- Post is under moderationSupercharged Z4 M Coupé / This supercharged Z4 M Coupé will blow you away!
Walk the line
Strapping a supercharged to the already potent Z4 M makes for an exceptional performance machine.
Words and photos Chris Nichols.
Tuning a car is often a fraught process. There’s the stress that comes from buying new products, not knowing if they’ll work until they’re on the car, despite your hours of research. There’s the possibility that the workshop you’ve chosen will do bad work or rip you off. And, of course, there’s the likelihood that fitting upgrades will simply expose weaknesses in other parts of the car you weren’t aware of, forcing you to spend money you hadn’t planned to.
Melbourne, Australia’s Kris Hooper knew about all those potential pitfalls when he chose his 2006 Z4 M Coupé. A tearaway in his younger days, he’d managed to destroy one car and blow two engines in another before getting a 1998 Subaru WRX sedan as his first proper performance car. However, his experience making mild mods to that, coupled with his otherwise methodical thought processes and focus on research, meant when he decided on something European to change things up, he wasn’t going to approach the project with anything other than highly considered plans to ensure he avoided many of those common tuning errors.
“Magazines and forums have taught me how easy it can be to perform a modification only to find you are not happy with the result, to not get enough bang-for-your-buck, or to find further down the track that it is incompatible with something else you have planned.” All this is why, before he even began, Kris had a pretty clear idea as to what he wanted and how to achieve it. The Z4 M base was already a great start – powerful, with great street handling and braking, and looks that Kris fell in love with well before the test-drive. But his desire for a true all-rounder that combined ability on the street with track prowess meant things had to be planned well in advance, particularly as, being such a rare car outside of America, parts were not exactly in huge supply. “Most of the parts I’ve used have come from the US,” Kris says, “simply because the number of E85 Z4s in the States makes production of go-faster bits viable.”
While in some respects, that lack of choice made things easy, Kris still needed to make the right decisions to achieve the goals he wanted, so on top of his research he talked to the guys at SouthernBM, a local and highly renowned specialist shop. The end result was a pretty tasty combination of American tuning parts, such as a 34-row Zionsville radiator, Vibra-Technics engine mounts, a StopTech Trophy BBK, Turner anti-roll bars, Hyperco Linear Race springs, Rogue Engineering rear shock mounts and adjustable rear control arms, and an APR Performance carbon GT wing. In fact, JRZ RS-1 dampers aside, the only brake and suspension parts Kris didn’t get from the US were the Vorschlag E46 M3 camber/caster plates and Carbone Lorraine R6E pads. Even inside, Kris relied on US know-how to help improve the already pleasant Z4 M cabin in the form of beautiful and custommade anti-slip pedals from Ultimate Pedals. To these he added a Recaro Pole Position bucket for himself and a ZHP-style weighted BMW gear knob.
Rather surprisingly, given the S54 engine is from the E46 M3, Kris had trouble finding options even here, specifically in the form of supercharger kits. At the time, only ESS kits were available, so to get the power he wanted Kris had no choice but to go with the company’s VT2-525 blower, intercooler and intake manifold kit. Currently it makes 403whp and 228lb ft of torque. Of course, ESS equipment is hardly second-best, and thanks to upgrading the included Setrab oil cooler for a bigger one, Kris reckons even now, with more options on the market, he wouldn’t change a thing.
Thankfully, Kris’s other engine tuning options were easier to come by. He decided on a beautiful Tekarbon carbon fibre engine cover to spruce up the bay, and a KSS Performance valve-controlled exhaust to allow him to stay street-legal and not annoy his neighbours on those early mornings when he heads to the track yet still enjoy the full metallic scream of the S54 when he gets there. And he’s there a lot.
In fact, thanks to holding onto his WRX for more practical driving, Kris can afford to use the Z4 as almost purely a toy. This freedom, combined with his desire to learn from instructors on a regular basis and to study his own on-board data stats, means he’s able to really enjoy the car at the Marque Sports Car Association (MSCA) sprint days he attends regularly. He actually won his class in both 2014 and 2015.
Not that it’s all been plain sailing on the way to the top. While Kris has generally been very careful to build the car in a holistic way, avoiding many of the pitfalls others fall into, there have been challenges and even a scary on-track moment coming from a rare lapse of judgement when it came to both on-track behaviour and the order in which he fitted his mods. In terms of the challenges, the biggest was getting rid of the stock suspension setup’s on-track understeer. “For a car that handled so well on the street, I wasn’t expecting so much understeer,” Kris says. “An additional strut brace didn’t help. Wider front tyres didn’t help. Additional front camber didn’t help much either. Nor did changing my driving style to add some extra trail braking. It wasn’t until I swapped the suspension to the current coilovers and anti-roll bars and was able to stiffen the rear relative to the front that I was able to get the car to rotate like it should.”
