t go to plan, but in the end Paul managed to successfully trim a standard screen down in the garage with a fine cutting disc on an angle grinder. It then took about a day of struggling to squeeze it into the trimmed-down rubber.
GOING FOR BRONZE
Paul had sprayed cars before at home, and following that DIY ethos, had no plans to splash out on a fancy paint job. “It only cost me around £300 to paint the car,” he says. “I decided to go with cellulose paint, as it’s easier to spray at home and gives a more ’70s finish. I mean, it’s not perfect but it polishes up well.” On the roof surrounding the Webasto, Paul opted for an equally retro vinyl cover, bonded in place. Contrasted with the black bumpers and wheels, it’s a striking look.
The first appearance was planned for the Irish International Mini Meeting in 2017, but life and a few technical glitches with the mapping saw the deadline delayed until the following IMM in Portugal. And no, before you ask, it wasn’t driven all the way to Portugal for the first run, but did see some driving around the local roads whilst there. “It had so much attention from the foreign Mini owners especially, as I don’t think you can modify a Mini like this in many European countries,” says Paul. “People were asking all sorts of questions, even laying in the road to take photos of it as we drove around!”
Now back in the UK for the foreseeable future, it seemed only right for me to pop home and take this mad creation for a spin, for the benefit of all
Mini Magazine readers, of course. At the time of the photos, the boost was wound
right down, as it needed a final few hours on the rolling road to perfect the mapping. But with well over 200bhp, this thing is already monstrous.
Gently off the clutch, which takes some getting used to as you’re virtually sitting on the floor, and we’re off. First or second work fine to get gingerly off the line and gradually the confidence builds. As does a false sense of security that this can be driven like a sensible car for sensible people. That’s quickly dispelled by the rock-hard ride, bright yellow paint and the fact you can see the traffic lights more easily through the sunroof than the windscreen. Building
“I don’t think you can modify a Mini like this in many European countries”
confidence now with every blip of the throttle and subsequent dump valve woosh-tsshh when it arrives a roundabout and clear stretch of A-road. Keeping the thing firmly in a straight line, unleash hell as the front tyres light up through third, fourth, fifth...that’s quite enough thanks! Drive back home, absolutely buzzing with adrenaline, but with an urge to respectfully hand it back to the zoo keeper before it bites.
Paul, however, is understandably happy to have dodged the test drive, checking the temperatures and having a quick once-over before popping it back in the garage. Actually, he doesn’t really drive the Mini that often himself now it’s actually complete. “The thing is, now I’ve done what I wanted to do with the car,” he concludes, “that’s it - I’ve done it. I’ve been working on it for so long, I fancy a change of scene and a new project.”
Whether Paul sells up for an early Mini restoration or harks back to his custom car days is yet to be seen, but we share a family eBay account and I’m keeping a beady eye on him!
Classic bucket seats with Luke four-point harnesses looks the part.
Paul’s Clubman is certainly striking after losing that 5.5-inches.
Unusual Compomotive five-spokes.
Stripped out interior works on this Clubman.
Steering wheel is removable.
RaceTech digital speedo in standard location.
Extra boost and temperatures gauges.
Paul skilfully trimmed the windscreen down himself!
After much fettling, the MkV Vauxhall Astra VXR engine fits and produces a very...
Astra radiator and swirl tank live in the boot.
Boot lid and bonnet are fibreglass items.
1970s full-length electric Webasto sunroof.
Shortened wipers go with cut windscreen.
Silicone boost hoses poking out the bonnet.
Vents are for the benefit of the enclosed rad.