BMW M5 E39 DCT-swapped machine

BMW M5 E39 DCT-swapped machine

While the E39 M5 is an awesome super saloon, transforming one into a full-on track machine is more work than most people would be willing to put in. But, as you can see, the owner of this hardcore build has done just that, and he’s created a devastatingly capable track-day monster.

Words: Elizabeth de Latour

Photos: Simmy Photography


The E39 M5 is probably not the first car you think of for a track build, but that’s exactly what this hardcore, DCT-swapped machine is, and it’s simply epic.

BMW M5 E39 DCT-swapped machine

The E39 M5 is a lot of things to a lot of people, and to many of them, it is the ultimate M5. It has the purity of the six-speed manual gearbox, the surging power of the S62 V8, and the sublime chassis that effortlessly blends divine handling with supreme comfort, all wrapped up in an understated and elegant package that still looks great today. It’s no wonder that prices are so strong and desire is so high. And while it is a sublime road car, it is also more than capable of impressing on track.

The 4.9-litre S62 V8 has been enhanced with custom intakes and Russ Fellows exhaust manifolds

BMW M5 E39 DCT-swapped machine

But a track car, it is not. It’s quite big and heavy, a little soft for the circuit, and you’d have to be incredibly committed to decide to try and take a luxury performance saloon and turn it into a full-on, hardcore track machine. Which is exactly what Paul ‘Steaky’ Westinghouse (@m5tracktoy, YouTube: Westinghouse Productions) decided was the most sensible course of action for his M5. However, when it comes to this build, there’s more than meets the eye on so many levels, and it’s truly on another level.

First up was a diet. I started stripping out approximately 340kg of weight by removing anything and everything that wasn’t needed

In some ways, it’s not surprising that Paul was drawn to the E39 M5 – in his day job, he’s used to handling heavy machinery with some serious horsepower, and that’s because he’s a freight train driver, as well as an instructor and assessor, and, in his own words, a “general savant of the railway.” And while Paul is clearly a fan of all forms of transportation, cars, and BMWs in particular, have played a big part in his life from a young age.

“My interest in BMWs started when I was around 10. My old man bought himself a 1988 E28 525e. That sharknose and long bonnet were iconic and made any 5 Series stand out from the crowd, irrespective of the specification,” he recalls with a smile. “My first BMW was an E30 325i Sport in Dolphin grey metallic. It was a tail-happy rust bucket, but was an absolute hoot to drive,” chuckles Paul.

BMW M5 E39 DCT-swapped machine

With a taste for BMWs established and after owning a couple of E39s, it was only natural that he would progress up the ranks, and he had his eye on one model in particular.

“I always wanted an E39 M5 since seeing the advert in 1999 for them. Those sleek lines, quad exhaust outlets and an understated-looking executive saloon just ticked the boxes,” he enthuses, and ownership was inevitable. “In around March 2015, the lure of the M5 started to take hold,” Paul says with a smile. “At that time of looking to buy one, they were in abundance, and prices ranged from £5k to around £10k depending on what you were looking for and how much it had been abused. Trawling Autotrader, this was the fourth car I’d seen, and I took the risk of travelling 200 miles to view it with cash in a backpack. It had been looked after all its life with a massive stack of paperwork documenting all service and maintenance work over the years and, more importantly, had zero rust or corrosion on it in any of the usual places. I wasn’t disappointed after inspecting it and drove home happy. Very happy,” he grins, adding: “I got lucky and gave £7500 for this one,” and we only wish we’d put our money into an E39 M5 back when prices were so low…

Paul enjoyed his M5 sparingly, covering fewer than 1000 miles a year, and that might well have been the end of the story – man buys M5, man enjoys M5, the end. But things suddenly took a turn for the worse, and the M5 was going to have a new role to play in Paul’s life.

BMW M5 E39 DCT-swapped machine

“At the end of 2018, I started to suffer a bout of ill health and needed something to give me focus and direction again,” explains Paul. “It was decided to turn the M5 into a dedicated track car, which meant a lot of work, but most importantly, it gave me a reason to live, and the new project began,” he says. The M5 was about to go from garage ornament to hardcore track build, though it certainly wasn’t going to be an overnight process.

