We've all done it, right? Mused over the what ifs - cars that we, as enthusiasts, wish manufacturers would build. That's exactly how this Smit Vehicle Engineering Oletha coupe came about. Only rather than stopping at idle discussion, brothers Kaess and Willem Smit, set about properly exploring the idea of a BMW Z8 coupe. Both BMW fanatics, their family history is littered with some choice cars, and having been gifted the opportunity to remove some panels on his E86 Z4 M Coupe - via a track-day off - Willem discovered the task was relatively simple. Or simple for an automotive engineer, at any rate; his CV includes stints at Tesla and Singer, work experience that dovetails rather neatly with Kaess's expertise in aerospace composite materials.
The Z8 idea promptly grew wings. Frame drawings were done, the Z4's dimensions being considered close enough to work, particularly in relation to the wheelbase. There were other advantages, too - not least cost and availability, but also rigidity. The low volume Z8 might be beautiful but it's never been particularly well regarded as a driver's car. The newer Z4 benefits from being developed as a roadster first, meaning the later coupe made the Z8 look structurally flaccid in comparison. The influences on the Oletha, then, are limited to its looks, which means there's a retrospective nod to the 507 Roadster, too. And the result? Make up your own mind, but in reality it's absolutely gorgeous, even if the black does smother its finest details in pictures.
Dynamically, the brothers intended to elevate their interpretative model to another level altogether, aiming at something more akin to a 996 Porsche 911 GT3 than BMW's boulevardier Z8. As such, there's KW adjustable suspension attached to its bespoke, forged, monoblock aluminium wheels, which here wear Michelin Pilot Sport 4S tyres. The brakes are AP Racing six-piston Radi-Call Pro5000R calipers up front on 355mm floating discs, the rears being four-pistons with 340mm discs. There's a mechanical limited-slip differential and a six-speed manual transmission attached to the S65B44 4.4-litre naturally-aspirated V8. That's a significant diversion from the Z4 M's standard S54 straight-six, of course, and it's required not insignificant work to get it to fit under the bonnet.
Commendably they've achieved that, 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 passes through the manifolds. Smit engineering it in such a way that it can build cars for both right- and left-hand-drive markets, while that functional hood scoop is required to give an additional 20mm of clearance. Should you wish, Smit will build you an Oletha with a straight-six that does without that scoop.
The finish under the bonnet of this S65-engined 'prototype' reflects that of the body, which is to say that it's as good as - if not better - than the quality you'd expect of an OEM. The attention to detail is remarkable, and it speaks not only to the level of passion that's gone into it, but also the engineering nous required to make sure that everything looks good while doing its job impeccably well. The Oletha is unquestionably a testament to the men who built it
The body isn't just beautiful either, it's also constructed entirely from carbon fibre. Being based in San Diego, Smit, understandably, tried several US suppliers before heading to the UK and sourcing its panels there, being quick to point out that they couldn't find a US supplier to build panels to the quality they demanded. Over here they had the luxury of choice, settling on one in the south of England. Exactly which one they're not prepared to say; likewise, the final surface modelling of the Oletha was undertaken by an 'industry expert', though the overall shape is the brother's design.
That composite body is fitted using the factory mounting points and utilises differing panel thicknesses and laminates depending on location, structural requirements and their aerodynamic loading. Computational testing revealed the new body without a spoiler produced lift at the rear, so there's a pop-up affair to counter it, reducing lift by 350lbs over the rear axle at 200mph. As is apparent when speaking to the brothers about every area of the Oletha build, they explored all possibilities, looking at a number of alternatives before this system was adopted. And to be certain of its longevity they went to the trouble of load testing the mechanism, building a carrier for it and tasking Willem's girlfriend to do 10,000 step-ups on it. That's commitment for you - especially given the mechanism is from another production vehicle. They just wanted to be sure.
After the svelte, hyper-detailed exterior, the Oletha's interior comes as a bit of a surprise. It's pretty much standard, though there's the option of different seats, improved audio and differing trim materials as per the customer's wishes. Here the brothers' engineering pragmatism is that it all works, and they're not wrong. Indeed, the standard dash does a fine job, the deep cowled instruments with proper dials, the wide transmission tunnel still with its stubby gearlever and the stock BMW steering wheel are all a reminder of how simple, and uncomplicated, car interiors used to be.
Starting the engine reveals that Smit Vehicle Engineering has done more than merely slot BMW's stock V8 under the bonnet. Its bespoke carbon fibre manifold obviously helps change its character, but there's more to it than that, with forged pistons and conrods, and uprated valve springs fitted. 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 sounds fantastic - an intriguing mix of Germanic culture and US muscle, which, given the Oletha's genesis seems entirely appropriate.
There's an immediacy to the engine's response that's hugely appealing, too, and the Oletha does a very convincing job of covering ground with impressive composure. It feels sophisticated at pace, in a manner that initially gives the impression of a talented GT. The gearshift is wonderfully positive, the lever moving across its gate easily, and such is the engine's ample urge up to about 5,000rpm, you can make rapid progress with little effort.
Ask more, though, and the Oletha's character changes. The engine takes on a harder-edged note, its delivery correspondingly more ferocious, and the chassis, so fine-riding and able, 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 something like a 911 GT3, it's probably all the better for it. Its bandwidth is broader, and much more liveable. Which isn't to say that it's not hugely engaging; on the canyon roads near Palm Springs where we spent a few hours wringing out the V8, every second in the driver's seat was a joy.
Despite accommodating a bigger engine under the long bonnet, the Oletha's nose still turns in swiftly and accurately, Smit revealing that the weight distribution is within 0.1% of 50/50. If that weren't impressive enough, the kerbweight, when fully fuelled, is said to be 1483kg, which is in the same ballpark as BMW's quoted figure for the standard car - which obviously makes do with six cylinders. Consequently, the brakes take a beating all day without running out of ideas; reassuring, when you consider the performance on offer. It also speaks to the amount of testing its creators have done to make sure everything functions just so. The overall feeling is of a car that's been lovingly engineered, and it's no coincidence that the Oletha is as remarkable to drive as it is beautiful to behold. The brothers say it's the car they wish BMW had built and it's hard not to concur. What's even more incredible is that it's not just the product of a pair of talented engineers' musings, but also the first incarnation of them. Imagine what they'll think of next.
SPECIFICATION | SVE OLETHA
Engine: 4,361cc, V8
Transmission: 6-speed manual, rear-wheel drive, LSD
Power (hp): 450@8,300rpm (standard M3 GTS)
Torque (lb ft): 325@3,750rpm (standard M3 GTS)
0-62mph: c. 4 seconds
Top speed: c. 180mph
Weight: 1,483kg (with 100 per cent fuel)
MPG: 22.2 (standard M3 GTS)
CO2: 295g/km (standard M3 GTS)
Price: c. $450,000
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