Bathurst Weekend Update | 8 Minute Read

Bathurst 2017 | Weekend Update

Firstly  we need to look at the weather and I am writing this at 06:15 on Thursday morning and  overall things look good for practise, qualifying and top ten. Predicted temps for Sunday have been sunny and clear hovering around the 26-27C mark over the last few days but see that these have dropped to 22C and possible thunderstorms for the afternoon. I am pulling info from two sites and both show Friday as being the anomaly as far as temps go, with a maximum of 16C and a 25km/h wind. We will keep an eye on this because from my experience at the mountain, where no rain was predicted for race day, we had a downpour lasting about an hour during the mid-point which shook things up a bit. I had the distinct impression that Bathurst was a little like Cape Town where one could have four seasons in one day.

On to some tech info on the cars for those who are interested.

1 –

All cars run a common race chassis and common safety cell or cage assembly onto which the common suspension parts and various body structures for the different makes are attached.

2 –

5.0 Litre V8 Engines are unique to each manufacturer and intriguingly we have the American based pushrod motors from Ford and GM Holden running competitively alongside the four valve Nissan OHC mill. The engines are controlled brilliantly by having control camshafts, max 10:1 compression ratios and Rev limits of 7500R/min.

Engines do have freedoms to move power bands & shift the grunt to a degree, up or down the rev band but all engines are limited to a max Total BHP across the rev range (will explain how they do this in future posts)

Racing fuel is a 85/15% blend of Ethenol and Petrol (E85) with a Ron Octane of 115

The combination of specs noted above make for excellent power (630 to 640 Bhp for all engines) and brilliant reliability. Engines do roughly 3000km between teardowns ( they call servicing) and most components last to 6000Km.

3 –

Gearboxes are in fact transaxle assemblies mounted at the rear of the car and have sequential shift patterns like a motor bike. Axle ratios are stipulated for the various tracks by the race organisers.

4 –

Aerodynamic performance is homologated on each body type allowed into the race programme. Both downforce and aero are known factors and all car types go through extensive testing to ensure similar performance between brands.

5 –

Tyres are control tyres supplied by Dunlop and available in two compounds

6 –

The power and aero achieved allows maximum speeds of 300km/h at Bathurst and that is in a bend called The Chase….spectacular to watch the cars dancing through that right hander.

7 –

Some of the adjustments able to be controlled by the driver include fuel mixture (lean, rich for fuel saving), roll bars front/rear and brake balance.

All the above may sound controlling but necessary. The regs provide the two aspects absolutely critical to good racing, similar performance and first class reliability. With those two aspects in the bag it eventually comes down to car set-up, driver capability and to a small degree, the ingenuity of engineers on minor areas allowed on engine freedoms …..and that is exactly what we see on the track. At the last race at Sandown, qualifying had the top 24 cars 1.06 sec apart…..

THURSDAY PRACTICE

Things kicked off in style this morning with three practise sessions done and dusted, a number of crashes and surprisingly a Holden quickest for the day a fraction off the all-time fastest ever (2015) qualifying lap of 2:04.9097. To be fair, the Falcons looked ominous with both the Prodrive and Penske cars running strongly.

The perennial difficulty in how to decide the set-up compromise between ultimate lap times and good tyre life are faced by all teams. The switch back to 2016 rubber does not seem to have had any negative influence, however, I am still of the opinion that the Fords are easier on their Rubber and this could be the winning trick.

In line with current form the man holding a record number of poles this year, Scott McLaughlin put in a blinder in the V-Power Falcon early in third practise with a 2:05.127 to go over a second quicker than the pack. The rest slowly closed in but still off the pace until Davey Reynolds in the Erebus Holden popped out of nowhere with a 2:05.0932. This showed the Holden 888 guys a clean pair of heels, that on top of  van Ginsbergen attacking the wall at the dipper and doing fair damage to his car. ‘Gizzy’ did not have a good day with two additional ‘offs’.

No easy-to-read pattern yet with the exception of the Fords being generally  quick as expected. The pattern will appear tomorrow and we look forward to Official Friday afternoon Qualifying which will be streamed on Superview.

More soon….

By | 2017-11-24T10:11:25+00:00 October 6th, 2017|Categories: Australian Touring Car Racing|Tags: , |0 Comments

About the Author:

I have been in the motor industry all my life and despite spending 20 odd years with Datsun/Nissan, remain a GM man at heart.

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