And that scary moment? That was the result of what turned out to be an unwise decision to head to Calder Park, a track with one of Australia’s longest straights, on stock brakes (albeit with nearly new pads) despite having fitted the supercharger kit. Now, in his defence, Kris says the brakes had been ordered at the same time but not arrived before the last-minute spot opened up. We’ll let him tell you what happened next: “Halfway through the day, the pedal was starting to feel a little sketchy, and I began a cool down lap so I could come in and inspect the pad material. Part way into that lap, though, a supercharged Honda Civic tore out of the pits ahead of me, and the red mist descended. About a minute later he was still in front as we hit the main straight. At the end of it, as we were both hitting 220km/h (135mph), some semblance of rational thought returned and I started braking slightly before my marker because of my earlier concerns. Too little, too late. Under my left foot I could feel little more than air. Brake pressure was non-existent.”
As he later learned after pumping a whole extinguisher into the front left caliper, the pad material had just crumbled away by that point, leading to piston seals melting and fluid spraying everywhere. Luckily he still managed to save it, steering the Z4 around the Civic and through the narrow gate at the end of the straight before spinning to slow down in the field beyond. Safe to say, the StopTechs went on straight afterwards!
One additional benefit of fitting the big brakes was that they necessitated a wheel change. Never a fan of the OEM design, Kris had previously chanced upon a forum member running Volk Racing G2s in the same matt black as his own Z4 and decided they were perfect. And, as luck would have it, a member of a different forum who lived locally was selling a set just when Kris needed them. “They must have been the only used set of wheels in the correct fitment available locally at the time, and possibly ever since,” he says. “I was so happy with them that when it came time to get a separate set of track wheels I went straight to Volk, who made me up a set of TE37SLs that, again, are exactly what I wanted.” It’s hard to argue with Kris’s choice, too.
Japanese wheels often look great on BMWs and this is no exception. The relatively rare G2 design’s sharp edges and rounded curves, especially, match perfectly with the E85 Z4 M Coupé’s similar mix of lines, keeping the car looking current and fresh, despite now being ten-years-old. And thanks to Kris’s focus on getting the handling, power and braking right, it’s now a car that doesn’t just look great but one he can enjoy driving for years to come (like his WRX, he has no plans to part with it though).
“The Z4 M, to me, represents a challenge, one that never gets old. There is such a fine line between getting it right and everything going to hell in a split-second. Sprinting along the right side of that line is one of my favourite things in the world.”
DATA FILE #Supercharged Z4 M Coupé / #ESS / #BMW / #BMW-Z4-M-Coupé / #BMW-Z4-M-Coupe-E86 / #BMW-Z4-M-E86 / #BMW-Z4-E86 / #BMW-E86 / #BMW-Z4 / #BMW / #Rogue-Engineering / #Vortech / #Volk-Racing-G2 / #S54B32 / #BMW-S54 / #S54B32-Supercharged / #S54B32-TUNED
ENGINE AND TRANSMISSION 3.2-litre straight-six S54B32 , #ESS-VT2-525 supercharger kit ( #Vortech-V3Si supercharger, #ESS intercooler and intake manifold), #K&N air filter, #Zionsville aluminium radiator, #Vibra-Technics engine mounts, #Tekarbon carbon fibre engine cover, #Bosch-453cc injectors, #KKS-Performance valve-controlled exhaust with push-button controller, KKS-Performance 4x80mm exhaust tips, software reflash to remove speed limiter and raise rev limiter to 8200rpm, six-speed manual gearbox
CHASSIS 8.5x19” ET+35 (front) and 9.5x19” ET+22 (rear) #Volk-Racing G2 wheels with 245/35 (front) and 275/30 (rear) Bridgestone Potenza tyres for the street, 8.5x18” ET+35 (front) and 9.5x18” ET+22 (rear) Volk Racing TE37SL wheels with 245/40 (front) and 275/40 (rear) Nitto NT-01 tyres for the track, JRZ RS-1 coilovers with Hyperco Linear Race springs (450lb front, 600lb rear), Turner Motorsport 30/25 E46 M3 anti-roll bars, stock front strut brace, Rogue Engineering adjustable rear control arms, Rogue Engineering rear shock mounts, Vorschlag E46 M3 camber/caster plates and perches, StopTech Trophy Sport BBK with six-pot calipers (front) and four-pot calipers (rear), 355x32mm two-piece slotted rotors allround and stainless braided lines, Carbone Lorraine R6E sintered endurance pads, Motul 600RBF fluid
EXTERIOR Carbon fibre centre grille (sourced by Turner Motorsport), APR Performance rear carbon GT wing, M Power windscreen decal
INTERIOR Recaro Pole Position race bucket (driver’s side only), Macht Schnell Competition Liteweight seat mounts, BMW ZHP-style weighted gear knob, LeatherZ leather door handle covers, custom billet Ultimate Pedals anti-slip racing pedalsStream item published successfully. Item will now be visible on your stream.
