Feature Article: first printed in FasTForward, 2007
Words: Rob Bell,
"At SP we have really, really done it! We've gone and built the WORLD'S FIRST SUPERCHARGED MGF - THE CHEETAH!! It's the car that every driver dreams about." And so they had. This was the first line on SP Performance's web-site, extolling the release of the superlative SP Cheetah. SP Performance - a subsidiary of Stephen Palmer Garages of Long Eaton, Nottingham had realised something quite extraordinary - a daring and risky plan: to build a truly high performance MGF, under a new sub-brand called "Cheetah".
By the time of the Cheetah's launch, at the January Autosport show in 1998, Stephen Palmer had become one of the most successful MG dealerships in the country. It seems unlikely that Mr Palmer and his team would have become so successful had they not been attentive to their customers' needs and responsive to their comments. Listening to their customers' lead the team at Stephen Palmer to realise that there was a thus far unrealised need in the market for products that complemented and accentuated the strengths of the basic MGF product - and consequently, it wasn't long before SP Performance was born. Clearly, the SP sales people kept hearing the same story from their customers - the standard car sounds too quiet, and needs more of a sports car sound. SP themselves had no experience in fabrication, so instead they looked for collaborations with other companies with the skills required to fulfil their design brief. With regard to the disappointingly refined standard exhaust note (for a sports car!), they went knocking on the door of Milltek - a well regarded after-market exhaust manufacturer.
Milltek did them proud - producing, in high quality stainless steel, the SP "Super Sports" exhaust system, with large bore, upswept "DTM" Style tail pipe finishers. Forget about the aesthetics - the system simply sounded sublime. Refined enough at motorway pace, on acceleration, the exhaust system simply wailed in a wonderfully tuneful and enthusiastic manner. In 1998, Performance Car (the tome that a certain young Jeremy Clarkson wrote a rather entertaining column for - long before he became famous on the BBC) wrote enthusiastically of this exhaust: "every MGF should have one!!!" Clearly, hundreds of customers thought so too - and now the SP Supersport is one of the most successful exhaust systems ever marketed for the MGF.
SP Performance didn't stop there either - they went on to sell replacement filters, and a whole range of other performance and aesthetic goodies - all of which went on to be strong sellers.
SP Performance felt they knew the market. And some of their customers were telling them that these bolt-on goodies were all very well, but how about some serious performance? That was a tough one - but SP felt that they could make the dream of a higher performance MGF happen - something that would cement SP as one of the premier suppliers of high performance MGs. And SP had learnt through their experience with collaborations with Milltek et al that they could work with third parties to help realise new product ideas, and turn them into profit-earning sales for the parent business. Perhaps they were looking enviously at the German tuning houses? We may never know, but a series of events were triggered, events that would culminate in a new SP Performance product that would shock the fledgling MGF community - the launch of the astonishing SP Cheetah.
Project Cheetah - the Objectives
is clearly more than one way to extract power from an engine, but from the
outset SP Performance were seeking for a substantial power gain, yet they wanted
the car to remain tractable and easy to drive and easy to service by maintaining
compatibility with Rover's "Testbook" diagnostic hardware. This immediately
ruled out a conventional, normally aspirated, tuned engine with its peaky power
delivery and need for alternative an engine control unit (which would not be
diagnostic compliant and represent an integration problem with the standard fit
alarm and immobiliser). Forced induction could be an option - so SP got on the
telephone to talk with one of the UK's best known Turbo specialists -
Turbo Technics of Northampton.
However, Turbo-charging has two disadvantages. One is throttle response - catch
a turbo "off boost", the car will feel sluggish, before the power returns in a
punch to the kidneys proportional to the state of tune. A good turbo
installation can largely ameliorate this lag, but there is no doubting that a
turbo will never have the sharp responses of a normally aspirated engine. The
other disadvantage is even more critical for the MGF. Heat. A turbocharger gets
extremely hot, and under bonnet temperatures soar as a consequence. This becomes
a real problem when the engine, like that in the MGF, is in an enclosed steel
box in the middle of the car with little airflow to vent the excess heat. But
Turbo Technics had an answer: a hybrid modified turbocharger with a specially
adapted gearbox driven from the crankshaft pulley mated together to create a
centrifugal compressor - the Rotrex Supercharger (pictured right). With instant
induction boost from any engine speed, and potentially much cooler engine bay
temperatures over the turbocharger alternative, this was clearly a winner for
the MGF package - and this is how SP decided to specify their Cheetah. With an
additional ECU to control an additional pair of fuel injectors to cover the
engine's increased appetite for air and fuel, the conversion retained the car's
standard ECU. This was great news: so all the standard anti-theft equipment
remains operational and untouched, and the car could continue to be serviced by
any Rover service agent.