“First up was a diet,” explains Paul, with the M5’s substantial weight needing to be substantially reduced if it was to become a track car. “I started stripping out approximately 340kg of weight by removing anything and everything that wasn’t needed – all the interior, sunroof, wiring looms for audio and ancillary items, exchanging the bonnet and boot for carbon fibre items, fitting a fibreglass sunroof panel, lightening the bumper strengthening bars by drilling the heavy cast aluminium items with large holes along their length etc.” That is a serious weight loss course and took the M5 from around 1800kg to under 1500, which is a vast difference, and transformed it from heavyweight to what counts these days as a light car. “The list was endless, as was the modification list that was about to start…” adds Paul, and he was only just getting going with this build.

“Once the weight was removed and parts sold off to fund the next phase, HSD Monopro coilovers were fitted, as were lightweight alloy wheels with semi-slick road-legal tyres, and a 3.85:1 diff ratio change for brisker acceleration, PB Brakes 380mm fully floating front discs with eight-piston calipers and BTCC-spec Project MU pads. A Pleie-Sport full FIA-approved roll-cage, Corbeau bucket seats and TSW four-point harnesses, an OMP Alcantara dished steering wheel and a few other things were fitted too to give it the safety and support to make it a capable car on track,” says Paul. In addition to those essentials, the dash has been flocked, blue trim strips have been added, and there’s a custom switch panel as well.

With so much weight removed and serious brakes and suspension on board, the E39 M5 was like a completely different car, and Paul was extremely happy with all his hard work. “This was great, and I enjoyed a year on track like this with it mainly doing laps of the Nürburgring and Donington Park,” he grins. “A set of Russ Fellows exhaust manifolds were installed to allow the engine to breathe easier, and a customdesigned cold air intake system complemented them. The difference in mid-range to topend engine power was instantly noticeable as the engine didn’t feel like it was being strangled.”

At this point, things were going great with the M5, but everything else was about to go wrong. “A little world event happened, and nobody was allowed out to play!” chuckles Paul, but every cloud and all that… “This gave me the chance to go for the next big project with the car, and I started doing a bit of research about fitting a DCT gearbox. A lot of research was done, and the concept was simple – flappy paddle gear shifting, which would let me keep both hands on the wheel and not worry about being in the wrong gear and risking a money shift on track,” he explains. It makes good sense, but this was going to be a serious international undertaking.

“Parts were obtained as and when we were allowed out of the house,” Paul tells us, reminding us how strange life was just a few years ago. “A GS7D36SG gearbox from a crashed 2019 F82 M4 and a one-piece carbon fibre propshaft were bought from eBay. An adaptor plate and new flywheel were commissioned from Adamat Performance in Poland to allow the gearbox to be mated to the S62 engine,” he says, giving us an insight into the engineering involved. “The carbon propshaft had the original steel drive flange removed and a flange yoke friction-welded on by a local specialist, and then a gearbox cradle was made in the workshop to support the weight of it. Mechanically, it was a very easy installation, but electronically, it was a nightmare,” Paul grimaces.

“I opted to use a product called the GCU, but after six months of frustration and trouble to get it somewhat usable, I was never happy with it. Firmware updates came and went for the GCU, and it got a little better each time, and I eventually found a firmware update that didn’t try locking two gears together at the same time or burn the clutch baskets out,” he says. That was a massive amount of work to get the DCT fitted and functioning correctly, but all of Paul’s efforts were absolutely worthwhile.

“At this point, it was mid- 2020 and track days were once again back on the menu, as were trips back to the Nürburgring, albeit with restrictions imposed due to the pandemic,” he says. “A few years of hard work had started to pay off, and the car was behaving as I intended on track, and the DCT gearbox was worth the effort,” Paul says with a smile. “With the 3.85:1 final drive, it allowed the engine to be in the peak power band at the right time in the right gear when needed. Top speed was back at 180mph due to seventh gear in the DCT box (with the original 420G six-speed, top speed was reduced to 150mph with the higher final drive), but the aero kit and Geoff Steel carbon GTR rear wing meant air drag limited the speed to 160mph, which was easily achieved with stability and sure-footedness. With the weight down to 1590kg with a full tank of fuel and driver, it means that the heavyweight executive saloon can perform in ways it wasn’t really meant to,” Paul grins.

