The first test session at Jerez last week threw up some major surprises and interesting talking points, including the failure of Renault and the innovative aerodynamics on the McLaren.
Here JA on F1 technical adviser Mark Gillan, former chief operations engineer at Williams and Toyota explains how the F1 teams approach the pre-season tests and analyses what they will be doing now, back at base, to get ready for the next test in Bahrain.
What the F1 teams were aiming to achieve at the Jerez test
The 2014 energy recovery system (ERS) boosted F1 cars are extremely complex systems so it was undoubtedly with a lot of trepidation that the Teams and engine suppliers turned up at Jerez for the first test. Clearly Mercedes and Ferrari power units have had a good start to the season having proven to be generally reliable, allowing their associated Teams to do pretty good mileage, whereas Renault have had a difficult V6 turbo era inception, leaving their Teams with limited running.
One typically wants to complete a minimum of 1200kms and ideally over 1600kms on a 4 day test. The first test generally has the least mileage as you get to grips with the new car and complex systems, which normally require a little debugging. However by the second test you want to be doing high fuel long runs, typically of 15 to 20 lap stints to get an understanding of the car’s general behaviour and tyre usage. By the third test the whole test matrix should be finished with a full race simulation successfully completed.
Looking at the mileage completed at Jerez only Mercedes (1368kms) , Ferrari (1111kms) and McLaren (1084kms) will probably be happy. Williams, Sauber and Force India managed 774km, 721kms and 646kms respectively which is less than ideal, but still OK for a first test. However Caterham, Toro Rosso, Marussia and Red Bull only completed 336kms, 239kms, 132kms and 92kms respectively which means that very few of their test matrix items will have been ticked off.
Before the start of the season each Team will have created a complex test plan, listing a large number of test items to be accomplished. This list will include a prioritised set of important systems checks such as fuel run out tests (i.e. checking the ability of the car to pick up the last millilitres of fuel and to carefully study the collector pressure as the fuel runs out), to reliability checks which need mileage, to process checks such as race start simulations and pit-stops, to performance items, such as understanding the new car’s aeromap and general handling and tyre usage characteristics. It is imperative that each Team completes as much of this test programme as possible; this clearly needs the car and general team operations to be reliable.
Renault’s troubles not down to a single issue
Renault’s Rob White confirmed at the test that he was confident that they will get on top of the issues that had proved problematic throughout the test and which had limited their associated Teams running.
When one gets problems on a car it is rarely a single issue, and more normally a collection of problems which are interrelated and need fixed in an efficient and rigorous manner. With the complexity of the new V6 engine, larger battery pack, new power electronics, bigger MGU-K, new turbo and innovative MGU-H one should not underestimate the difficulty of this task. It also looks like Red Bull are having to rethink their cooling strategy as a result of certain components getting excessively hot. [Editor’s Note: MGU-K is the motor generator unit – kinetic i.e. the KERS motor (enlarged from last year) and MGU-H is the all new motor generator unit – Heat and is the electric motor associated with the new turbo and tasked with recovering heat from the exhaust.]
Do the lap times tell us anything about who looks quick?
With regards to analysing lap-times this is ‘fraught with danger’ even during a standard test but with this test effectively acting as an extended shake-down for the new power units one should not read too much into them. Having said that the McLaren and Williams do look to be a relative ‘step up’ from last season and the Ferrari looks pretty strong too, along with the Mercedes. We’ll get a much better feel for relative pace in Bahrain.
Eye catching innovations on the F1 cars
Every year something excites the F1 engineers about someone else’s design and this year was no different with McLaren’s rear suspension aero profiled geometry (above) , which acts probably as a pseudo split rear lower beam to energise the diffuser and upper rear wing cluster (the lower beam has disappeared in the 2014 regulations), causing a stir. The Teams will have got as many high definition pictures of this feature as possible, checked the regulations (and with the FIA), and then will test this feature in the next few days (if not already done so), to see what benefits, if any, it can bring to their car.
McLaren were also sporting a nice 32 channel automatic traverse Kiel Probe rake for measuring the pressure field aft of the front tyre. This test equipment will traverse vertically during a run (in quais-steady state conditions) to capture the complete wake off the front tyre for correlation with wind tunnel and computational fluid dynamics (CFD) data – this is crucial to make sure that the development process is working efficiently. (Note: With front wings 150mm narrower this year, moving the air cleanly around the front tyre is more difficult)
These probes are used in conjunction with standard flow viz paint (see Williams rear wing above) to ensure that the tunnel and CFD are correlating. For instance you can see the unwanted loss around central separator region on the Caterham’s rear wing upper cluster (i.e. the v shape on the flow viz).
What the F1 teams will be doing now ahead of the next test (Bahrain 19-22 February)
The Teams will now be ‘flat out’ analysing their own data and reacting to any issues encountered in the test and also analysing pictures of their competitors. The Power Unit suppliers will be doing the same, with Renault clearly having to react to what happened during the 4 days testing.
The issue for Renault will be repeating the problem on the dyno/bench – if they can do that then they will have a mechanism to fix the issue, if not, then the fix will be significantly more difficult.
From a personal perspective I have the greatest respect for both Rob White (Deputy Managing Director (Engine)) and Remi Taffin (Head of Track Operations) who are both extremely intelligent and tenacious engineers and whom will no doubt be back at base directing their staff and ensuring that the problems receive the appropriate attention