|Car:||Mazda RX2 Rotary|
|Specs:||13B-Turbo, T-60 turbo, Series4 5 speed box, 9" diff, 16 x 7 ROH wheels etc etc. Ran 10.75 @ 127.93 MPH. See full writeup below.|
After deciding I needed something that could keep up with my mates in the V8 brigade that was a little different than the rest I headed off to Selectmaz on 01/09/1998, where I purchased my little RX2 for the sum of $6000. It was a genuine RX2, orange, with 13B Bridge Port, modified Nikki carby, 5spd and 4.1 diff.
The single spinner diff lasted all of 2 months before it gave up so we welded it right there and then. It cost a few axles down the track, but you get that on the big jobs! In this trim the car made approx 120kw at the wheels and ran 14.205 @ 93.35 mph on 12/03/99 at Calder Park. At this stage the drag racing bug bit and I headed to Maztech to find some more power.
Maztech fitted injection to the existing set up that included – Webber manifold and twin down draft throttle bodies, surge tank and EFI pump in the boot, crank angle dizzy for direct fire ignition and a Microtech, MTX-8 computer to run the show. The resulting 170HP saw the demise of the clutch very quickly, so a lightened flywheel and bonded clutch were also fitted. Another trip or two to Calder using these upgrades and still on street tyres, the car ran a best of 13.39 @ 98.51 on 02/07/1999.
Christmas that year saw me spoil myself with a new set of 16 x 7” ROH wheels which made the car handle significantly better than the 13” rims they replaced.
The car went to Easternats in the following April and by the end of the event including making it into the burnout comp finals it had chewed through yet another clutch. At this point the 5spd was occasionally getting stuck in 3rd and I believed that the engine could probably do with a freshen up. I was also contemplating the addition of a decent diff and some giggle gas to push its best times a bit lower.
After some consultation with Promaz, one thing led to another and the freshen up became a full driveline replacement…… enter stage left 13bt, T-60 turbo, series 4 5spd, 9” diff, etc….. etc….. While I was at it we upgraded the brakes using a common conversion with 10” ventilated disc’s being grabbed by Commodore calipers and Bendix ultimate brake pads. Up the back, the 9” had RX4 drums added to help the cause.
It took from June of 2000 until 30th Dec to complete the conversion, being tuned on that last day, two days before I was due to drive it to the Summernats in Canberra. In those 2 days the Saas seats and Sabelt harnesses were fitted into the car and the car detailed to within an inch of its life. An Autometer Monster Tacho was added along the line for accurate RPM readings, as the factory issue wasn’t very happy with the Microtech.
At Summernats the car qualified for both the Horsepower Hero’s (turbo rotary class) and Go-whoa before picking up a dodgy batch of fuel, which blocked up filters, injectors and created all kinds of havoc. The car was limped home and sat in the garage for ages. After having the filters replaced, injectors cleaned and the car re-tuned I took it to Easternats in 2001. The motor at this stage was still an unopened import motor and sadly it expired just 2 laps into cruising on the first day.
A few months later another import motor was sourced and fitted with the idea to lower the boost and just enjoy driving the car for a while. This motor let go in a big way with just 400km under its belt during its first dyno tuning run.
The decision was made and sacrifices made to build a good motor at that point. Enter dysonROTARY. Craig could not have been more helpful. From the 2 motors that had failed to meet the challenge, he inspected all, replaced as necessary, ported and doweled a new motor for the car. While we were at it, an inspection was made of the turbo (read re-co) and a HKS 66mm front wheel was fitted just for good measure. Craig had it all done in a time frame that I thought was impossible for such a job, as I was in the car again only 2 weeks after giving it to him.
Once run in, it was returned to dysonROTARY and was tuned for street driving at a tidy 14psi on Optimax and returned 281kw on the treads. The car was so drivable and user friendly down low with a smooth but forceful delivery of power that I was totally amazed. I took the car up to Springcar Nationals in Shepparton where the throttle position sensor decided that it no longer wished to send out the correct messages and the car consequently started acting up again. Being an aftermarket sensor, one could not be sourced during that weekend and the car was limped back to Melbourne, yet again.
By this stage I still hadn’t had the opportunity to race it and I was getting very itchy to do so. The car was very reluctantly entered into Easternats in April of 2002. This was the make or break event…. I decided that if it let me down again (or more the point I had more shitty luck) that would be the last one! At Easternats it performed faultlessly all weekend and was the last car on street tyres and in the top 8 in the street drags held on the main straight. That was it, I had to race it…. A savings plan was hatched and in May a brand new set of slicks were purchased.
After having some rims made to suit and sourcing front rims and lending some front-runners I finally took the car to Heathcote for its first outing. Two runs on Street tyres gave me a best of 12.78 @ 119.74 before I realised the futility and bolted on the slicks. Best for the day was 11.13 @ 126.16 before the meet was rained out.
With that behind me I had to get to Calder, so off we went on the 25/08/2002 where the car ran its current best ET of 10.75 & 127.93. I was rapt and Craig was well impressed with how the car had performed considering it was still on 14psi and running on Optimax.
The car has since been tuned for 18psi using Av Gas and at Springcar Nationals took out the Dyno challenge (rotary class) with 399hp at the tyres. The disappointment was missing out on overall winner by just 8hp. The car has been raced at Calder with the 18psi tune, however the power seems to be too much for the clutch when it gets such good traction on the slicks and the boost has been returned to 14psi for street duties.
Easternats 2003 saw the car entered yet again, more for advertising purposes than for the events. The car was eliminated from the street drags in the 3rd round by a gassed up V8 Torana this year, but heaps of fun was had in the mean time.