The bad news was cost: the Turbo Technics kit added a cool £5000+ to the price of a new MGF. Would buyers be prepared to pay that much for a car that looked standard? This lead SP to talk with Krafthaus - a Midlands-based styling house with a history of successful projects for companies such as Bentley and Jaguar. Krafthaus stylists worked hard to produce a stylish and distinctive bolt-on styling kit, with wheel arch extensions and a generally more muscular and aggressive stance on the road. It would be difficult to deny that they were successful in this aim. Now the problem was that the standard 15" wheels looked somewhat puny under those exaggerated wheel arches. No problem: SP specified a set of AZEV 17" alloy wheels which subtly increased the track of the car, filling out the arches, and completing the Cheetah's unique appearance.
The look was almost there. But no self-respecting car tuner can avoid putting some badges on the car - and SP were no different. But SP did go one step further than most - they specified a new set of instruments featuring, incredibly, a pair of glowing 'Cheetah eyes' on the green-faced rev-counter! It certainly represents a surprising and unique feature of a full-works SP Performance MGF.
With the look and the performance practically sorted, what of the chassis and the brakes? Here, the changes were surprisingly modest. Standard (240mm) brake discs were retained, albeit specified from Rover Sport and Racing, and these were coupled with Mintex brake pads - offering greater resistance to fade compared with the standard faire. As these were the same rotors used on the MG Maestro Turbo, perhaps it was felt that these brakes would be adequate for the Cheetah? There was no sign of 4-pot calipers or monster sized brake discs that might otherwise be expected on a vehicle of this kind of performance potential. On the chassis front, the shock-absorbers remained standard, but the hydragas spheres were changed for the Cheetah - using the competition units specified for the French MGF Race series - and thus offered stiffer springing and firmer damping. And other than a few other minor details, this is how the SP Cheetah was finally specified.
Into the melting pot…
With so many
choice components on a single car, you'd expect the whole to be the
extra-ordinary product of the sum of all its parts wouldn't you? And in some
ways, the car didn't disappoint. You certainly couldn't argue with the
performance: the VVC version of the car (you could also buy a supercharged
1.8Mpi version for a small 25bhp performance penalty) provided an astonishing
215 bhp and 185 lb.ft torque, both peaking near 6000rpm. Despite the high rpm
torque peak, the engine is a good deal less peaky that the numbers would
suggest, with meaty stump-pulling torque evident throughout the rev-range. This
muscular performance provided the MGF with a 0-60 time of 5.5 seconds (nearly
2.5 seconds faster than the standard car), a 0-100 of 12.9 seconds and a top
speed that was artificially limited to a staggering 150mph!
The styling? Well, the instrument pack wasn't to everyone's taste, but you didn't need to buy that, and the same applied for the body kit and wheels - but there is no denying that the car looked the part. In the right colour, this was one menacing beast with the near super-car performance that the SP Performance web-site rightly boasted.
On the road the car wasn't bad either - with magazines being broadly approving of the cars manners. Sure the ride was harder than standard - but then what do you expect with huge 17" rims and liquorice-thin rubber wrapped around them? The car provided safe, sure-footed fun - and was a terrific point and squirt machine.
But out and out adulation escaped the Cheetah - and one doesn't have to look too far to find out why. The complete Cheetah package would set you back a cool £29,500 in 1998… and because of the position of the supercharger, there was no air-conditioning. The sticker price set expectations to a level where the Cheetah's humble MGF origins simply could not support. The interior, which served the basic £17,000 roadster so well, looked, well, cheap for a £30,000 motor car. There was a lack of the aforementioned air-conditioning (arguably less of a liability then than it is in today's market), and somehow, the underpinnings appeared somewhat under-engineered (although whether this was the reality is open to debate).
