Hi Derrwint & others,
I'm having trouble opening those jpeg files of the SCW article, so my recollections of the Don Holland car might not be in sync with what is written there. Anyway, here goes. In 1977? Don and co-driver Tery Shiel were disqualified from 2nd? in class at Bathurst. Though I believe the car had been run in that guise for over a season, they were never the less outed as the car's engine was found to be fitted with an exhaust manifold & associated parts from a non-emission controlled engine RX-3 (Australian-delivered 12A-engined RX-3s all had the big box-shaped thermal reactor bolted there instead of a conventional cast manifold).
Don was not impressed and stopped racing there & then. Terry bought the car and Michael Saad from Penrith Mazda continued to support it. I was racing a less-developed RX-3 in Qld & Amaroo Park around that time. My sponsors, B & J Tyres then bought Terry's car on the condition he partner me in it at Bathurst in 1978. As has happened more than once, Terry rolled the yet-to-be-delivered RX3 at the final Amaroo round at the end of August! He then bought a road car and worked hard to swap all the mechanicals over in a few weeks. Everything stayed bolted on and we came 2nd in class, 50-something seconds behind Steve Masterton's Capri! I was thrilled/p'ssed off to be runner-up to him in the innaugural Bathurst Rookie of the Year award. I'm unsure of the speed advantage over other RX-3's Don's car had back in its non-emmission guise, but I do know the string of Bathurst successes were largely due to two other factors.
Firstly, Don and Terry were both excellent racers & race car developers who had honed their talents in the cut and thrust of Mini racing. Of course, so had Barry Jones. He had a fierce rivalry with Terry which carried over from their lightweight Minis to RX-3s. In 1978 Barry had the second fastest RX-3 at Bathurst (of course we both had three Capris on the grid in front of us). Anyway, at that stage, our car & team had benefitted from far longer development than Barry's, courtesy of Don Holland and Tony Farrell who had raced it as a semi-works car.
The second advantage we enjoyed over Barry and all the other Rx-3s were tyres! Don had several years earlier determined that gearing the Mazda tall for Conrod Straight would negate any disadvantage up the mountain. If you look at any pics of our car at Bathurst you will soon spot the difference. We ran rear Dunlops with a 550mm profile (at other tracks we used 500 or 525). These 550 were special order from Dunlop in Japan and only available in limited numbers. I'm unsure whether any other RX-3 drivers ever tried and failed to obtain them. Scary to think that, thanks to them, we were travelling almost 130mph before pulling up at Murray's Corner with only 9" vented dics with 4-pots on the front & Mazda 808-sized drum brakes on the rear!
My next outing in the RX-3 was the following month at Surfers Paradise Raceway for the 500km race, which was part of the Australian Manufacturers Ch'ship. On the opening lap I clashed with the Rod Stevens' Escort RS2000. He turned me around in the fast left hander on the back straight, from where I resumed in last place, determined to make up some lost ground. Unbeknown to me, the nudge had bent over a tyre valve on my left rear tyre, causing a slow puncture. After little warning the tyre peeled off the rim, which subsequently dug in to the track surface just before Reco Hill and over we went. The following week our Team bought a road car and repeated Terry's efforts of several months earlier. 
I hope the above has shed a little light on probably the most significant racing RX-3 in Australia.
