While a 2JZ swap in something as hallowed as the E24 might seem like a cardinal sin, an 830hp single-turbo straight-six has totally transformed this classic 6 Series.

While modern BMWs are exceptional driving machines, loaded with some mind-boggling tech and delivering sensational performance, they just don’t have the same levels of style and appeal as the classic models. They’re incredibly capable but perhaps a little cold and soulless and we can’t imagine anyone will ever covet an F10 5 Series the way they might, say, an E24 6 Series. It has to be said that the E24 is not just one of BMW’s most instantly recognisable designs it’s also one of the most desirable cars it’s ever produced. It’s got that shark-nose styling that everyone still goes gooey over, a design that could never be recreated with today’s modern safety requirements, and it’s a car that just says ‘drive me.’ A Six is the kind of car that you want to take on a road trip, cruising in comfort and style while you soak up that seductive straight-six soundtrack. Or the kind of car you want to rip the engine out of, throw a turbo Japanese motor in there and go and do massive burnouts, that’s cool with us too.

BMW E24 6 Series stereo UI

Take a wild guess which of those options Otso Inna went for when it came to his E24. But we’re not even mad, because he’s got 830hp, and you can’t ever be mad about any car that has 830hp. It’s still a straight-six under that long bonnet and when you work 18 hours a day in a flipping goldmine you can pretty much do whatever the hell you want because that’s a real job, and when you come up and you see sunlight and your 830hp 2JZ-swapped E24 sitting there waiting for you, that’s the pay-off right there. Work hard, play hard, drive an 830hp E24 6 Series. Done.

BMW E24 6 Series engine close-up

Otso has sampled a variety of machinery over the years; it’s fair to say that he’s never been loyal to one particular make, kicking off his driving career with a Nissan Almera, later employing an E34 for daily duties and then getting a taste for modded turbo performance with a 570hp Mk1 Golf GTi, which we can’t imagine was a handful or anything like that at all. But, when it came to the E24, this was a car that he had wanted for a long, long time; “Once as a little boy I saw an E24 outside a shop and decided that someday I will get one,” he says and, three years ago, he made that childhood dream a reality when he purchased the E24 you see before you. It certainly looked smart, Otso tells us, having been treated to a respray and having had the interior re-trimmed in sexy Alcantara, but keeping it stock was never an option and he had plans. “It needed power and proper handling,” he explains, “but it also had to be suitable as a summer daily,” which certainly seems like a reasonable combination of needs, but then again most people don’t build a daily running a single-turbo 2JZ…

BMW E24 6 Series wheels

Everything on this car revolves around that engine, it’s the central focal point of the whole build, and it’s an epic power plant whichever way you look at it. Yes, if you look at it through the eyes of a BMW purist then there may be some scrunching of the nose and general disapproval, but really you can’t knock the 2JZ-GTE on any level. It’s a massively over-engineered engine, making an official 280hp (closer to 320hp in reality) and 320lb ft of torque thanks to a twin sequential turbo setup and capable of over 700hp on stock internals, making it the perfect choice for a big power build. Also it’s a straight-six, so it’s at least in line with BMW’s most iconic engine plus fitment should, on paper at least, be a little more straightforward as far as space is concerned.

BMW E24 6 Series rear-profile

Of course, simply slipping the 2JZ into the E24’s engine bay wouldn’t have sufficed, not when you live in Finland, home of many turbocharged monsters. Having sampled the pleasures of a 570hp VW Golf, even just a few simple bolt-ons weren’t going to be enough for Otso, and it strikes us that he is a man who believes in doing things properly. The famously unburstable 2JZ has been opened up for internal upgrades, and that is the sign of someone hunting for serious power. The engine has been fully-balanced and fitted with CP pistons, Eagle rods, Toolox main caps along with ACL bearings, while the head has been ported and equipped with Brian Crower cams, uprated springs and titanium retainers. You would expect to see a big turbo strapped to the side of that mighty straight-six and you will not be disappointed here, with Otso running a custom Holset HX50 JPSpro before switching to a Borg Warner S369, capable of developing somewhere in the region of 1000hp, and it’s mated to a custom made front-mount intercooler measuring 600x300mm along with a Tial blow-off valve. That much air flow needs a mighty amount of fuel to match, and so in the boot you will find an aluminium fuel cell connected to two Bosch 044 fuel pumps with -8 AN fuel lines, a Fuelab regulator and filter and, under the bonnet, a custom made fuel rail with six 2000cc injectors pumping a veritable waterfall of the good stuff into those hungry cylinders. An EcuMaster EMU standalone ECU takes charge of under-bonnet proceedings and there’s an RWN tubular exhaust manifold and a 3.5” exhaust running to a pair of pretty discreet tips that exit beneath the rear bumper. What all that means is that this 2JZ now produces a monstrous 830hp at 2.4bar of boost, along with a mighty 752lb ft of torque, which is a huge amount of power especially when it’s wrapped up in a 6 Series body, and just makes this car so utterly awesome.

