When the Formula One teams arrive in Germany this weekend they will face a completely different shorter and slower Hockenheim circuit. But despite the new layout, they will not step into unknown territory thanks to the highly sophisticated computer simulations. Atlas F1's Will Gray talked to Renault's Pat Symonds, and the Briton explained the challenges of preparing to race at the new track

All 22 drivers on the Grand Prix grid will get their first taste of the newly designed Hockenheim circuit on Friday and although they have already been there before with the circuit in a previous guise, they should already feel like they have driven the new track before even if they haven't seen it for themselves.

The modern times allow teams to use simulation packages to define a set-up of a car even if the track is not even built so, for instance, an engineer could tell, to a reasonable accuracy, how fast their car could go around the circuit designs in Bahrain and Cairo - if they wanted to do so.

Such information would not be particularly useful right now, but to know how quick they can go around the new 4.574km circuit at Hockenheim, which has been totally changed since it was last raced on in July last year, will be very handy.

The long straights on which cars used to speed through the dense woodland have been removed for the sake of spectators, allowing the German circuit to double capacity for this year's event. They have been replaced by more corners and a long curved straight at the rear of the circuit, which leads into a tight hairpin corner.

Renault engineering boss Pat Symonds predicts that a lap of the new Hockenheim circuit will take around one minute and 18.2 seconds in a car that regularly competes at the front end of the grid, and he knows that because of his complex computer wizardry that has allowed Renault to drive the circuit already.

Symonds is very thankful for the simulation, because the changes to the circuit have had a knock-on effect on the unchanged section to make Hockenheim, he says, effectively a brand new track altogether. And that means it is even more of a challenge to understand what set-up to run for this weekend's race.

"The way we start any preparation for any race is with simulations," said Symonds. "But for Hockenheim we are really dealing with a totally new circuit. They have only modified part of it, but in our terms it's completely new and that is because in the past we used to run very low drag and low downforce there, which meant we were driving a car that had far too little downforce on it for the type of corners you had in the stadium.

"This year the compromise moves to a higher level of downforce an therefore the stadium will seem like a completely new circuit as well and it is probably best illustrated in turn 12, which is the turn into the stadium.

"Last year, we would be approaching that corner at around 330 km/h, absolutely flat out, and we would have to take that corner at around 180 km/h. This year, because we come out of the new section we will be arriving at just under 280 km/h but taking the corner at 220 km/h because we have more downforce on the car.

"I think the drivers are going to find it quite strange. A corner that they think they know well, they are going to be arriving at it an awful lot slower and going around it an awful lot quicker, so they mustn't approach the race thinking they know the circuit.

"Similarly as you approach turn 13, the Sachs Curve, you are arriving there much faster than last year because you have come out of the previous turn a lot faster, so it is really a totally new circuit and we rely on our computer simulation more than ever."

That simulation basically consists of combining coordinates from surveyor's maps and plugging the positions into a computer that can then work out all the forces on the car as it travels around the imaginary lap. The detailed track lap can also be used to run the teams' research and development rigs.

These effectively consist of a car sat on a number of hydraulic posts, which move in sequence with the movements predicted at the track while other hydraulic rams pull down on the car to simulate the predicted aerodynamic downforce. That allows teams to create a general set-up for the car's suspension to perfect mechanical grip, but there are certain areas in which the team will enter this weekend's race blind.

"The simulations do not tell us the complete story and there are still lots of things we don't know about the circuit - for instance what is the tarmac like. We do know the whole circuit has been resurfaced but we don't know whether it is a grippy sort of asphalt or a smooth and slippery sort of asphalt.

"We don't know anything about the bumps on the circuit because if a circuit is re-surfaced, even parts of the circuit that we know, sometimes that resurfacing can amplify the bumps and sometimes it can smooth them. We have no knowledge of that. Equally the kerbs, we don't have that level of detail on our maps."

In the past, a new track has been designated an extra practice day, on the Thursday, to allow teams to work out their set-ups and to 'bed' the track in after its creation. And although the new Hockenheim is, effectively, a new track, that luxury will not be granted and the team will be paying particular attention to precise aspects of the racetrack on foot.

"On Thursday we will be walking around the circuit with the drivers," said Symonds. "We will be looking at the kerbs, we will be maybe modifying our set-ups a bit based on that and, of course, after we have first run on Friday, when we have got some more relevant data, we will be re-doing all our simulations and updating the set-up.

"For race strategy, we can calculate quite accurately the effect of carrying fuel but we really have absolutely no knowledge of tyre degradation so all we can do, because we have to start somewhere, is look at the characteristics of the circuit and at the point we started doing this work we didn't know what tyres we are taking there.

"So we assume an average tyre degradation for that type of circuit and that leads us into what we think the strategy will be and therefore our approach to the whole weekend in terms of what sort of fuel loads we will run and what we need to look at."