BMW M3 E92 and BMW M6 F13 – tuned by South African gurus RG Motorsport

Double Trouble A brace of M cars – an E92 M3 and a F13 M6 – tuned by South African gurus RG Motorsport.

M the post powerful letter in the world, raised to the formula of Rob Green Motorsport, gives you the most potent BMW conversions south of the Sahara. Over the last couple of years, we have mainly drawn our attention to modern day classic BMWs in South Africa. Which is a rather skewed observation of the BMW landscape… there is a diverse BMW following, in most cases bordering on fanaticism, with a burgeoning custom and tuning culture. So let’s broaden our horizons and look at two of the fi nest BMW conversions that have left the RGM stable.

Jacques Joubert, Brand Ambassador for RGM sums up the GTRS3S (S for Supercharged); “It was built to showcase RGM as the leading BMW tuner in Southern Africa, it has become the perfect BMW mascot for RGM. Back in 2010, no one went to this extreme to tune an E92 M3.” For Matt Braune the M6 was his dream car, as he puts it; “I decided to get the most modern high-end Sports car from BMW, which is the M6.” But Matt wanted something more, as he explains; “I gave Rob Green a challenge, I said, ‘Rob, I know that you guys are good, but I want the fastest M6 on the road, will you take me up on the challenge?’”

Rob Green cut his teeth in the motor industry as an apprentice at Stuart Bromfield BMW, in 1986. The BMW ethos, and the continuous strive for perfection, to produce driver-focused cars, left a lasting impression on Rob – who developed a strong penchant for the marque. In 1992 together with his brother Steven, they launched RGM, initially focusing its attention on BMWs. Realising the potential and demand from enthusiasts outside of the blue and white roundel, they started offering tuning solutions for a wide variety of automotive brands.

Today RGM offers a diverse tuning, modification and customisation service, using some of the leading performance brands to achieve outstanding results. Components such as exhaust systems, air-intakes, charge coolers and heat exchangers are designed (using CAD), developed and tested internally, using materials such as carbon fibre, aluminium and titanium. Over the past twenty five years, RGM has become one of the most prominent and recognised brands on the tuning scene in SA.

As the sun breaks over the horizon, it reflects a glow over the two Ms lined up in formation on the N1 highway, scampering off into the distance, towards our location, leaving behind a cacophony, piercing the early morning silence. It is a sight to behold… who needs Gran Turismo? Let’s turn our attention then to the orange M3, there is so much to take in, where to start. I know what you are thinking, why is it the same colour as the E92 M3 GTS? Coincidence is all it is, RGM’s colours happen to be orange, black and white and it is defi nitely not trying to mimic the GTS. The colour is just about all they have in common. Here are some stats to put it into perspective, the GTRS3S pushes out 761hp versus 450hp produced by the GTS, and 502lb ft of torque versus 325lb ft for the GTS. It will sprint from 0-62mph in 4.1 seconds, compared to the 4.4 seconds it takes the GTS. It tops out at 208mph, whereas the GTS can only manage 191mph.

The GTRS3S started off as a ‘plain Jane’ 2008 M3, dressed in silver. At the time (2010) RGM became the sole distributor for Vorsteiner in Southern Africa, and needed a draw-card. The M3 seemed the perfect match to show off the Vorsteiner product, and refl ect what RGM is capable of. It was unveiled at the Top Gear Festival in 2010, one of the biggest motoring extravaganzas in South Africa. At the festival it was aptly baptised the ‘Thing’ (Marvel comic Superhero), by an ardent RGM fan/follower. The Vorsteiner GTRS3 carbon fi bre kit is what gives it its monstrous appearance: the kit adds 60mm on either side in the front and 140mm on either side at the rear… ginormous. Eight perfectly sculpted carbon fi bre pieces make up the kit, comprising side skirts, front fenders, bonnet, front bumper (with a more pronounced air-dam and front splitter), rear arches which were bonded into the body, boot-lid with spoiler (reminiscent of the M3 CSL), and rear bumper, incorporating a diff user.

