ADDING THE ‘R’

Noise. Lots of noise. That’s the first difference you notice when stepping from the HS to the HSR. With a pair of exotic Dell’Orto carburettors having replaced the HS’s much milder Strombergs (a £350 option in period), this is a truly fantasticsounding engine, adding growls, pops and bangs to the muscle car-like burble found in the HS. Thanks to the increased induction roar, conversation is almost impossible in the HSR at high revs.

Added in to the mix is a cacophony of rattles, mostly emanating from that glassfibre tailgate. This is initially an intimidating experience, particularly for those who would commonly spend time patting down pieces of trim in a bid to find the source of unwelcome vibrations in their classics. After a few minutes, however, you accept that this is how the car is, and that it’s just a part of its rallycar-for-the-road character.

It’s not noise for noise’s sake, because the HSR gains roughly 15bhp over the HS. It would be hyperbole to say that this is revolutionary, but the extra tuning helps the engine to climb through the revs more eagerly.

This is a good thing, not just because that extra power is to be found high up the rev range, but because the extra tuning creates flat spots lower down. There’s still plenty of torque there, but you need to keep the revs high to keep the carbs on song. Otherwise, it simply feels like the HS turned up to 11, with even sharper steering thanks to the reduced weight and – given our car’s lowered suspension – firmer handling.

It’s less flexible than the HS, and the ride is more easily disturbed by bumps, but it’s eye-wateringly dirty fun when you put the hammer down.