CARRERA CUP CAKE
There’s nothing like being on a race track with a proper racing car, and when that happens to be a front-running Carrera Cup 964 it’s a fabulous bonus.
Welcome to the tea party! This time we have a really amazing piece of car confectionary to drool over. We’ve come to Abbeville circuit in the Picardy region of northern France at the invitation of our Belgian friend Johan Dirickx. A prolific 911RS enthusiast, he’s recently acquired the 964 Carrera Cup Car that Harald Gröhs drove to 2nd place in the 1994 Championship, and Johan’s keen to demonstrate its capabilities around this twisty 13-bend racetrack. Being a 964 fan I’m doubly excited as it’ll be my first on-track outing in an out-and-out Carrera Cup race car. Sure, I’ve tracked the Peppermint Pig, but that’s merely lowered and stiffened (by Carrera Cup winners Roock Racing, let it be said), and I’ve driven Hartwig Rietz’s one-off 964 Tiptronic Cup Car (that Walter Röhrl raced at the Nürburgring) on the road. A couple of N-GTs as well, the rawest incarnation of the 964RS. Just never a 964 racer on a track.
First, a bit of backgroundto the 964 Carrera Cup car. Introduced in 1990 to replace the 944 Turbo Cup models, fifty 964s designated for the Carrera Cup series were pulled off the Zuffenhausen production line and handed over to Roland Kussmaul and Jürgen Barth at the Weissach competition department, where the shells were stripped of every roadgoing nicety including carpet and sound deadening in preparation for their competition role. Output from the blueprinted 3.6-litre M64/03 flat-six was initially 265bhp (195kW) at 6,100rpm, red-lined at 6,800rpm, rising to 275bhp in 1993. The blower fan was dropped and the aluminium induction chamber replaced by a plastic version, saving 1.2kg in the bid to eliminate extraneous items in the quest for lightness.
The five-speed G50 gearbox has shortened ratios installed for 3rd, 4th and 5th gears, plus limited-slip diff. Suspension comprises harder, shorter springs, adjustable Bilstein twin-tube dampers and anti-roll bars, with ride-height set 55mm lower than standard. The detailing includes tiny Carrera Cup door windows, next to useless compared with ‘teardrops’ or elephant’s ears’ though no doubt bestowing a degree of aerodynamic efficiency. There’s an external cut-off switch on the scuttle, plus another one under the bonnet. Also to the right of the scuttle there’s another external plug-in for the air bottle that mechanics deploy to jack the car up in pit stops. The first run of cars were fitted with bolt-in aluminium roll cages, superseded in 1992 with a comprehensively welded-in Matter steel cage, which is what we have here.
From 1986 the Carrera Cup race was the curtain-raiser at F1 Grands Prix, opening the door to international and national Carrera Cup championships and, from 1994, the Super Cup series. The 50 original 964 Cup cars were joined in 1991 by 120 more, as national championships blossomed, then another 112 in ’92, and an additional 15 cars in ’93. Cup cars built during 1990 and 1991 were based on 964 C2 shells and thus carry relevant production numbers, and 1992 and 1993 Cup cars were built on European RS shells. Our Abbeville car is chassis No WPOZZZ96ZPS498004, engine number 62P80503. It was delivered to Obermaier Racing in June 1993, and is one of the last batch of 15 cars. The 964 was then superseded by the 993. The cars were sold to private teams and customers, initially to run in the eponymous race series in Germany and France, and subsequently in dedicated national series worldwide. A 100,000DM bond was required from buyers to deter profiteers from cashing in, returnable after the cars had done six races.