Rather large wheels were needed to fill those enormous arches, again Vorsteiner offers the perfect solution in the form of the V-308, which is a three piece 20-inch wheel, made from aerospace, T6-6061 forged aluminium. The front wheels measure 9.5-inches in width, and rears 12.5-inches, fitted with equally large boots, Michelin Pilot Sport II, 285/25 R20 in the front, and 325/25 R20 at the rear. To offset the orange and match the other black accents on the car, RGM finished off the wheels with a satin black centre and high gloss outer ring. Glowing behind the wheels are colour coded, Brembo callipers, from the ultra high performance Gran Turismo range, 380mm vented and cross-drilled discs in the front, with six piston callipers, four piston callipers at the rear with 380mm discs.

The aero bits on the M3 make a bold statement, but at the very heart of this conversion, is the Vortech V2 SI-trim centrifugal supercharger. It produces mechanical boost pressure of 0.5 bar (6psi). But before it is fed into the engine, the air is forced into a charge cooler, the water in the cooler is cooled by heat exchangers positioned behind the central air intake, with two water reservoirs feeding the cooler, positioned behind the left and right air intakes. The supercharger itself is fed with pressurised oil for lubrication and cooling, through a gravitational oil return system to the engine sump.

All rather technical, but goes to the very essence of what makes this beast tick. All the ancillaries, which included the carbon fibre air intake, charge cooler, heat exchangers, water reservoirs, pulleys and piping are developed internally. To manage all this additional power more effectively, a Unichip has been installed. Keeping the ‘Thing’ planted to the asphalt are KW Variant 3 coilovers, fully adjustable, which means the load and rebound can be regulated and the ride height can be lowered by up to 15mm.

And so to Matt’s M6 Coupé. I am eager to find out what makes a man, after owning one of the most accomplished GT Saloons for two years decide that it needs something more… wouldn’t an M6 Competition Package have been enough? “I wanted to differentiate my M6 from the rest, in South Africa and maybe even in the world,” commented Matt.  “Fifteen years ago I owned an E36328i and asked RGM to extract a little more power, and to beef up the exhaust note. To me Rob and the RGM team are very professional, the quality of their workmanship is excellent, that is why I had confidence in them, to do what needed to be done to the M6.”

I can’t argue with the finished product! It looks great in Sakhir orange and those lines of the subtle engine scoop (with matching vents), accentuates the creases on the carbon fibre bonnet (by Prior- Design) perfectly, making it look more muscular. The black stripes down the shoulder-line match the wheels, kidney grilles, carbon boot spoiler and rear diffuser which have been finished in satin black, creating a sportier look that is not over the top.

The H&R lowering kit, gives it just the right amount of aggression, with a 34mm drop in the front and 20mm at the rear. The standard brake callipers have been retained, but fitted with racing pads and Vari ventilated and slotted discs have been fitted, 400mm in the front and 396mm at the rear, to ensure the right amount of stopping power. Central to the conversion again are the mechanicals, RGM upgraded all the internals of the turbo chargers, but kept the original housings. A bespoke downpipe using Techniflow components was installed, which links to the Akrapovic exhaust system – devoid of cats throughout. To extrude the maximum power, a plug-and-play Unichip was installed, which allows for five map settings from within the cockpit. The result is staggering, 925hp (680kW) and 804lb ft (1090Nm). Matt however explains that it did not happen overnight: “It was RGM’s first time tuning a F13 M6. We did not get to the current level of performance the first time. We had to find a way to control the boost pressure, in gears one to three, otherwise the car would just spin uncontrollably.

The exhaust needed some fine tuning and we had to play around with the fuel mix – we added a fuel additive, Torque race fuel, which boosts performance. In all it took about a year and a half, which included vigorous testing, on and off the dyno.” But is Matt happy with the result? “Ecstatic!” he says with a broad grin across his face. “In August last year at the ODI Raceway, we achieved a speed of 275.5km/h (171mph), over one kilometre from a standing start, making it the fastest M6 in South Africa at the time. We were the car to beat on the day, on the rolling start we completely annihilated the competition, no one could come close. With regulating the boost pressure in the first three gears, meant I had no traction problems, so I could just put my foot down.” It goes well on track too, as Matt recounts; “I achieved a 2:09 at the Kyalami circuit, at the BMW Car Club track day, on road tyres. Only a GTR in my class could beat the M6, doing a 2:08, not bad considering it has four-wheel drive.”