- Post is under moderationForecourt find #2007 / #BMW-Z4-M-Coupe-E86 (2006-2008) / #BMW-Z4-M-Coupé / #BMW-Z4-M / #BMW-Z4-E86 / #BMW-E86 / #BMW /
Now is the time to snap up the exclusive E86 Z4 M Coupé – before the few remaining cherished examples disappear. And you’ll do well to find a better example than this top-spec Ruby black 52k-mile 2007 car we spotted for sale at North East specialists Snippersgate.
With a recent set of Goodyear Eagle F1 tyres it boasts satellite navigation with the latest maps, heated seats, a factory upgraded Hi-Fi system, Individual champagne full leather upholstery and all the standard M kit. The requisite full service history includes the running-in service, whilst the asking price is a very reasonable £20,990.Stream item published successfully. Item will now be visible on your stream.
- Post is under moderationBMW CONCEPTS: The cars they could have made. This month a car that actually went into production! #BMW-Z4-Concept Coupe / #BMW-Z4-E86-Concept from #2005 is one BMW concept that did see the showroom floor / #BMW-Z4-E86 / #BMW-E86 / #BMW-E86-Concept /
One of the best-kept secrets and one of the biggest stars of the #2005-Frankfurt-Motor-Show was the Z4 Coupé. BMW usually wheels out a concept vehicle at its home show, but unlike many of its predecessors the ‘Concept’ Z4 Coupé was virtually production ready and even the Chairman of the Board, Dr Helmut Panke, admitted that a production version would be built.
When the Z4 was launched back in 2003 BMW claimed there would not be a Coupé version of the car to take over from the quirkily-styled Z3 tin-top. Despite claims to the contrary from the company the Z4 hadn’t been a universal success and the sexy hardtop Z4 was necessary to breathe much-needed life back into the range.
The ‘Concept’ was based on the Z4’s chassis and used the lightweight 2996cc ‘six that offered up 265hp at 6650rpm and 232lb ft of torque from 2500-4000rpm. BMW claimed performance figures of 5.7 seconds for the 0-62mph dash and a top speed limited to 155mph.
The Z4 Coupé’s styling was obviously heavily based on the Roadster, although its new ‘fastback’ look gave the car a much a more dynamic form. To our eyes the new model of Z4 looked more cohesive than the Roadster thanks to the higher rear deck afforded by the coupé design and it gave it a much more powerful look about its rear haunches.
There was a trademark Hofmeister kick to the C-pillar, while the centre recess on the roof itself harked back to coupé designs of the 1950s and 1960s. The Concept Z4’s lines were shown off to best effect by the Glacier silver matt paint effect which looked particularly dynamic under the show lights. To contrast with the bodywork it sat on bespoke chrome shadow 8x19-inch aluminium rims equipped with 235/35 ZR19 (front) and 255/35 ZR19 (rear) Michelin Pilot Sport Cup tyres, while the show car also sported the big drilled discs fitted to the then current M cars, although in the studio pictures the car made do with standard BMW stoppers.
Inside it was a mixture of Z4 Roadster and some new materials – such as the woven look for the leather door panels – and while we didn’t expect these to make the production version we hoped in vain that the roof lining would remain the soft Nubuk leather that was featured on the show car.
The luggage space was of a decent size thanks to the kicked-up rear deck and, as seemed to be the way back then, the press pack informed you of its dimensions in terms of golf clubs. In case you were wondering, you’d be able to fit two large golf bags in the boot, although whether that was with the natty integrated travel bags in place was not reported. #BMW had always said it would never build a coupé version of the Z4 and also that there would never be an M version either – but when the car it wasn’t going to build looked this good, and went as well as it did we’re jolly glad it changed its mind!Stream item published successfully. Item will now be visible on your stream.
- Post is under moderation10 MINUTE GUIDE E86 Z4 3.0si
The Z4 Coupé still looks fresh and purposeful and while M versions look set to rise in price the ‘lesser’ 3.0si still looks like excellent value for money. Words: Bob Harper / Photography: #BMW / #2006
Why should you buy one?