As well as Carrera Cup stalwarts like Uwe Alzen, Altfrid Heger, Roland Asch and Olaf Manthey, star drivers such as Walter Röhrl, Hans Stuck, Jacques Lafitte and Jochen Mass also guested at the helm of 964 Cup Cars. The main claim to fame for Johan’s car is that Harald Gröhs drove it to 2nd place in the 1994 German Carrera Cup. A veteran Porsche and BMW racer from the ’70s, teamed with the likes of Stucky and Ronnie Peterson, Gröhs’s track record during the 964 Cup Car era includes 2nd place in two 24-hour races at the Nürburgring and Spa in 1991, a similar accolade in ’92, and in the second half of ’93 and ’94 he campaigned this 964 in the national Carrera Cup, finishing ’93 in 6th place in the Carrera Cup, having scored a win at the Salzburgring. He also ran in the Porsche Supercup with a 3.8-engined 964 and the ADAC GT Cup that year, placing 5th in the GT Cup and 7th in the Supercup. ‘I was the busiest racer in Germany that season,’ he recalls, having logged 19 starts in total. The best was yet to come: he finished 2nd in the 1994 German Carrera Cup, with wins at Zolder, Nürburgring and Hockenheim. Late in the ’94 season another name appears on the car’s Wagenpass, Tessa Schmidt, who had an entry at the Nürburgring, and then Hockenheim, Monza and Spa in 1995. Also that year, Harald Gröhs won the title with a 993 Cup Car.
‘There are a couple more cars that which were in the same livery as this one,’ Johan points out, ‘because Gröhs also drove a 964 3.8 in the German GT series, but this was the actual car which he came 2nd in the Carrera Cup in ’93 behind Bernd Maylander and ahead of Wolfgang Land who was a previous Carrera Cup champion.’ Here is Harald Gröhs’ take on the car, interviewed at my behestby Hartwig Rietz who owns the unique 964 Tiptronic Cup car. ‘The 964 Cup car was very, very reliable,’ says Harald, ‘especially the engine and gearbox, which never caused any problems. The Cup car was so good that we used it with a bigger tank for endurance racing and it was still reliable. It wasn´t easy to drive at the limit; a wet track made it really tricky - the rear end wasn´t easy to control. I drove all the 911s from 1973 until today, so I really know what I´m talking about. The Cup car had to be managed (brakes and tyres, that is) over the whole race distance, because with worn tyres at the end of the race it was hard to keep the rear end in line. A soft and "round" driving style helped a lot to preserve the tyres, so that they didn’t overheat. In general the Pirelli tyres were absolutely ok.’
According to Harald, set-up was crucial: ‘it was very important to have an absolutely precise set-up, camber, toe-in, etc. I had my car set up with a little tendency to understeer - the rear tyres were preserved this way and I was fully competitive at the end of the race. This varied a bit from track to track, of course. If one of the lesswell-known drivers won a race or was on the podium that meant that the hotshoes had ruined their tyres and brakes before the chequered flag.’
Inevitably, competition was tough. ‘In the Carrera Cup it was real close racing on a high level, and Porsche controlled the cars very well - the engine ECU was supplied by Porsche, gear ratios were the same for everyone everywhere. No modifications were allowed and that was strictly controlled. Porsche did a good job there.As I was really late and hard on the brakes, I made sure that discs and pads were brand new for every race, and despite that, sometimes the brakes were gone before the end of the race. I really killed my brakes! The top guys absolutely had to watch their brakes and tyres to make sure they would make it to the end of the race. There were no tactics; from the moment the lights went green it was close and brutal in-fighting. One eye was permanently in the rear view mirror! The 964 was very solid; it could stand some pushing and shoving, and so we did. My main rivals were Olaf Manthey, Wolfgang Land (who knew every trick in the book!), Danny Pfeil (if he had a good day), Frank Schmickler, Klaus Graf (who learnt how to drive these special cars very quickly), Altfrid Heger, Uwe Alzen and, last but not least, Horst Farnbacher.’
Harald has fond memories of the newer Carrera models too. ‘Among all the Cup cars I drove, the new ones with paddle-shift and water-cooled engines are real fine race cars, fast and easy to drive. They guarantee close racing with a grid of about forty cars. The fact that they are relatively easy to drive gives those drivers who are not absolutely on top level, a good chance to be competitive and so we see some good racing. But my heart beats faster for the air-cooled Cup cars, the 964 and 993.Later on Tessa Schmidt drove that 964 in Porsche Clubsport; she raced it for one season.’ So, now we know.