“While on the first trip of 2023 to the Nürburgring for the Circuit Days track day, Misha Charoudin jumped onboard for a lap for his YouTube channel. He was impressed and surprised at how quick the car was. His comment: ‘It feels slow as it’s so stable, but then you look over at the speedo and see it at over 140mph, you realise how quick it is,’ summed up the car – quick, capable but comforting and reassuring,” enthuses Paul, and all his hard work and dedication has absolutely paid off.

This E39 M5 is a simply staggering build. Paul’s focus over four years in turning an E39 M5 into a track build was so absolute that the end result was only ever going to be something absolutely awesome. It might seem hard to believe, considering where he started from, but he’s created an absolutely epic track weapon out of a car that simply has no right to be this capable. Sure, life would have been much easier if he’d started with something smaller and lighter in the first place, but it would have been a far less eventful journey, and the sense of accomplishment would have paled in comparison. The most impressive part of this build is, without a doubt, the gearbox swap, and it’s also Paul’s greatest achievement.

“My favourite modification on the car is the DCT gearbox – it transformed the way the car drove (once it was working satisfactorily) and allowed me to concentrate on the track without worrying about a money shift,” he says with a satisfied smile. But when we pitch Paul our money-no-object mods questions, his reply throws us for a loop. “I wouldn’t have done any mods – hindsight would suggest that leaving it standard would have been best,” he says with a smirk. Not that he’s about to listen to his own advice, though… “Nothing lasts forever, and upon return home from the ’Ring, the decision was made to strip the car for parts and start a new project – an S62 DCT E46 M3 track car. This project is underway at the moment and will be a long, long time in the making,” says Paul. But he’s not a man to rush things, he’s happy to take his time and get it right because that gives you serious results. While on the one hand, it’s a shame that the E39 M5 has lapped its last circuit, on the other hand, Paul’s new creation promises to be even more full-on and thrilling, and the M5’s legacy will live on as one of the wildest and hands-down awesome E39s we’ve ever witnessed.

With the weight down to 1590kg with a full tank of fuel and driver, it means that the heavyweight executive saloon can perform in ways it wasn’t really meant to

The M5’s exterior has been dictated by aerodynamics and weight-saving.

The interior has been completely stripped out to help get the M5’s weight down as much as possible; it took a lot of work to get the DCT gearbox operating properly, but it was worth it as it’s perfect for the track


  • ENGINE AND TRANSMISSION: 4.9-litre V8 S62B50, custom air intakes, Russ Fellows exhaust manifolds. Getrag GS7D36SG seven-speed DCT gearbox, custom gearbox cradle, Adamat Performance adaptor plate and flywheel, GCU, carbon fibre onepiece propshaft, 3.85:1 final drive
  • CHASSIS: 9x18” (front and rear) Cades Artemis wheels with 265/35 (front and rear) semi-slick road-legal tyres, HSD Monopro coilovers, E53 X5 rear anti-roll bar, PB Brakes eight-piston calipers with 380x32mm fully floating discs (front), Brembo four-piston calipers with 370x28mm discs (rear)
  • EXTERIOR: Carbon fibre bonnet, 12mm front splitter, glass sunroof and mechanism cassette removed and fibreglass panel fitted, carbon fibre boot lid, Geoff Steel Racing carbon fibre GTR rear wing, flat floor and aluminium full-depth rear diffuser
  • INTERIOR: Completely stripped interior, flocked dashboard, OMP Alcantara dished steering wheel, Corbeau bucket seats, TRS Magnum four-point harnesses, Pleie-Sport FIA-approved roll-cage, custom switch panel, blue fabric trims
  • THANKS Anyone who’s put up with me – I’m sure there will be a lot of you out there, especially Elizabeth, the editor, for waiting for this to get done, and Northern Rail Ltd and Neville Hill T.R&S.M.D for allowing the railway depot to be used for the photoshoot
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