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Bathurst 24 Hours Recap
Submitted by SuperUser on Tuesday, November 26, 2002 - 2:40pm


Australia’s inaugural 24hr race was done and won last weekend at the famous Bathurst racetrack 3 hours west of Sydney. Well known for its annual 1000km race each October where V8 powered Holdens and Fords pound the mountain circuit, this particular event was organized to field more than just a 2 make race.



Categories where varied (5 in total) allowing a wide variety of racecars from the wild to indecently mild. Easily the most exotic looking entrant was a Mossler MT900R which appeared to be straight from the Le Mans camp with the most average going to mums shop around 1600cc powered Mitsubishi Mirage hatch. Naturally speeds differences where great and accidents where going to happen. Entered in amongst the field was a lone Mazda Rx-7 raced by the Bob Pearson owned Pro-duct motorsport team.

With wins in 1992, 93, 94, 95 for the 12-hour and 99 in the 3 hr production car race (no longer staged) the RX-7 has a legendary status here that sends trembles down every road in Stuttgart. So much so that Porsche has not returned here with an open cheque book and high ranking officials (ready to accept the trophy on the factories behalf) since their 1995 humiliation.



Since the widening of production car regulations in the late 90’s. The RX-7 was restricted to GTP (2nd class) where modifications where more limited (even more so than other GTP cars) than the better off “Nations cup” category where the Porsches where allowed to venture. As many rotary enthusiasts would know, the rotary powered cars are always undesired when its time for racing against other equals and this case was no exception. (Australian apathy is legendary) They even tried to ban it until the Pro-duct team provided documentation to prove its still sold in Japan. Grudgenly they allowed the RX-7 to stay but it had to be updated from the common series-6 (92-95) specs to the current series-8 (99-02) version.


This actually allowed the car better specs as the series-8 gets bigger brakes, a better diff ratio and more efficient turbo’s mechanically. The rear spoiler is adjustable and a big improvement as is the added cooling from the newer nose. Most importantly though is the separate intakes for the airbox and intercooler meaning intake temps are way down on the previous design.

Come race day and it was blatantly obvious that this RX-7 was the most watched and consequently penalized car by both sanctioning bodies present. In fact just 3 days out from the event saw the team leader receive a letter explaining a new rule change. The RX-7 boost was to be dropped from 0.8 BAR (11.7psi) to 0.7 BAR (10.3psi). The letter stating “Prospective competitiveness” as the reason. The team where quick to threaten legal action asking why the Mitsubishi Evo-7 was still allowed 1.2 BAR (17.6psi) and the Subaru WRX STI was allowed 1 BAR (14.7 psi). Consequently the organizing body dropped their new rule change.



The team owner just put it down to the entrenched fear of it showing up the high priced favorites such as Lamborghini, Ferrari, Porsche and the like. Hence the entrenched bias against it from the top of the governing bodies right through to there subordinates. During the race, the favorites would be lucky to find a single pit officer glancing at their stops. The RX-7 on the other hand would have between 2 and 5 officers watching every action from all angles trying to find any pit lane infringement to penalize the car. Penalties such as a stop-go and start delays where placed on the car as the rush of pit stop stops allowed human error into the creep in and officials to exert their authority. Others would get away murder (so to speak)

Despite the psychological problems of over officialdom Bob Pearson was pleased with the cars qualifying position of 7th with a 2.28 second lap of the 6.2km mountain race track. This placed him at 1st in class and ahead of others in the pure race “Group-1” field. With the race underway at 4pm (Sydney time) the RX-7 settled into trouble free running adopting a slow-and-steady approach as a lot could happen in 24 hours. 5 hours into the 24hr event and they where circulating in 5th position as the favorites began to tumble but around 9pm it was the RX-7’s turn. The driver pulled in complaining of lost power. Fuel problems where suspected, so pump and filters where quickly changed and the car went back out only to return the next lap. The engine was now sounding very sick and the trail was leading to ignition problems. The 13B intake manifold was lifted for the coils to be checked. 3 burnt out coils, 4 black spark plugs and 25 minutes later, the rotary returned. Better but not perfect. Even the ECU was changed but it was to get worse. Trying to push through the problem, co-driver Mark Brame experienced a backfire at 260kph coming down the main straight. Instantly the 2nd turbo shaft sheared from the backpressure wave speeding up the wide open throttle intake piping. The RX returning back to the pits in a massive cloud of smoke.



It was crunch time for the team owner but with 16 hours left the go-ahead was given to change the engine. Any FD RX-7 owner would know how difficult it would be to change the turbo’s with the engine still in and glowing red-hot so a complete engine swap was ordered. Working frantically, the car was pushed back out of the garage 3 hours later and some 130 laps down on the leader. It was 1am and the pit crew where totally exhausted, if the car was to have further trouble its unsure if they would have coped.

The next engine in felt strong and proved ultra reliable. Lap after lap the temperatures held steady allowing drivers to push the car hard and start playing some type of catch-up. By daylight the RX-7 had crept back to a respectable 26th place when it was to lose further time in an incident with a slower car. The clash put the Rx-7 into the wall and damaged the steering. Another return to the pits had the power steering rack changed in just 10 minutes.


By the end of the 24 hours Bob Pearson was pleased just to finish. The 26th placing meaning nothing as it’s the what-could-have-been factor that remained fresh in his mind. “Where going to learn from this. When we get back here next year, it will be with two RX-7’s and we have a full year of sprint racing to develop them even further” he said enjoying a quiet beer with his team. The victory cheers of Holden Monaro fans a few hundred metres away adding determination to his voice.


More info can be found on the official Bathurst 24hr web site at www.bathurst24hr.com


RX-7 performance modifications permitted.

Exhaust (must exit in factory position)
Air filter (must remain inside factory airbox)
Boost (limited by governing body)
ECU (no wiring alterations, must be attached to factory loom)
Brake pads (must use factory discs & calipers)
Shocks (must locate in factory position)
Springs
Clutch (upgraded single plate)

David Morris.

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subject:
RX-7 = fun
author:
No Rotor
date:
December 31, 1969 - 4:00pm
Seems the Aussies are having some fun down there. Pity there wern't more RX-7s racing, might have had a better chance at improving that great race record
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