My Monaco technical review is now on Automoto365.com. with all the details of he developments from the weekend; Redbulls blown rear wing, Virgins updates, Ferraris winglet and other details from up and down the pitlane
At the start of the Monaco Race, McLaren had a rare engine failure. This was not a problem with the engine itself, but caused by a procedural problem on the grid.
Before setting off for the grid the car is warmed up in the garage and the driver often completes several laps, cutting through the pit lane before finally parking on the grid. By this time the car is fully up to temperature and needs fans to keep the car cool. In the case of the engines radiators and oil coolers, this takes the form of fans inserted into the sidepod inlets. Fans pass cooling air through the radiator cores to cool the engines fluids.
For McLaren their sidepod fans comprise several parts, an external fan which feeds into convoluted tubing to a carbon fibre duct, this has the option of a tray of frozen nitrogen being inserted into it to further reduce temperatures. This then is inserted into a rigid foam block that is squeezed tightly into the sidepod inlet itself. Other teams have electrical fans fitted into similar carbon mouldings, these are all in one piece and when removed nothing can be left behind.
What happened to McLaren in Monaco, and this was partly shown by the FIA TV feed, that the mechanics withdrew the ducts and tubing, but on one side the foam black was left stuffed in the sidepod inlet. This was obviously missed by the mechanics, but was brought to their attention by the BBC TV pit lane reporter Ted Kravitz. By then it was too late and the car had to complete the formation lap and start the race with the block still in. The team were obviously anxious, but the block does have a hole through it, so some cooling airflow was getting through. With the safety car deployed on the opening lap and the pit lane closed, Button had no choice but to circulate a low speed, with the engines temperature slowly rising until steam could be seen spewing from the sidepod.
Although this was a rare error, as the car has these fans fitted when it pits during testing and free practice. One still wonders if McLaren will revert to a one piece design or tighten up the grid procedure to prevent another similar situation arising at future races.
So while wheelbase is not a primary factor in rounding tight turns, then what is? Steering lock accounts for most of the solution, only Loews at Monaco (the tightest turn in F1) and La Source are turns where the driver has to turn the wheel beyond half a lock. Drivers sometimes having to remove one hand from the wheel, to get enough clearance for their crossed arms. If the front wheels can turn enough then the car will get around a tight turn, of course a longer wheelbase car will need slightly more lock for the same turn a short wheelbase car. To allow the front wheels to steer enough a few mechanical alterations are required. Firstly the steering racks can be altered with a different ratio to the rack and pinion. But more commonly the outboard end of the track rod is brought closer to the uprights kingpin (steering) axis, resulting in more ‘steer’ for the same rack displacement. This can bring an extra 5-degrees of steering angle. To allow a power steering system to have a longer stroke, the teams need to alter the pistons that assist the rack in moving, by also making them longer. Then at the outboard end of the wishbone, the pivot bearing should have enough freedom to steer the wheel through the required angle, but clearance between the wheel and the wishbone often requires the wishbones to be altered. This is normally just a notch moulded in the rear leg of the upper wishbone. Teams do also fit more robust wishbones for brushing the Armco, as well as tougher drive shafts. Although the latter is as much about accelerating over bumpy surfaces, than the side thrust from a wheel touching the barrier.
So who ever goes well at this weekends GP, will be as a result of a mechanical set up and downforce that are matched to the tyres. How long their wheelbase is not going to be the deciding factor. Although who actually wins may be as much down to luck as any set up parameter!