The Rocky Road…
So now SP Performance had a very audacious and ambitious product to sell. Unfortunately, unlike the bolt-on items that SP had sold successfully, the Cheetah propelled them into a market that the sales team were perhaps a little unfamiliar with. It is unclear as to exactly how many SP Cheetahs were built in their full body-kitted and Cheetah-badged glory - but rumours were that only five were built to the full specification. Customers who were put off by the styling could purchase the engine modifications alone - and a number more cars were either sold or converted after sale in this way - the Supercharger installation alone costing an eye-watering £5600. And so, for the next two years, SP Performance continued to work hard to sell their unique creation. At the many shows that the company attended, there is no doubt that the car gained considerable attention - but again and again, cost was the primary barrier to greater sales. It seemed that there was a threshold at which MG buyers were prepared to spend for or on the MGF - and £30,000 comfortably exceeded that limit. Perhaps the Cheetah's sales failure may have played a part in spelling the end to MG's own Supercharged MGF - the Supersports, the concept of which was first seen at Geneva 1998 - a car that was also expected to cost in the region of £30,000… Lucky for MG then that SP Performance performed their market research for them.
Despite the SP dealership continuing to be a great success, with standard MGFs flying out of the showroom, and the SP Performance range of exhausts and other accessories doing well, SP were heading into troubled waters. Before long, Stephen Palmer had lost its Rover franchise. The reasons for this remain unclear - the official line from SP was that Rover had demanded that SP invest heavily in new showroom facilities - an investment that Mr Palmer was not prepared - or could not afford - to make. But this line did not stop many from proposing an alternative conspiracy theory. Perhaps management at BMW/Rover Group were unhappy about one of their dealers modifying their cars so blatantly. Perhaps they were unhappy that SP had managed to bring their Supercharged MGF to the market before MG could even bring their own concept to a motor show. Perhaps Stephen Palmer Ltd didn't fall. Perhaps they were pushed…
Unfortunately, the loss of the Rover franchise effectively spelled the end of SP Performance and the Cheetah. Stephen Palmer Garages went on to take up a TVR franchise, but sadly the company went to the wall within a year or so of the end of MGF sales from their Long Eaton premises. A sad end to both Stephen Palmer Ltd and to SP Performance.
Fortunately, the SP legacy lives on: you can still purchase the SP/ Milltek Supersports and related GT exhausts from MGF specialists, Brown and Gammons - along with the front aerodynamic splitter, that was pioneered on the Cheetah's body kit. The body kit moulds also remain in existence, now owned by British Motor Heritage following the collapse of Krafthaus (whose demise was unrelated to the collapse of SP). Even the supercharger conversion remains available as Turbo Technics themselves continue from strength to strength; the Supercharger kit was an unexpected hit amongst Lotus Elise owners. Consequently, the supercharger installation has undergone much development over the years, becoming more reliable and even more powerful in the process (270-300 bhp anyone?) and remains available for installation on the MGF and TF.
And what of the Cheetah? These are undeniably rare cars and represent a unique slice of MGF history. The Cheetah has another legacy too - a lesson to any would be owner of the MG marque that an MG roadster needs to be affordable and accessible for it to be a success…
The original SP Performance press release, circa September 1998:
we have really, really done it! We've gone and built the WORLD'S FIRST
SUPERCHARGED MGF - THE CHEETAH!!
It's the car that every driver dreams about. It has:
The world famous automotive designer's KRAFTHAUS have restyled and enhanced the curvaceous MGF, revealing an aggressive, lower and wider stance. Masculine! Poised for Action!
200 bhp is produced by the forced induction Rotrex Supercharger developed specifically for the CHEETAH by Turbo Technics. Check out the Cheetah's Full Specification
SP Performance exhaust system that sounds great and
provides a 12% power increase @ 5,000rpm, over the standard mild steel
Price £29,500 inc VAT. - The Affordable Supercar!
The GT SP Performance exhaust system, a further addition to the range to complement the popular Super Sport, has been developed to meet the needs of our more conservative MGF enthusiasts. This is, undoubtedly, for the driver that prefers a slightly more refined exhaust note, but still wants to stand out from the crowd with a piece of engineering that looks stunning.
The enormously popular Super Sport exhaust, offers you the ultimate race bred system for the road. A truly evocative sound with the phenomenal power gains and the stamp of Milltek Sport, quality engineering.
EXTRA PERFORMANCE COMPONENTS:
Autosport Show, January 1998
Above: the SP MGF Hardtop, more recently described as the "Heritage Hardtop" - they're one and the same.
Top Gear's 1998 appraisal of the SP Performance Cheetah