In the late-’90s the now ex-Gröhs 964 was sold to a US enthusiast who campaigned it in Porsche Club North America events. Ownership subsequently passed to Pat DiGiovanni who raced it to 2nd place in the Speedvision series, 1st place in the GrandAm Motorola Cup and was SCCA regional champion. He then restored it, and it won first prize in the racing car concours in the 2012 Porsche parade, leading to an outright Concours d’Elegance win in Denver in 2013. That’s when Johan came into the picture and made him an offer he couldn’t refuse.
And it’s great for us that he did, because we can now give it a twirl on track. The 964 Carrera Cup car bears many of the hallmarks of its road-going siblings, but as befits a racecar, it’s a totally raw experience on track, and, surprise, surprise, it is noticeably quicker than a normal 964. I dare say that you could get an N-GT to lap just as quickly as the spec is virtually identical, and maybe a 964 RS would stay with it. All I know is this seems swifter even than the 4WD C4 Leichtbau we sampled a few years ago on this very circuit; there’s less roll for one thing, and no less grip despite being just rear-wheel drive.
Johan agrees; there is a big difference between a proper 964 Cup Car and an RS: ‘the chassis set-up is stiffer, it’s obviously more track-orientated, the suspension has less bounce and re-bounce, the chassis is very well set-up, it’s taut because of the welded-in roll cage, turn-in is good, so hitting the apex is easy. It’s got a lot of power, so you come out of the turn and there’s instant delivery when you come on the throttle, but it is very manageable. You can accelerate while coming out of the turn and power-slide so you still gain speed instead of losing speed. Basically, it is a fabulous little car!’
Having just emerged from a ragging session in his 964 3.8 RSR, Johan is amazed that the Carrera Cup car performs so well by comparison. ‘I thought it would be a drag compared to the 3.8 RSR, which is a race car after all, and this is a very, very nice car.’ Johan, who’s raced at Laguna Seca with his 993 RSR and Carrera 3.0 ‘Dinkel Acker’ RS, and Classic Le Mans in the ex-Peterson/Nilsson 3.5 CSL ‘Batmobile’, fancies going racing with the 964 Cup car, and to prove the point he asks techie Mike van Dingenen to fit a set of slicks on the Cup rims instead of the 18in magnesium Speedline split-rims that it ran with in period. ‘I’m done with driving on these six-year old tyres,’ he laughs. ‘The front lacks a little bit of grip, and I locked up the brakes one time and flat-spotted the tyres, but it will be interesting to see how it goes with brand new slicks.’The Speedlines are fitted with Pirelli Corsa 265/645 x 18s on the back and 235/635 x 18s on the front. The Michelin-X radial slicks that it’s wearing on its magnesium Cup wheels are labelled (enigmatically, unless you’re a connoisseur) 20/61 x 17s on the front and 24/64 x 17 on the back, with the cautionary “for competition purposes only”, embossed on the tyre side-wall.
If Johan does go racing with it, he’d even consider taking it back to the States where unmodified Carrera Cup cars get a run. ‘Quite a lot of Cup Cars went to the US after they got pensioned off in Europe, because they could race competitively in PCMA events, something that they could not do anymore in Europe, so a number of cars are still being found in the US.’ He has more than enough experience with his various RSs and competition 911s to know whether one car delivers more speed or power than another, and is sure the 964 Cup must have more than 260bhp. ‘It feels quicker than the RS, and along the straight in 4th gear it goes up the power band all the way to almost 7,000rpm before I’m braking. I don’t have a clue about the speed, but it’s pretty fast and you feel it has enough torque to get out of the corners and drive it forwards, and that’s why I think it’s a better engine than the RS engine; I think it’s closer to 300bhp than 260bhp.
Racing cars are the epitome of austerity. The cabin interior is completely empty, except for a single seat and the roll cage. An absence of carpet, trim and soundproofing contributes to an all-up weight of 1100kg. The engine management box sits behind the driver’s seat in the rear footwell. The air-jacks are located in three different places on the floorpan, forming a triangle with the single jack in the front compartment where the spacesaver would normally sit. The two rearward jacks are mounted either side in the footwell behind the driver’s seat and where the passengers would be, along with the control boxes that operate them. Their function is to push the car off of the ground during a high-speed mid-race wheel and tyre change. There’s no automatic fire extinguisher system, just a manual appliance. Under the front lid there’s a very large strut brace between the shock turrets. The car has had some damage in its time – there are few self-respecting race cars that haven’t - and the front end has been rebuilt at least once with a whole new front clip. But it clearly goes very well and handles properly, so it can’t have been affected too badly.
