"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).
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.
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.
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 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.
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.
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!
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.
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.
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...