PH contributor David Vivian dropped into Sumo Power GT HQ recently, where as well as an update on progress for the team's FIA GT1 campaign, he got wind of a special Nissan GT-R road car being cooked-up by the boss. Well you would, wouldn't you?
Last Christmas, JRM Group boss and sometime drag-racer James Rumsey caught wind of a rumour that the Gigawave Motorsport team was shutting up shop and wouldn't be representing Nissan in the 2010 FIA GT1 championship with its Nismo-developed V8-engined, rear-drive GTR. He was off the mark faster than his personal, modified roadgoing GTR with launch control engaged. A smoky blur of phone calls and contact connections later, the deal was all but wrapped up in the finest Yuletide paper with a pretty bow on top and the Sumo Power GT team was born.
Nice pressie and something for his burgeoning Japanese car tuning and motorsport business to get its teeth into at its shiny new premises in Rye, East Sussex - not least the awesome SuperFlow SF-902 dyno that lives in the Engine Room.
Just a month ago it was all going to plan - slightly better, in fact. Boosted by a win at Silverstone in May, Sumo Power GT was lying second in the team contest and 4th and 5th in the driver standings. This was obviously very good going for a brand new team up with a car effectively denied the turbocharging, four-wheel drive and electronic hardware that help make it such a formidable force on the road. After all, it's competing in a cost-conscious, back-to-basics formula (where power and weight are carefully balanced for closer racing) that naturally favours many of its more traditional supercar rivals such as the Ford GT, Aston Martin DB9, Chevrolet Corvette and (perhaps unsurprisingly leading the championship) Maserati MC 12.
After an incident packed race at Spa where they were denied a podium finish by a driveline failure within a lap and a half of the chequered flag, the Sumo Power GT team has slipped to third in the team but there's everything still to play for...
The upgrade path for James Rumsey's roadgoing GTR - known, rather prosaically, as "the R35 demonstrator" - started with the standard HKS GT600 upgrade kit which, among other things, boosts power from the standard car's 478bhp to a nice round 600. But rather than stick with the HKS ECU, Rumsey opted for the Cobb access port system which enabled him to map the car on JRM's rolling road while keeping a lot of the safety features that the standard ECU employs intact (plus the overboost facility). And that liberated another 100bhp with no trouble at all.
So, 700 horsepower. "The problem with that sort of power (and it's well documented)," JRM marketing manager Alan Zini told me, "is that the gearboxes tend to fail. There's an issue with 1st gear when launch control is enabled. Our solution is a PPG complete gear set - we're a UK agent - which, right now, is sitting downstairs.
The gearbox is in pieces and we're about to rebuild the 'box using the PPG gear kit. The other thing we want to do is put a completely new set of bearings in there, and that's been really problematic because it seems as though Nissan doesn't want to supply individual gearbox components. So what we've done is have all the bearings reverse engineered in Australia. The gearbox is going to back together with the PPG kit and new bearings. The car will then go on to its next stage, which is probably going to be an 800 or 900 horsepower upgrade.
JRM also has six standard R35 engines which are being stripped to see where the weak links are and what sort of upgrades might be suitable. Zini: "We've got five of those gear kits sitting on the shelf and the idea is that we'll actually build complete gearboxes, PPG kit and uprated bearings installed, ready to go. The plan is that customers shouldn't encounter those same problems. Drive in, pay the money, drive out with a new gearbox, no problems at all. And the reworked gearbox should be good for 1000 plus horsepower without breaking. Fact is, the cars have got the capability to do that sort of power."
On top of that, Rumsey's GTR will have uprated, two-piece discs on the front, a lowering kit that uses the standard springs and dampers but repositioned mounts to drop the body by 20mm and Toyo track day tyres on 20-inch rims. Never mind Godzilla, let's call this one The Terminator. And when it's ready, I'll be back.
Race photos by Darren Rycroft
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