A WORD of advice for Audi is in order: don't even mention the masterful Ur-Quattro in reference to the TT RS because the Deutsche duo are nothing alike.

All sensory indicators come up with negative as far as a meaningful DNA connection is concerned, since sight, touch, feel, smell and (especially) taste don’t tally up at all between the two.

And we should know, having lived with a used and abused 10V import for a big chunk of 1988.

One was an anti-fashion pioneer built in Germany featuring a 50:50 permanent drive Torsen diff, monumental turbo lag followed by thrilling thrust and a brown furry cabin of comical austerity – and the other is a designer front-driver from Hungary leveraging a Haldex clutch to create an AWD slingshot of explosive response, a gorgeous cabin, incomparable safety and lots of luxury.

Even the latest Beetle seems more closely related to its humble predecessor.

Now that’s out of the way, the TT RS can scoot out of the Ur-Quattro’s shadow and be judged on its own merit.

This is an interesting vehicle technically and it’s odd that Audi is deliberately a little vague on the “new” 2.5-litre in-line five-cylinder petrol engine’s origins.

Why? It appears that this 250kW/450Nm 2480cc powerplant is a much-modified VW unit employed in the US Golf and Jetta and perhaps even the Transporter van. And the latter has reportedly donated its six-speed manual gearbox to the RS as well.

Not very Ingolstadt then, but – surprise, surprise – this TT actually keeps in the spirit of the Quattro since that car raided the 1970s VW Iltis military vehicle-based 4WD running gear parts bin. So the van connections are quite apt really. Good one, Audi.

And although the rest of the package is pure TT – and that’s also a good thing, because we are very enthusiastic about this 70:30 aluminium/steel coupe with a Golf front end, special multi-link rear, and taut overall proportions – it is the big turbo five-pot VW drivetrain that is the heart and soul of the RS.

It lives up to the sporting sub-brand’s heritage too, joining the ranks of the 1990s five-cylinder turbo RS2 Avant (another Audi 80-based machine), as well as the RS4 and RS6 jetliners from the last 10 years.

Fire it up and the 2.5L’s rorty noise is quite alluring, if not in-you-face, but the moment you depress the meaty clutch and slot that heavy-ish gear lever into first, you know plenty of muscle is ready to be flexed.

Open the taps and speed is suddenly all around you, as the Audi sprints forward without hesitation or fear.

There’s plenty of action and tractability in every one of those six gears, so you don’t really need to give yourself the workout of rowing the RS along, but the noise is pretty fabulous.

Then we pressed the ‘S’ button in the lower console area and the car’s mood darkened considerably, with a more guttural exhaust resonance and a harder throttle response to match the altered suspension setting – which goes from firm but pliable (thanks to the excellent standard Magnetic Ride Control technology) to aching on some surfaces.

But the trade-off is tighter, quicker steering, combined with superb roadholding. The RS follows the road like a bloodhound, sniffing out bends, powering its way around them with intense speed and agility, and having the confidence of control afforded by the recalibrated ESC system and larger four-wheel ventilated brake package that’s also part of the top TT’s repertoire.

At this point the Porsche Cayman springs to mind, since the Audi’s $133,700 plus on-roads inhabits the empty space between the sweet base model and the 911-troubling S.

In fact, the TT RS is a very different animal, despite seeming so similar in so many ways, swapping the finesse, tactility and pliancy of the supernaturally talented Porsche for a brute force that isn’t immediately obvious if you’re just pottering around town, but is there to be exploited should the fancy take you.

Speaking of fancy, the TT’s cabin continues to be a real source of strength for this car too, from its RS bucket seats to the hewed from solid, err, whatever of the beautifully executed dashboard.

We’re not fans of the garish exterior trim though, which detracts from the more basic TT models’ design purity.

But we’re smitten with the way the RS feels and drives.

This makes for an appealingly raw alternative to the Cayman, as well as a bolshie rival to the suave and sophisticated Z4 sDrive35i.

You can also feel the family connection between this car and the last RS4, arguably the greatest RS in the company’s family tree.

So while Audi has not conjured up another game-changer, the RS should easily bend you perception of what the TT is.

What it ain’t is a Quattro.