• Unleashing the Beast Supercharged E39 M5

    The E39 M5 is still a fantastic performer, even more so when its packing a supercharger. The E39 M5 has always been a wonderful performer but thanks to a full rebuild and a supercharger conversion this one feels factoryfresh and wondrously rapid. Words: Adam Towler. Photography: Gus Gregory.

    Stunning supercharged #BMW-E39 / #BMW-M5 / #BMW-M5-E39 / #BMW-E39 / #BMW / #BMW-M5-Supercharged-E39 / #BMW-M5-Supercharged / #BMW-S62 / #S62-Supercharged / #S62B50

    The E39 M5 does brooding. Those M5s that have succeeded it may have offered more power, faster acceleration, and much more electronic gadgetry but that latent kerbside menace, dished up in spiteful quantities by a ubiquitous Carbon black E39 still can’t be toppled. Then there’s the purity of the mechanical recipe: it seems the debate grows ever stronger around cars that do most of it for you and those that put the driver in the centre of the action. Who’s to say who is right or wrong on this subject, but three pedals, a gear lever, and a glorious naturally aspirated V8 will always define the E39 M5.

    Take a look at this particular M5. It has the brooding thing down to perfection, and while at first glance it might not be obvious why, there are a few details that enhance that quality. Study the front wheels, for example, and note how they fill the arches so convincingly; observe the little lip spoiler that ties the front down to the ground. And listen too, if only you could of course, to the industrial throb that’s being emitted from those quad tailpipes: loud, but not too shouty. Not crass. Just menacing. I don’t know about you but the sense of anticipation for me has already just broken the gauge.

    This car is the work of a company called WaffZuff, a contraction of Waffen-aus-Zuffenhausen, and specifically of a man by the name of Raikku. He’s well known in M car circles (and in the world of Porsche, hence the company name) and E39 M5s are something of a speciality.

    It’s quite a sobering thought that the E39 M5 is now getting on for 18 years old (at least for those of us of a certain age). There are still quite a few haunting the mainstream classifieds but many are in need of substantial work as they reach the end of their ‘first’ lives. A tired E39 M5 has all the potential of a major financial headache for the unwary. That means when WaffZuff carry out a project such as this one, there’s as much restorative work going on as there is tuning. Take this actual car, which required the refresh of almost every component, and included a new engine block into the deal.

    In fact, this car has the last available new right-hand-drive engine block from the factory, according to Raikku. The engine was built up from there, with components bead blasted first, then plated or powdercoated to look factory-fresh. Every sensor from the oil level at the bottom to the throttle position sensor at the top has been replaced, along with other items such as the water pump. Where rebuilding was more practical, that too has taken place, such as with the alternator.

    The heart of this conversion is an RK Autowerks Stage 2 supercharger kit, comprising a Vortech V3si ’charger, intercooler, carbon fibre plenum and pipework, and high-flow injectors, amongst other items. This has been teamed with exhaust manifolds, race-spec cats and a custom map, all from Evolve.

    The result is a standout figure of 620hp and, perhaps even more importantly, over 500lb ft of torque. Naturally, the work on the car doesn’t end there. The engine is connected to the drivetrain via a carbon/Kevlar clutch with a single mass flywheel that Raikku has made back in Germany, while the differential is now a custom 40 per cent locking unit. The gear mechanism has benefitted from a short-shift kit more usually found in an E60 545i, while those exhaust pipes just visible at the rear betray the Hamann back boxes fitted.

    Bilstein B8 dampers and Intrax springs now suspend this M5; Raikku tells us, “every bit of the suspension was rebuilt and plated”. Powerflex bushes are used throughout, and the rear differential carrier has been reinforced to cope with the mayhem unleashed at the rear wheels. The front brakes now feature #BMW-Performance calipers and discs designed for the E90 Series cars, but with WaffZuff custom caliper brackets. A set of rear M5 rims are now also used on the front axle, hence that broadshouldered look clearly visible in the photos. This means the standard eight-inch front rims and their 245/40 ZR 18s are replaced with the 9.5-inch rear wheels and a 275/35 ZR18 tyre. Raikku’s not a big fan of understeer, it transpires.

    The only other obvious exterior modifications are the subtle rear diffuser and front lip spoiler from Slimmbones, plus the deletion of the front foglamps. That’s more than enough spec detail, though; it’s time for a drive.

    “It’s a bit of a handful”, says Raikku pensively. We’ve been talking about the 40 per cent locking diff specifically, but I can extrapolate that this might apply to the whole car. Particularly so given that we’re driving it in January, in temperatures just above freezing, and that the roads are smothered at this time of the morning with a layer of greasy near-frozen emulsion that has yet to be burned off by the enthusiastic but weedy sunshine. “Just keep it on the throttle until it’s straight again so it doesn’t have a nasty load change, because it is more aggressive,” Raikku advises. Understood.