Time to find out, how all that this power equates to performance on the road. First up is the ‘Thing’, and as I approach I notice that there is a just a sliver of space between the rubber and the wide arches. Jacques explains that the KW coil-overs are set to the stiffest setting, to prevent the wheels from slamming into the arches, when going over uneven terrain.

In for a rough ride then? Inside the cockpit is pretty much what you’d expect from an M3, except for the RGM motif found on the headrests in orange stitching. Once in the driver’s seat you are pleasantly surprised to find the nifty BMW Performance steering wheel, with the shift indicator, oil and water temperatures, lap timer, G-force meter, etc. Engage the ignition and the engine explodes into life, barking in anger through a custom catless Techniflow exhaust. The ‘Thing’ retains the standard manual gearbox and clutch, gear inputs are thus light and easy. Beware of the throttle though, measured inputs are required even on pull away, too much and the tail snaps out. With 20-inch wheels and a tyre profile equal to that of a racing bicycle, and absolutely no give in the suspension, means you feel every crease in the road. Bury your foot on the throttle, on an open stretch of road and you can feel the immense power pinning you into your seat, while your ears are being pounded with an incessant roar. The pull created by the supercharger is relentless, demanding the 8000rpm red-line, all the while the shift indicator flashing in your line of sight. And when you realise that you have run out of road and step on the anchors, instinctively your grip around the steering tightens, flexing the muscles in your forearms, pushing you back into your seat. The ‘Thing’ is an absolute hooligan, with so much power, finding yourself going sideways and breaking the speed limit is par-for-the-course.

The cabin of the M6 is a fantastic place to be, lush and superbly finished. BMW has made a marked recovery from the somewhat shoddy interior of the previous generation, and has returned to the drivercentric cockpit layout. I like the touch button door closure, which Matt chose as an optional extra. Press the start button, and you immediately notice that the exhaust note has more of a rasp to it. You can hear the sound reverberating all the way from the engine through the Akrapovic piping and out the back…   marvellous. The exhaust is fitted with a flap control module, allowing valves in the exhaust to open or close at the push of a button. Allowing you to be suave and sophisticated…or loud and obnoxious. To put the M6 through its paces we find a closed section of track. Floor the throttle and tug the gear paddle, the rear jolts to the right, nose veering to the left, feed through some opposite lock to prevent contact with the raised pavement.

This action is repeated all the way into fourth gear, clearly not all the shenanigans from the turbos have been dialled out of the first couple of gears. Soon enough we are approaching warp speed and with the limiter having been disengaged, you just put your foot down and see how fast you can go – we reach an indicated 300km/h (186mph) before backing off. Inside the M6 there is a calmness that detaches one from this frenetic speed, while all focus falls on the head-up display.

And so for the verdict, the ‘Thing’ is a whiteknuckle ride that is not for the feint-at- heart. It is much better suited for the track and drag strip, a complete spectacle if you will, yet the perfect marketing tool, to show off the capabilities of RGM. I much prefer the M6, ludicrously quick but with the opulence and comfort that only a BMW flagship can afford you. I’ll let Matt sum it up in his own words: “I am very happy, as it is still a complete road-going M6 with all the comforts, yet with Supercar performance. I drive it daily if I want to, and on the race track when the opportunity arises. In all honesty I prefer top end runs, as it is a heavy car, but very good in a straight line, as it manages to get all the power down.”


CONTACT RG Motorsport


Bury your foot on the throttle on an open stretch of road and you can feel the immense power pinning you into your seat. The Akrapovic exhaust contains no cats and sounds absolutely glorious at full chat; Below: The engine might look standard but features heavily revised turbos to gain power.


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