"My car is better than yours as it won the 2006 BTCC championship" is the sort of debating point you often see wheeled out in the PH forums. (Only if your car happens to be a Honda Integra, surely?! - Riggers).
OK, you can substitute the race series of your choice, though that is the essence of the argument. But is it really valid to compare a racing car to the one you drive around in on a day-to-day basis? Having spotted the RJN Motorsport version of my own 370Z set one of the fastest times of the day at the Goodwood Festival of Speed - where I was lucky enough to take a 370Z Roadster up the famous hill - I thought that it was time to find out for myself.
It seems as though much of British motorsport is run from converted farm buildings across the country, and RJN's workshop is no different. Down a country lane north of Wantage, the RJN team prepare and develop the GT4 and Dunlop Sports Maxx Cup versions of my Nissan 370Z.
I'm greeted by RJN owner Bob Neville with a cup of tea, and they show me around the Cup car. The 370Z Dunlop Sports Maxx Cup racer was originally developedfor the Playstation GT Academy and is the closest model to the road going Zed I turned up in.
So do they just grab a shell off the assembly line to make this car? "You could do it from a bodyshell and it would save you a lot of metal preparation, because you haven't got all the sealants and sound deadening to remove," says Bob. "But even if you do it from the shell, you want the car anyway, because you need so much of it. You want the windscreen, the door handles, the door skins, the aluminium doors, the wings, the engine..." OK, I get the picture.
The dash and centre console are all standard, and the wiring loom still runs around the car like an exposed artery. The electric glass windows and door mirrors are still in place. The pedal box is the same and, from the driver's seat, everything seems familiar. Even a number plate for the car hangs nearby, ready to be popped on for a bit of road testing.
Underneath the car, the RJN Motorsport team have been doing a little tweaking. After they have stripped out the internals and fitted a roll cage, race seat and racing steering wheel they get to work on the handling. The coil springs are uprated, the brake material changed, the fluid upgraded and cooling ducts for the discs are added.
The really major work happens on the subframe, which is re-drilled and welded to give the car a fixed three degrees of negative camber and a little toe-in to scrub some heat into the rear tyres. The viscous differential is replaced by a more durable limited-slip plate differential so it can cope with the whole race season, though the standard drive-shafts are left in; they have yet to break one.
The engine stays standard and there are no funny settings on the ECU - though a bit of fuse trickery is used to turn the traction control completely off whilst not fooling the engine management system. The gearbox is also the standard 6-speed from the road car, with the synchro rev feature disabled.
"The car has a strange valve arrangement in the engine," says Bob. "It has an electric motor, which changes the inlet cam, completely different to a normal variable valve system. With this particular engine, the oil temperature gets a bit warmish when you are pushing, so we developed a cooling kit that's been approved by the Nissan Technical Centre."
You can get one of your own for around £830 - possibly a worthwhile investment if you want to rack up plenty of track time in your Zed.
The other bit of development work the guys at RJN did for the 370Z was with Janspeed on a new exhaust system. This gives an extra 12bhp by allowing the car to breathe better and, as a lovely by-product, brings out the true sound of the V6 engine (we reckon the standard car sounds a bit strained).
I did suggest leaving the PH Nissan 370Z with RJN so they could convert the car to the Dunlop Sports Maxx Cup specifications, especially as it all remains road legal. Bob was more than willing to oblige, but a cheque for £35k to £40k was required to seal the deal and they'd have needed the car for 10 days with two guys working flat out. Shame!
As we walk over to the GT4 car I ask Bob if the process was the same for creating a more hardcore machine such as this. "The process is the same, but it will be just over double the price of the Cup car to have everything done to make it GT4."
This car is a more extreme step up than with the Sport Maxx car. The windows are thrown away and replaced by polycarbonate, Nismo spoilers and wings are added around the car and the removing of internals is far more extreme - right down to removing the skins and materials from inside the chassis.
The engine is shipped in from Japan and a Quaife gearbox is inserted into the car. The suspension and brakes are uprated and air jacks are added to allow quick pit stops - though only three are used to save weight. But certain components have to stay with the car if fitted on the road version, so the ABS remains.
The car was being prepared for the team's seventh attempt at a 24-hour race at the time I visited, so there was a 100-litre fuel tank being added. Other than that, the components on the car don't change for the 24-hour races and the same engine is used as for the 40-minute sprint races. Even the brake pads are only changed once.
There's an old 350Z in the corner - the one used at Goodwood - and I ask Bob how similar the cars are. "The only similarities between the two cars are the rear differential and the Quaife gearbox in the GT4. The wheelbase, track, even the design of the uprights are all different and in effect it is just like developing a completely new car.
"For the 350Z we had to get Hewland to develop new drive-shafts as we were breaking lots, but the 370Z standard ones haven't caused any problems. Another major difference is the sub-frame; the 350 has a beautiful alloy one and a customer saw it recently on the side and asked where we made that. I had to tell him it was standard on his car, though the 370Z is now steel."
The guys (and Bob's wife) at RJN Motorsport know their Zeds pretty well and it is fair to say more parts of the road car appear on the race cars than I first suspected. Which does mean that, at the next race meeting where a 370Z beats a race version of your car on track, my road car will be officially faster than yours...
![](data:image/svg+xml,%3Csvg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 4 3"%3E%3C/svg%3E)
![](data:image/svg+xml,%3Csvg xmlns="https://www.w3.org/2000/svg" viewBox="0 0 1 1"%3E%3C/svg%3E)