BMW E24 6 Series front-profile

For the gearbox, Otso chose the ZF GS6-53DZ, which just trips off the tongue, and this is the same six-speed manual as you will find in the E60 and E61 530d, so it’s clearly a tough old ’box that’s perfectly suited to handling the serious power and torque outputs of his 2JZ, both of which are transferred to a type 210 LSD via a custom propshaft. The chassis upgrades, meanwhile, bring together the perfect blend of components to allow Otso to actually be able to enjoy driving his 6 Series and make use of all that power. Endowing the car with some proper handling was, as you will remember, high up on his list of priorities when he first purchased his Six, so a set of BC Racing coilovers has been fitted and employed to deliver a sizeable drop while the wide range of adjustment means the 6 Series now handles like a modern machine. Otso has also taken the step of fitting an E36 front axle, complete with rack and pinion steering, which offers up a much sharper helm than the standard car’s recirculating ball setup ever could, handy when you’re trying to precisely pilot 830hp down the road. That E36 front axle also means that when he was shopping for brake upgrades, E36 3 Series-compatible kits were his for the choosing and you will find a set of four-pot Outlaw calipers up front mated to M3 discs. Sitting on top of these you will spot the OZ Futuras and while they weren’t Otso’s first choice of wheels, they were the right choice. “My friend loaned me a set for Finland’s biggest car show while I was waiting for a set of wheels that I’d ordered, but which never arrived, to turn up,” he explains. “When I saw how good the Futuras looked under my E24, I had to buy a set” and that was a very good decision. These ones are 17s, fitted with Rimfix.fi polished lips, and they measure a reasonably meaty 8.5” up front and a seriously beefy 10.5” at the back, the rears having been wrapped in fat 275 tyres, essential when you’re trying to lay all that power down.

BMW E24 6 Series side-profile

When it comes to the car’s exterior and exterior, Otso has largely left it alone, and we have no qualms with that; the E24 6 Series is not a car you want to start messing with because it would be all too easy to ruin those perfectly-penned lines. We love the fact that this is another car finished in an unusual hue, that being Bronzite beige, and it is a sort of faded gold/bronze colour, but it works really well on the Six, it suits its shape and age and gives it even more of a sleeper look. The only exterior alterations, in fact, are the headlights, with Otso fitting a set of E34 ‘smiley’ items, but that’s it and this car really doesn’t need anything, it looks fantastic as is, especially with that wheel and fat tyre combo. Inside there have been a couple of very minor tweaks, the most major of these being the lush, Alcantara trimmed seats that he bought the car with, along with an M Tech steering wheel and Sparco metal gear knob and custom shifter assembly, and that’s it. No gauges, no dials all over the place, everything has been kept clean and neat and tidy, and we reckon it looks all the better for it. A Samsung phone mounted ahead of the gear lever and communicating wirelessly with the engine provides Otso with all the data he needs to keep a virtual eye on everything under the bonnet, and it’s a very neat all-in-one solution.

BMW E24 6 Series seats close-up

We love Otso’s E24, it is an awesome build, even though it doesn’t let on from the outside. The unassuming, beige looks are a big part of the car’s charm and appeal and there are few things more satisfying than creating an understated classic sleeper with enough power to blow anything on the road out of the water. But that’s not enough for Otso, oh no… “Next I want more power, everyone else has 1000hp,” he deadpans and he’s got the engine and the skills to make that happen. It’s taken him three years to get the car to where it is today, the first winter being spent tidying the car up, the second being used for the gearbox swap and the third winter dedicated to the engine swap itself. With winter rapidly approaching once more, we can only begin to imagine what sort of beast will emerge from Otso’s garage come the spring thaw…

BMW E24 6 Series interior wheel

Tech Spec: 2JZ-GTE E24 6 Series

Engine and Transmission

3.0-litre straight-six 2JZ-GTE by JPS Motors, fully-balanced, CP pistons (9:1 compression ratio), Eagle rods, Toolox main caps from KCNC/ Kenneth Eckert, ported head, Brian Crower cams, uprated springs, titanium retainers, ACL bearings, ECUMaster EMU standalone ECU with Sporttiauto dyno tune, fuel cell, twin Bosch 044 fuel pumps, -8 AN fuel lines, Fuelab regulator and fi lter, custom-made fuel rail, 2000cc injectors, Borg Warner S369 turbo (custom Holset HX50 JPSpro in photos), custom 600x300mm front-mount intercooler, Tial blow-off valve, RWN tubular exhaust manifold, 3.5” exhaust. Six-speed ZF GS6-53DZ manual gearbox, custom propshaft, type 210 LSD

Power

830hp and 752lb ft @ 2.4bar

Chassis

8.5×17” (front) and 10.5×17” (rear) OZ Futura wheels with Rimfi x.fi polished lips, 235/40 (front) and 275/40 (rear) Nordexx tyres, BC Racing coilovers, E36 front axle with rack and pinion steering, four-piston Outlaw calipers with E36 M3 discs (front) EXTERIOR Bronzite beige, E34 ‘smiley’ headlights

Interior

M Tech 1 steering wheel, original Recaro seats in Alcantara, Samsung phone for data display, Sparco gear knob and custom shifter assembly