    Among the numerous details tidied up by Raikku is a new seat cushion for the driver’s seat, which now locates my posterior into a cabin that may have aged in design but still looks so right to these eyes. I find it fascinating, and not to say a little bit depressing, that on the day I drive the WaffZuff car I happen to be driving around in a nearly new BMW M4, and the sheer quality of the old timer is blatantly obvious. I’m talking about the way the door closes and the noise it makes as it does so; the action of the switchgear, the feel of the materials, the way there isn’t one single rattle in this old car while the M4 creaks all over the place. I know the M5 is a class of car above but it really reinforces the impression that the latest products are very much built for the Personal Contract Purchase generation. I don’t know about you but I get a real kick out of simply being in something that feels as well-engineered as this old M5.

    The temptation is to mash the throttle into the carpet and feel all hell break loose, but I’m not going to. That would be more than a bit childish, and in these conditions, probably foolish, but I also want to get the sense of this M5 as a cohesive, or otherwise, car. It’s one thing to create a big sports saloon with 600hp in your workshop but what about the finer points of the conversion? I’m talking about low-speed drivetrain refinement, throttle sensitivity and progressiveness on part throttle and at different load points, ride quality, brake feel, even the acoustics. In some ways these are the even greater challenges, especially for a small company, to get right.

    And so I try to pull away from the WaffZuff workshop as serenely as possible and, via the petrol station, amble around this corner of Hertfordshire in as subtle a way as is possible while the oil comes up to working temperature. Raikku has already warned me that the lighter clutch and flywheel combination makes its presence felt, and that’s true, but it’s not to a great extent and apart from that it doesn’t feel much different to the experience of driving the standard car. The ride is really good, the engine docile but with the heavy thud of a potent V8 always in the background; the conclusion has to be that you could use this car every single day without issue. It’s always really rewarding to drive a car that responds exactly to how you drive it – good or bad. This car does, and that’s why it’ll always hold more appeal to me than an F10.

    Predictably, there is a massive Jekyll and Hyde moment approaching here and it is the single most hilarious thing about this car. One moment you can be driving around peacefully; the car is, in a way, quite relaxing because the drivetrain is smooth and the low murmur of the #V8 soporific. Then you squeeze in that torque and there’s a sense of the whole car snapping taut, of huge amounts of energy thrust upon the rear wheels. If there was dry asphalt beneath us I’ve no doubt it would accelerate with immense conviction, but instead today the DSC light flashes valiantly, nay, hysterically, and it’s obvious that a really sensitive right foot is required. When you can hook it up the car simply bounds down the road, with enough force to leave our photographer Gus giggling away and clinging onto his camera.

    That it is manically quick is patently obvious; you can either select a higher gear and use the torque, or really make things exciting and try and contain all that power in a lower gear. It certainly gives the driver many options on country roads and I have to keep reminding myself that fourth, even fifth, gear will suffice for the situation because there’s so much torque available, particularly when squirting between closely stacked corners.

    There’s no doubt the E39 M5 is a big chunky car. Its dimensions must be closer to a current 3 Series than an F10 5 Series, but at around 1800kg it’s much heavier and it does feel it, albeit not in a clumsy way. As you might expect, this car feels fresh and alert, and the extra grip generated across the front axle really gives you more confidence to push on that bit harder.

    It’s been too long since I’ve driven a standard E39 M5 to say for certain, but despite the low-grip surface it’s possible to lean on the front-end grip in a way I don’t think you could safely consider before. Whether it’s those wider tyres or the suspension changes that are responsible for the subtle improvement to the steering it’s hard to say for sure. It always has been the weak point of the E39 M5, due to not being able to fit the rack and pinion system of other Fives in the engine bay alongside the V8. However, there is a definitely a more connected feel to the way this car responds, perhaps borne from the slightly higher steering forces required.

    Does it go sideways on demand? Yes, of course. Almost anywhere, and on a day like today, in any gear. Get feisty with the accelerator pedal and the rears spin up instantly, but it’s a car you can get a hold of and really enjoy driving. The impression is that it won’t suffer fools. I think it’s safe to say that about any car that channels over 600hp through the rear wheels, but with the DSC off I find no nasty surprises and it’s hard to resist getting the tail moving through slow corners or out of junctions. With a car such as this one, you just have to.

    Raikku reckons it will cost around £45,000 to restore and then modify an E39 M5 to this level, including the purchase of the car. However, if you’re happy with Carbon black, you can buy this one for £31,000, via Waff Zuff.

    I’ve always held the E39 M5 in a near-saintly regard, and the thought of adding a large chunk of extra power by forced induction had my purist-led preconceptions nagging at me all the way to Raikku’s workshop this morning. The sheer duality of purpose of this car, and the potency of performance on offer, soon had them banished before you can say ‘and there’s wheelspin as I change up into fourth gear’.

    THANKS TO: Raikku at WaffZuff Tel: +44 7534 659055 Web: www.waffzuff.co.uk

    The DSC light flashes hysterically and it’s obvious that a sensitive right foot is required