Analysis: Why are Mercedes off the pace in Singapore?

Disclaimer: I have very little data to draw my opinions on Mercedes’ strange lack of pace in Singapore, so take this with a big pinch of salt. The team do not understand the situation (yet), as said by Nico Rosberg in his post-qualifying interview. Therefore you can take whatever you want from this article, or even nothing at all. I thought I’d give my views on the situation because it’s interesting. It’s good for the sport that Mercedes are off the boil and it’s generating both excitement and discussion. So let’s discuss! Leave your thoughts in the comments.

Immediately after qualifying of the 2015 Singapore GP finished, I darted for a pen and paper and kept watching the Sky broadcast. I have taken notes from interviews and compiled a bit of data from the session to attempt to explain why Mercedes found themselves on the third row of the grid, 1.4s off Sebastian Vettel who was on pole.

In this post I am going to give my opinions as to why the Silver Arrows were so wide of the mark.

Tyre pressures

The first thing that springs to mind about just why the Silver Arrows were so far off is the recent tyre pressures debacle that has been raging on since Spa.

So let’s clarify what the minimum tyre pressures have been over the past few races:

Belgium: Front tyres – 18.5 psi; Rear tyres – 20 psi

Italy: Front tyres -19.5 psi; Rear tyres – 21 psi

Singapore: Front tyres – 18 psi; Rear tyres – 17 psi

Between Belgium and Italy the minimum pressure was raised by just 1 psi front and rear in the end, after a number of drivers were openly critical about the way Pirelli were handling Sebastian Vettel’s blowout in Spa.

In Singapore the minimum pressures are dropped anyway to suit the Marina Bay street circuit – with no high speed corners and plenty of traction zones, this makes sense. Pirelli have, however, increased their minimum pressures by 2 psi and 1 psi front and rear respectively over 2014, i.e. in Singapore last year they were minimum 16 psi front and rear.

Anything over half a psi can make a real difference to the car’s handling, so this change will have had an affect on the teams in this year’s Singapore GP as all their data used to pre-determine setup is based off substantially lower tyre pressures from 2014.

Having said this, Niki Lauda’s interview with Sky suggested that the new minimums had nothing to do with their performance. Of course we do not know if he is telling the truth, but he sounded sincere enough. If we are to take his word, we have to discount the latest tyre debate as a factor in why Mercedes were so poor.

Car characteristics

In 2014 Mercedes took pole position by just 0.173s over the next best car, which was Red Bull. It has become apparent during the hybrid era that Mercedes’ advantage is cut when they are on the Soft and Supersoft tyres. Whilst the field generally bunches together for street circuits, the others are altogether much closer to the Mercs than expected – even over a long lap such as the Marina Bay. This is a trait that Mercedes are well aware of and are yet to fully understand why this happens.

The W06 may be the class of the field, but there is still some slight mystery as to who really has the best chassis in F1. Teams have access to GPS data to assess cornering speeds, and it’s Mercedes and Red Bull who lead the way.

Mercedes are particularly strong in high speed corners as they have both good downforce and power behind them. Red Bull are especially good in mid/low-speed corners, and have been (arguably) since 2009 so they have always talked up their chances of taking the fight to the top teams at street circuits despite a weak power unit.

Mercedes are still good at low speed, just not quite there with the ‘Bulls. Good mechanical grip is essential, as well as consistent aerodynamics – a typical low speed corner is still taken at 50mph so managing that airflow is important.

Mercedes have gone down an intriguing path mechanically compared to their rivals. Their suspension always seems more supple and compliant, allowing the drivers to straddle (not necessarily ride over) the kerbs more aggressively without reducing the ability to put heat into the tyres. Stiffer suspension allows the tyre to generate heat as the car is not absorbing energy under load. However balancing the tyre pressures with suspension setup is a key factor in bringing the tyres into their optimal temperature window. More on this later.

It was rare to see the Mercs running their massive, multi-element Y100 (monkey seat) winglet above the exhaust for qualifying, despite not using it much on Friday. Even in Monaco the team didn’t use it. This suggests that they really were in search for some more rear downforce, as the winglet helps draw the exhaust plume towards the underside of the rear wing to keep airflow attached for longer.

Power units

I had a few of people tweet during the qualifying aftermath suggesting that Mercedes had turned down their power unit due to reliability reasons, but I believe this simply isn’t true.

