Free practice reveals F1 tech secrets

Friday practice for the Australian Grand Prix is the first chance we have had to see the new Formula 1 cars without the garage secrecy screens permitted during testing.

Many teams were expected to bring late aero and chassis updates, but most proved to be more conservative than that, although practice has revealed some technical innovations not obvious during pre-season testing.

Mercedes

The W06 has proved to be as competitive as expected despite no visible Melbourne updates.

While it is a new car, some of the concepts from last year are carried over, particularly the neatness of the power unit and electronic installations.

As Mercedes runs a water-to-air intercooler for the turbo tucked into the rear bulkhead, its power unit installation is especially tidy, with the intercooler's associated water radiator double-stacked in the left sidepod.

A departure for Mercedes on its power unit this year is the new tubular exhaust system.

Gone is the log-style exhaust from last year, which was effectively one open pipe from the exhaust ports to the turbo.

Now, each cylinder has its own exhaust reaching back into a three-into-one collector before a short pipe reaches the turbo.

This solution loses some of the pressure at the turbo, but allows better exhaust tuning for the cylinders.

It was thought that the log-style gained more from turbo performance than it lost from exhaust tuning.

But this year the situation is reversed, so Mercedes has found a way to maintain pressure at the turbo with a conventional exhaust.

Additionally, the new exhaust package is larger within the sidepods, but the exhaust bundle is tucked away tightly negating any potential aero problems.

Ferrari

With all the fanfare surrounding the Mercedes engine packaging in 2014, last year Ferrari also had a very neat and logical layout for its power unit components.

Unsurprisingly, the team retained these strengths this year, but it has still found areas to improve upon.

Firstly, the exhaust system: the F14-T had long exhausts wrapping up and over the engine, also connecting the large high-mounted wastegate above the gearbox.

Now, the SF15-T exhausts are shorter and wrapped in tighter to pass into the gearbox to reach the turbo from below.

This improves engine drivability and also aids aero packaging.

Related to this aero-minded installation, the coolers in the sidepods have been repositioned.

Last year, near vertical coolers splayed out from the engine into the sidepods, creating an awkward exit path for the hot air, resulting in bulky sidepods in order to channel the air out of the back of the car.

This year's car places the coolers in a more conventional flatter orientation. This in itself improves the airflow route through the sidepods, but Ferrari has gone a step further in managing this airflow to keep sidepod volume to a minimum.

The radiators gain louvred panels above and below them, to redirect the airflow through them.

The sidepod inlet feeds a duct to which the radiator is mounted. It's possible to see a row of louvres moulded into the duct, which turn the air 90 degrees to pass through the cooler core.

Then there is a carbonfibre louvre panel mounted over the radiator designed to turn the airflow another 90 degrees to direct it out of the sidepod exit.

This airflow management turns the flow more effectively than larger, more rounded ducts and sidepods.

Lotus

As the team is saving its aerodynamic update for the Malaysian GP in two weeks, Lotus has what is largely a testing-spec car in Melbourne.

The Enstone team is running something other than a Renault engine for the first time since 1994 (when Renault was officially out of F1 it used powerplants based on the marque's V10), and the packaging of the Mercedes created some challenges.

Lotus took a few chances with the Mercedes installation. This mainly affects the cooling package, where Lotus has switched to an air-to-air intercooler now mounted in the left sidepod.

In contrast to the water intercooler used on the Renault engine last year, ducting the large-diameter pipes from the front-mounted compressor in and out of the sidepod and back into the plenum on the top of the engine has resulted in a novel set up.

Now one of the intercooler pipes passes through the fuel tank area, exiting out of the side of the monocoque.

Quite how the fuel tank itself is packaged internally to avoid the pipe must be interesting.

Red Bull

A distinctive feature of the RB11 is the S-ducted nose. The internal duct feeding from below to exit over the nose is fed differently from last year.

The nose sports prominent side inlets, but these do not feed the S-duct. Instead it's fed by a slot under the nose.

This then calls into question what these side vents are for. Red Bull has used similar inlets both for driver cooling by ducting them into the footwell area, and for electronics cooling, with the ride heat\speed sensor mounted in a recess under the chassis. Presumably these ducts serve similar functions.

Although it was a race-winning car, the RB10 had a compromised design last year. To package enough coolers and radiators, the sidepods needed to be long and quite wide. This was because the turbo engine needed large intercoolers to keep the charge air cool.

So Adrian Newey packaged the coolers in a long single panel running from the cockpit back to the gearbox. This necessitated the exhausts sit under the intercoolers, not ideal for thermal management.

This year, the Toro Rosso format of a shorter cooler package has been copied. The coolers now only reach as far back as the engine's front.

To free up space in the sidepods for the forward shift of the intercooler, the RB11 has a large water cooler mounted above the gearbox that is fed by an inlet under the roll hoop.

The repositioned sidepod coolers also force the electronics installation into a tighter space under the radiator ducts.

New details on the car this weekend are a revised fin on the front wing. The little flick behind the cascades on the front-wing endplate are now split into two, for a subtle airflow change.

Williams

The FW37 is a promising car, just as testing suggested. With new turning vanes this weekend, the improvement will be offset somewhat by lost running due to the water leak on Felipe Massa's Mercedes engine.

In common with the late testing aero upgrade, the small black bargeboards ahead of the sidepods were revised, with two vertical slots made into them.

Detail changes were also made to the inner face of the front brake ducts.

Neither is a significant upgrade, but at least it's a sign Williams will continuously develop the car this year.

Force India

It was late to testing, but the VJM08 is clearly a very different car to the 2014 machine, especially around the front suspension.

At its launch, it was announced the car will have a novel hydraulic front suspension.

This is a passive and unlinked system in order to avoid the FRIC and active suspension bans.

Using hydraulic springs allows the team to delete the torsion bar springs from the front of the car.

This frees up space around the front of the monocoque and means the rocker to operate them can be relocated.

In Force India's case, it appears the rocker itself is repositioned, with it pivoting on vertical mounts rather than longitudinal.

This frees up more space inside the footwell for a neater and stiffer installation.

Manor

The challenge to modify a 2014 car to 2015 specification has been considerable.

Rule changes for this year were the new nose dimensions, extended anti-intrusion panels, a minimum slope back from the front bulkhead and new wheel-retention mechanisms.

Although not to be underestimated, three of these rule changes were met by new parts replacing the old specification.

However, the team has been clever in interpreting the regulations and the tricky front bulkhead rule has been met with a spacer mounted to the front of the car.

Last year, the chassis top could be as high as 625mm and the front bulkhead had to be low down at 525mm.

In order to keep the chassis as high as possible for aero benefit, many teams went for a solution that stepped down to the front bulkhead height over a short distance.

The regulations this year mandated the step/slope had to be over 375mm. It was thought the aggressively-stepped Marussia 2014 bulkhead solution could not meet the rules without a new tub or major structural changes to the monocoque.

So what the team has done is to extend the front bulkhead position some 300mm forwards, through the use of a structural carbonfibre spacer.

This spacer looks more like a section of nosecone bolted to the front of the tub, but in regulatory terms is very much part of the survival cell and forms the regulatory A-A bulkhead.

The room this spacer creates allows the step from bulkhead to chassis to be achieved within the regulatory length.

This is a cheeky, but otherwise safe and legal, means to sidestep major changes to the old chassis.