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Ireland's asphalt is unique - on no other WRC round of the 2007 calendar are drivers and teams faced with such a combination of bumps, narrow roads, a heady mix of gravel and the likelihood of rain.

But what does this actually mean for the way the Subaru World Rally Team prepares for the event? Operations director Paul Howarth explains some of the intricacies of this fledgling WRC round.

"Most noticeable is the way in which the setup of the cars differs from what would be considered a normal sealed surface event" says Paul. Half way between gravel and tarmac, the Imprezas display the typical 18" BBS wheels and low profile BFGoodrich g-Force Profiler tyres, but run a higher ride height and softer suspension settings more akin to that used on gravel. This combination helps to maximise grip whilst stabilising the car over the uneven surface, which changes with every kilometre.

"When the roads are so narrow and often wet, stability and driver confidence in the car is essential" he continues. "From a driver's perspective, Rally Ireland is one where you just cannot make any mistakes, as the likelihood of them being costly is high. There is no room for error as the grass verges lining the roads become very slippery and unforgiving. With many tight switchbacks and stages of up to 27km in length, concentration and precise lines are crucial.

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"The high chance of rain and the fact that the roads take a long time to dry mean that the Imprezas have a baseline setup for the wet". This includes ride height, roll bar stiffness and spring and damper rates, and also suits the interspersed gravel sections better than would a dry asphalt setup. "Such a setup would give away time if the stages were totally dry, but the whole approach to Rally Ireland requires finding the right balance, and a dry setup in the wet would potentially lose far more time over the course of a stage.

"One of the major engineering challenges that Rally Ireland presents is getting temperature into the tyres on the stages, and keeping it there. As the roads are so narrow, there is only one line for most of the route and so the tyres don't work as hard as on a traditional asphalt event. As they are not working as hard, they won't generate as much heat". That they don't hold much residual heat means the sudden and tight switchbacks onto narrow tracks can prove very tricky to judge for grip.

As a result tyre wear is low, so the team can opt for a softer BFGoodrich tyre, which works better at low temperatures than harder variants are able to but will still last the distance.

Rally Ireland and unique are words that are often twinned, and it is very true of the setup the event demands. So tailored to the conditions, it is not used on any other event of the year, and unless visiting Ireland to test, conditions are very hard to exactly replicate elsewhere.