Supercars reverts to old Bathurst 1000 drop gear
Thursday 28th September, 2023 - 2:34pm
Supercars has reverted to an ‘old’ drop gear ratio for next week’s Repco Bathurst 1000.
However, that has been changed back to the 0.931 ratio (29/27 teeth) which was implemented in 2015 and remained in place for the balance of the Car of the Future era, including Gen2.
The 0.909 is now one of the back-up ratios which teams must bring to Mount Panorama, the other being the 1.000, per the Further Supplementary Regulations which have been confirmed today.
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Notwithstanding the potential for the magic 300km/h to be reached on Conrod Straight again, the initial move taller was a decision motivated by considerations of reliability, specifically whether engines would hang on the rev limiter for an excessive period of time before drivers slow for The Chase.
Speedcafe understands that the reversion has occurred because of delays in supply of the new gears, noting Mount Panorama already had the tallest ratio of any track, meaning teams may not have received them before trucks are dispatched from workshops.
It is believed, however, that the new gears will be on-hand at the track and thus will be used if a change to the 0.909 is indeed deemed necessary after Practice 1.
Drop gears have changed a handful of times, relatively to 2022 specifications, during the season, with Supercars having made allowances for back-up ratios given this year is the first for the 5.4-litre, Coyote-derived quadcam Ford engine and 5.7-litre, LTR Chevrolet pushrod.
Another change which has been made for the Bathurst 1000 is an increase in the allocation of brake pads and rotors.
Each car will now be allowed two brand-new sets of front rotors and three brand-new sets of front pads, plus two pre-marked (used) sets of each which may be used during practice only.
Unlike the Sandown 500, where only one set of front rotors was allocated for the race, teams thus have the option to change rotors during Sunday week’s 161-lapper.
Notwithstanding that teams even considered changing rear brakes at Sandown, as evidenced by a rule in the Further Supplementary Regulations 2 confirming the procedure for such work, most cars apparently got through the race without changing pads.
That was certainly the case for the victorious #88 Triple Eight Race Engineering Camaro of Broc Feeney and co-driver Jamie Whincup, the former of whom confirmed he felt some brake fade on the run home but that his car was otherwise reliable.
“We didn’t do a brake change in there, so you feel a little bit in the brakes towards the end there, but, car-wise, they were fine,” he remarked.
In the seemingly unlikely case that teams change rear brakes at Mount Panorama, the engine must be turned off beforehand, which is a practical necessity due to the operation of the line locker.
After brakes are changed, the engine may be restarted, and the line locker must be re-engaged before the pit stop is complete.
Practice 1 for the Bathurst 1000 starts next Thursday (October 5) at 13:20 local time/AEDT.