We’ve all done it, haven’t we? Thought about the assumptions – cars that we as enthusiasts want manufacturers to build. That’s exactly how this Smit Vehicle Engineering Oletha Coupe was born. Rather than stop at a pointless discussion, the Kaess brothers and Willem Smit set about properly exploring the idea of a BMW Z8 Coupe. Both BMW fanatics, their family history is littered with choice cars, and having had the opportunity to remove some panels from his E86 Z4 M coupe – via a track day – Willem found the task relatively simple. Or simple for an automotive engineer, anyway; his resume includes stints at Tesla and Singer, work experience that fits quite well with Kaess’ expertise in aerospace composite materials.
The idea of the Z8 quickly grew wings. Chassis drawings were made, with the dimensions of the Z4 considered to be close enough to run, especially with respect to the wheelbase. There were other benefits as well – including cost and availability, but also rigidity. The low-volume Z8 may be good looking, but it’s never been particularly well regarded as a driver’s car. The new Z4 benefits first from being developed as a roadster, meaning the later coupe made the Z8 look structurally saggy in comparison. Influences on the Oletha are therefore limited to its appearance, which means that there is also a retrospective nod to the 507 Roadster. And the result? Make up your mind, but in reality, it’s absolutely stunning, even if the black smothers its finest detail in pictures.
Dynamically, the brothers intended to elevate their interpretive model to a whole new level, aiming for something closer to a 996 Porsche 911 GT3 than BMW’s boulevardier Z8. As such, there’s KW adjustable suspension attached to its bespoke one-piece forged aluminum wheels, which here wear Michelin Pilot Sport 4S tyres. Brakes are AP Racing Radi-Call Pro5000R six-piston calipers up front on 355mm floating discs, with the rears being four-piston with 340mm discs. There’s a mechanical limited-slip differential and six-speed manual transmission attached to the naturally aspirated 4.4-liter S65B44 V8. It’s a significant diversion from the Z4 M’s standard S54 straight-six, of course, and it takes some not inconsiderable work to get it under the hood.
Luckily, they succeeded, with Smit’s approach requiring 3D-printed engine mounts and unique manifolds; the latter alone taking over 25 different iterations to perfect. It’s so tight in the engine bay that the steering column goes through the manifolds. Smit designed it so it could build cars for both right and left hand drive markets, while that functional bonnet scoop is needed to give an extra 20mm of clearance. If you want, Smit will build you an Oletha with a straight six that dispenses with this scoop.
The underhood finish of this S65-powered “prototype” mirrors that of the body, meaning it’s as good as – if not better than – the quality you’d expect from an OEM. The attention to detail is remarkable, and it’s a testament to not only the level of passion that goes into it, but also the technical know-how needed to ensure everything looks good while doing its job impeccably well. The Oletha is unmistakably a testament to the men who built it
The body doesn’t just look good either, it’s also built entirely out of carbon fiber. Being based in San Diego, Smit understandably tried several US suppliers before heading to the UK and sourcing panels there, quickly pointing out that they couldn’t find an American supplier to build panels of the quality they demanded. Here they had the luxury of choosing, settling on one in the south of England. Exactly which they are not prepared to say; likewise, the final surface modeling of the Oletha was undertaken by an “industry expert”, although the overall shape is the brother’s design.
This composite body is mounted using the factory mounting points and uses different thicknesses of panels and laminates depending on the location, structural requirements and their aerodynamic loading. Computer testing revealed that the new spoilerless body produced lift at the rear, so there’s a pop-up case to counter it, reducing lift by 350 lbs on the rear axle at 200 mph. As seen when talking to the brothers about every area of Oletha’s build, they explored every possibility, considering a number of alternatives before adopting this system. And to be certain of its longevity, they went to the trouble of testing the mechanism under load, building a stand for it, and charging Willem’s girlfriend to do 10,000 steps on it. It’s a commitment for you – especially since the mechanism comes from another production vehicle. They just wanted to be sure.
After the svelte and hyper detailed exterior, the interior of the Oletha surprises a little. That’s pretty much standard, although there’s the option of different seats, improved sound and different trim materials depending on the customer’s wishes. Here, the brothers’ engineering pragmatism is that everything works, and they’re not wrong. Indeed, the standard dashboard does a good job, the deep-hooded instruments with appropriate dials, the wide transmission tunnel still with its chunky gear lever and the original BMW steering wheel are all reminders of how well the interiors of car were plain and simple.
Starting the engine reveals that Smit Vehicle Engineering did more than just put BMW’s stock V8 under the hood. Its bespoke carbon fiber manifold obviously helps change its character, but there’s more to it, with forged pistons and connecting rods and upgraded valve springs. It uses BMW’s MSS60 engine management, with Smit claiming a conservative 450hp at the crank and the redline raised to 8,500rpm. Combined with its custom exhaust, it looks fantastic – an intriguing mix of Germanic culture and American muscle, which, given Oletha’s genesis, seems quite fitting.
There’s an immediacy to the engine’s response that’s also hugely appealing, and the Oletha does a very convincing job of covering ground with impressive composure. It feels sophisticated to the beat, in a way that initially feels like a talented GT. Shifting is wonderfully positive, the lever moving easily on its gate, and such is the engine’s ample thrust up to around 5,000 rpm you can make rapid progress with little effort.
Ask for more, however, and Oletha’s character changes. The engine takes on a harsher note, its delivery is commensurately fiercer, and the chassis, so thin and capable, responds positively to the greater demands placed on it. There’s agility and poise beneath the refinement, and while it’s not as sharp or as edgy as a 911 GT3, it’s probably even better. Its bandwidth is wider, and much more livable. Which isn’t to say it’s not hugely engaging; on the canyon roads near Palm Springs where we spent a few hours tweaking the V8, every second in the driver’s seat was a joy.
Despite packing a bigger engine under the long hood, the Oletha’s nose still turns quickly and precisely, with Smit revealing that weight distribution is within 0.1 per cent of 50/50. If that wasn’t impressive enough, the curb weight, when fully fueled, would be 1483kg, which is in the same ballpark as the figure BMW quotes for the standard car – which obviously settles for six cylinders. Therefore, the brakes take hits all day long without running out of ideas; reassuring, given the performance offered. It’s also a testament to the amount of testing its creators have done to make sure everything is working properly. The overall feeling is of a car that’s been lovingly crafted, and it’s no coincidence that the Oletha is as great to drive as it is to look good. The brothers say it’s the car they wish BMW had built and it’s hard to disagree. What’s even more amazing is that it’s not just the brainchild of a talented engineering couple, but also the first incarnation of them. Imagine what they will think next.
SPECIFICATION | SVE OLETHA
Motor: 4361cc, V8
Transmission: 6-speed manual, rear-wheel drive, LSD
Power (hp): 450 to 8,300 rpm (standard M3 GTS)
Torque (lb ft): 325 to 3,750 rpm (M3 GTS standard)
0-62mph: vs. 4 seconds
Top speed: vs. 180mph
Weight: 1483 kg (with 100% fuel)
MPG: 22.2 (standard M3 GTS)
CO2: 295g/km (M3 GTS standard)