911 Motorsports’s mechanic Mike van Dingenen is thoroughly familiar with the anatomy of 964s: ‘there is a real difference between the suspension set-up of the standard C2 and the Cup Car,’ he says; ‘different springs, dampers, anti-roll bars and settings.’ He shows me the Wagenpass which has some of the set-up numbers logged. The settings are staggered from one side of the car to the other: for example, for the Norisring race on 24th June ’94, everything from tyre pressures and corner weights to camber settings and toe adjustments are different on all four corners of the car, with yet more variations for a wet track. And there’d be different damper settings too. And as if that’s not enough, the numbers are different for every other circuit too. ‘Get your head around that, Johnny!’ he laughs. Quite so; these are the levels of sophistication employed at the top of the game. ‘The brakes are similar to those of a ’92 RS, although these are Pagid racing pads, and though the engine’s electronics are different, for the rest it’s mostly similar to an original 964 C2. Basically they’ve taken an original car and stripped off everything that you don’t need in order to race it. You can feel that the suspension makes a big, big difference between the original car and the Cup Car. The 964 Cup Car is much more like a street car than the 3.8 RSR, though; that is very different. Bearing in mind the evolution of the Cup Car and the fact that it was driven by pro drivers, I’m really lucky to be working on a car like this.’
Let’s get on track, then! Johan’s been out and warmed up the engine and those Michelin slicks. I don my Peltor helmet and Sparco gloves, and buckle up my Schroth four-point harness. I’ve even got my race boots on. It’s cosseting in the cockpit in spite of having just a single chair and few amenities. Though surrounded by cage the tubes aren’t intrusive. It smells of racing car, a concoction of warm oil, hot engine, ticking brakes and molten slicks. With no sound insulation and bare metal between cabin and engine bay all the mechanical noises from engine, ancillaries and transmission are prominent. My Peltor lid is fitted with an intercom headset so I’m largely oblivious to this cacophony once I’m up and running. The clutch is just as heavy as I expected it would be, and there’s a bit of a balancing act with clutch and throttle to get it moving.
The steering is beautifully light and direct, and the shift doesn’t baulk at all. Acceleration is swift out of the paddock apron, and I’m judging the weight of the unassisted steering and the grip of the slicks as I turn manfully into the first right-left, crossing arms and watching for the apexes while allowing the car to run wide for the dash to the next long, broad right-hander. The car goes from apex right over to the left, teetering on the edge of the tarmac, then I short shift and belt up to the infield’s flowing right-left, straightlining the curves on the way. These slicks are impressively sticky, the car absolutely compliant. Clearly I’m not going fast enough! I copy Johan’s line to the entry into the left-right kink, the tricksiest part of the circuit, debating whether I should be in 2nd or 3rd, then a broad sweep leftwards to the penultimate right-hand hairpin. Drop a cog, power it round, running far left on the exit for another spurt to the final 90 degree right-hander that most showboaters take sideways and on to the main straight again. I repeat this ten times, getting more and more familiar with the car with each lap. Since it’s red lined at 8,500rpm, I take it up to a modest 6,000rpm in each gear, and I note that 4,000rpm to 6,000rpm is the mean operating rev range. It’s fabulous to be driving a proper racing car, familiar to this 964 buff yet quite different: more solid, implacable, and unmovable.
Yet it’s so sympathetic, it’s a forgiving car that wants to do everything that you want to do. The strength of the engine is palpable, the power instantly on tap, and I can feel the strength and tautness of the chassis, undamped by roadgoing niceties. Those are the differences; everything is more basic, but everything is made to be more efficient, to be faster and more responsive. It’s very compliant, and feels like it wants you to have a good time. It gives you that little bit more than a N-GT RS. Combine the austerity and uncompromising ride of the Cup Car with normal creature comforts of a 964 C2 like my own set of wheels, and thatsure would be like having your cake and eating it.
