What’s it like to ride shotgun in Nissan’s 500bhp ‘GT500’ GT-R?

It began with an innocent promise. ‘We’ll give you a passenger lap in one of our GT cars,” they said. “It’ll be fun,” they said.

They – that’s Nismo – clearly read from a different dictionary, because hearing the bloody thing from a mile off, ‘fun’ is the last thing it sounds like. It sounds like Mount Fuji ready to erupt. It sounds… painful.

The GT car in question is Nismo’s R35 GT-R Super GT GT500 racer; a pared back, hunkered down, wide-arched agent of destruction with lots of GTs in its name, and a few titles too.

It took the 2011 and 2012 Japanese Super GT championships, and was brought out of hibernation for the annual end-of-year Nismo Festival in Japan.

Step forward, Fuji speedway; that glorious, old school track nestled in the foothills of Mount Fuji – or Fuji-san – as nobody says.

You know the one; immortalised through Hunt and Lauda’s epic 1976 Formula One title battle and the grandstand of many bleary-eyed, late night Gran Turismo sessions. It’s a marvel. It’s also bone dry, clear and ripe for Italian racer Ronnie Quintarelli.

Quintarelli, it turns out, is a triple Japanese Super GT champion, who happens to be proficient in (a) Japanese, and (b) scaring unsuspecting passengers senseless. TG is beckoned into the passenger seat. Game time.

So, comically oversized race suit on and heart pounding, I’m dumped into a racing seat far narrower than I am. The low, wide carbon fibre sill, narrow entry and multitude of switchgear in the large centre console make it near impossible to get in without looking like an idiot.

I hit a few switches as my hands fumble around for leverage. Ronnie isn’t impressed.

We shake hands, cordially – vice-like racer’s grip? Check – and wait for our turn to head out of the pit lane. A moment’s breath then, to understand what we’re sitting in.

This Super GT racer is the last of the V8 breed. Based loosely on the underpinnings of the current, R35 GT-R, it is shorn of its four-wheel-drive system, and over 500kg of road-things – things like the rear seats, air-con, insides, and other such guff. It’s basically a DTM car.

Out goes the road-car’s 3.8-litre, twin-turbo V6 too, and in its place sits a race-bred, 3.4-litre V8 producing around 500 horsepowers. Angry, loud and spiteful horspowers, it turns out. There’s a six-speed sequential gearbox with a 5.5-inch triple-plate carbon clutch, sending power to the rear wheels alone. It’s two metres wide, 4.7 metres long, weighs just 1,110kg (versus the road-going GT-R’s 1740kg), and sits on 330-section 18s up front, and 17s on the rear. Looks magnificent, too.

“Are you OK?” Ronnie asks. An unsure thumbs-up. We get our cue, and Quintarelli fires up the V8. Something has erupted, and it isn’t that mountain. Every fibre of the car – and my brain – pulsates with a raw energy; the sills, the seat, the chassis and rollcage, all of it feels as though it’s ripe to burst. It’s ear-splittingly loud. Honest, I thought I’d burst one of my ear canals.

He looks across, another thumbs up – this time questioning my resolve – and I foolishly tell him to go for it.

Bad move. My head hits the seat as all the throttle is applied. The GT500 pulls over 3g in corners, and accelerates like many swear words unfit for publication on a family website. The vista sweeps past. I clench my stomach to counter the forces acting against it, but it doesn’t work. It really hurts.

Quintarelli is bloody loving it though, the git. He’s good, too, nailing the GT500 perfectly through Fuji’s long, sweeping corners. Then the straight. He takes one hand off the steering wheel to get my attention and point at the digital speedo on the steering wheel.

There’s traffic up ahead – a few more 370Zs performing similar passenger duties – but he’s nailed on. 250km/h flashes past. Then 260. 270. 280.

We’re really going quickly now, and closing in on the Zs. We’re also about to sail past the braking boards. We could have hit over 300km/h – 186mph – but like I said, traffic and all.

Then some brakes happen. Those monster disks stop the GT500 on a penny, some more internal swearing occurs, and Quintarelli goes for one last, banzai lap.

I don’t feel the majesty of this championship-winning car, nor how stably and comfortably it sweeps through the 300R and Dunlop corners, nor the fact that it’s around 10 seconds a lap faster around Fuji than a full-blooded GT-R GT3 car.

The acceleration? Savage. Cornering prowess? G-force, it turns out, just plain hurts. The noise is physically uncomfortable, too. Thankful for relief after two laps, we come to a rest in the pitlane.

“It’s very stable,” Ronnie tells me, “just unbelievably good. We didn’t win in 2013, but still. It’s just really well sorted and very, very stable.” I shake hands, trade pleasantries, and fumble my way out and find somewhere to sit down.

If ever offered a ride in a GT500 racer, here’s my advice, kids: just say no. Astonishing machine to look at, race in and admire, really painful to take a ride in.