Whisper it quietly but we actually preferred the 3.0si to the manic M Coupé when these cars were new – certainly if you were planning to use the car everyday the 3.0si was the better prospect. And there’s loads to like: sexy styling, excellent performance (sub six-seconds to 62mph) from its sonorous straight-six and that’s blended with surprisingly good economy and affordable running costs. The cockpit is a little snug and there’s not a huge amount of storage space, but if that’s not a worrying issue you should get searching for one now.
Launched in 2006 the #BMW-Z4-3.0si-Coupé came in one flavour, so choosing a used example is straightforward. It came with the six-speed manual with a Sport auto as an option. Standard equipment was generous, with 17-inch alloys, electronically assisted Servotronic steering, a Sport button, front and side driver and passenger airbags, DSC+, run-flat tyres, electric mirrors, front fogs, headlight washers, metallic paint, auto air-con, brushed aluminium interior trim, one-touch electric windows, Oregon leather seats and a single CD player covered within its £31,400 price. A Sport model was also available at launch, adding 18-inch double-spoke alloys, anthracite headlining, M Sport seats, M Sport suspension and a three-spoke M leather steering wheel, costing £32,925. Options included the aforementioned automatic transmission, multi-function steering wheel controls, folding exterior mirrors, many different alloy wheels, auto-dimming mirrors, carbon leather trim, rear PDC, xenons, cruise, Business or Professional nav, Bluetooth, Logic7 speaker system, Comfort package and Nappa leather.
How much to pay?
The cheapest car we found was just under £5000. Admittedly it had done over 200k miles but it had been with the same owner since 2008. At the other end of the scale, 3.0sis still occasionally crop up at main dealers and these cars can be priced up to around £15k which we’d reckon is too much to pay given you can still bag a Z4 M Coupé for that sort of money. Choose the middle ground and you should be able to find a low(ish) mileage example that’s been well looked after for less than £10k.
What goes wrong?
We are happy to report that the short answer to this question is not a lot. Generally speaking the N52 straight-six that’s used in the Z4 Coupé is a pretty reliable unit and even as mileages rise it seems to have very few issues.
They don’t tend to use much oil and just about the only thing the engine is known for is a bit of a ticking from the top end which comes from the hydraulic valve actuators. BMW tried several fixes over the years with mixed success, but the noise doesn’t seem to affect the reliability of the unit. Running problems are most likely to be down to dodgy coils, but as this unit is pre-direct injection you’re far less likely to have any injector faults compared to some later units.
A few suspension components are a little less durable than you might like – rear springs in particular fail like clockwork but aren’t expensive and rear shock mounts can collapse. The front control arms are similar in design to the E46 so these can fail over time too. It should feel tight and clonk-free on the road, so get it checked if you’re at all unsure. Inside, check the steering doesn’t feel like it’s sticking at all – most likely to rear its ugly head in hot weather – as the only surefire fix is a new steering column assembly. If the car has sat nav then check the fold-out screen works smoothly as failed units need to be replaced. Also listen out for rattles on a road test – the Z4’s cockpit wasn’t especially well put together and you may find it can be a little creaky, and while it’s irritating, most problems can be sorted if you don’t mind putting the effort in.
Road tax costs £159.50 for six months and £290 for 12 – pretty decent for a 3.0-litre sports coupé and servicing shouldn’t cost the earth either. BMW’s value service menu quotes £189 for an oil service and microfilter, £269 for an Inspection 1, £429 for an Inspection 2 and £62 for a brake fluid change. New brake pads can be had from a main dealer for £129 or £119 front and rear respectively. Specialists may be able to beat these prices, but the bottom line is that the 3.0si doesn’t have the ‘M Tax’ that you get when it comes to sourcing parts for the more powerful Z4 M.
As standard the 3.0si came with run-flat tyres, but we’d recommend binning them as it transforms the way the car rides and handles. For an SE on 17s you should be able to get a set of good boots fitted for about £300 and for the Sport on 18s that will rise to around £450.
With a relatively low purchase price, sexy styling and reasonable running costs we love the Z4 3.0si Coupé. It’s refined and composed when you’re out for a cruise yet can lift up its skirts and fly when the mood takes you. As a used buy it’s an absolute cracker.
TECHNICAL DATA #BMW-E86 Z4 3.0si / #BMW-Z4-3.0si-E86 / #BMW-Z4-E86 / #BMW-Z4 /
ENGINE: Straight-six, 24-valve
MAX POWER: 265hp @ 6600rpm
MAX TORQUE: 232lb ft @ 2750rpm
TOP SPEED: 155mph (electronically limited)
0-62MPH: 5.7 seconds (6.0)
ECONOMY: 31.7mph (31.4)
EMISSIONS: (CO2): 213g/km (216)
PRICE: SE £31,400; Sport £32,925
Figures in brackets for automatic transmissionStream item published successfully. Item will now be visible on your stream.