To confirm, Rosberg had to switch to the old-specification power unit in Italy after FP3 because there was a water/coolant leak that contaminated the new one. This new unit has since been repaired, and will act as a Friday engine for the rest of the year with the one he is currently using in Singapore being used for the remaining qualifying sessions and races.

There is therefore no reason to suspect that Mercedes would reduce the performance output of their power units for this weekend as there have been no issues since.

So was Ferrari’s Italy PU update actually a big step forward? James Allison doesn’t think the latest token expenditure has to do with Mercedes’ downfall. Speaking to Ted Kravitz after qualifying, he said that 10hp is worth 0.1s in Singapore. So even if the Mercs had their units turned down, I very much doubt it would be to the tune of 140hp…

Onboard footage

Comparing footage from Lewis Hamilton’s pole lap from last year to Paul di Resta’s back-to-back analysis of Hamilton’s and Vettel’s 2015 laptimes on Sky earlier today (which I don’t have footage of yet), the Mercedes looks incredibly imbalanced this year compared to last.

The W06 was suffering both understeer into the corner and oversteer on exit, compared to just a touch of understeer on last year’s W05.

You could clearly see the suspension blowing through its travel during Hamilton’s lap this year, suggesting that Mercedes were actually running higher tyre pressures than normal – the tyre acts as the majority of the suspension with a small spring/damper setup to control any larger impacts.

This was certainly the case for Rosberg, who got a radio message before his first run in Q3 which said he would run a set of rubber “without the rear tyre bleed” for his final attempt. This implies that Mercedes warm the tyres in the blankets to a certain temperature/pressure (the two properties are linked), reducing the pressure before they are put onto the car.

Vettel also looks more confident with both the front and back end of the car, particularly in S3. Hamilton was 0.5s slower in the final sector than Vettel, and a whopping 0.6s off the benchmark Daniel Ricciardo. The Briton avoids taking too much kerb, feeling at risk of putting the car into too much oversteer, although he doesn’t really have the front end grip to get the car onto the kerb anyway.

Conclusion

The first thing Lewis Hamilton was asked about in his post-qualifying interview was (obviously) why he was so far off the pace. His answer, “Tyres.” – summed up nicely. But if we concluded that the latest minimum pressures were not to blame for their dismal form, why are we still talking about the black rubber rings?

It’s all to do with their operating temperature window – a range of temperatures in which the tyre works at its best. You can have a lot of useable downforce, but if the tyres aren’t in the right window it’s all pointless.

All the compounds of tyre Pirelli make have their own unique operating windows and the teams generally pick a tyre to build the car’s setup around. Mercedes are generally able to switch on the harder compound tyres better than the softer ones, i.e. the Medium and Hard compounds. Logically, it makes sense to have a strong car for those types of tyre as they are the most used compounds on the calendar.

It became clear even during testing that Ferrari were very much focused on getting the SF15-T dialed in to the Supersoft tyre. They spent most of their qualifying simulations on that compound and clearly the results are paying off in Singapore.

Both Mercedes drivers were left baffled as to why they couldn’t get the tyres into their window whereas the others could. So what happened?

Explanation

It seems that Mercedes could have got the balance between tyre pressures and suspension setup a bit wrong and tried to compensate by piling on more aerodynamic components as the weekend progressed.

From my point of view, it looks like the team have decided to be persistent with their unique suspension setup (if a little softer than usual) whilst playing around with tyre pressures too much. No matter what they seemingly tried, it looked extremely difficult for them to generate tyre temperature whilst actually having a good platform to tackle all 23 corners.

The car didn’t look too unpredictable, just incredibly unrewarding whenever the driver turned the wheel. There was an overall lack of grip.

Ferrari’s stiffer suspension looked like a rough ride for Vettel on his pole lap, but at the end of the day he was able to get the tyres into their operating window and exploit the car’s true potential. This all started way back in February during their many Supersoft tyre runs in Barcelona.

By Toto Wolff’s own admission, the team failed to find the right setup of the car for the cooler-than-expected track temperatures. He said “many various factors” contributed to their shortfalls, but my overall suspicion is that failing to adapt the setup of the car for unexpected conditions has really caught Mercedes out.

It’s like they went down a setup avenue at the start of the weekend which became impossible to clamber back out and start over in time. Rosberg even said that he “went full circle” with the setup from FP1 to Q1, which simply suggest that there was no time to explore any other options.

So overall, even after re-reading this myself, there was no one reason as to why Mercedes were disappointing in Singapore. I’d like to think that I have narrowed it down, though, but let me know what you think!

Expect them to be back to their best very soon in Japan…

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s