In 1993 it was back to basics for Raider Motorsport after team boss Maurice Rissman decided to have a little fun and try his hand at karting. Using a somewhat antique chassis (Demon X8), the RMS team entered the last three rounds of the 1993 Technophone Kart Blanche Championship, an 11 round series held at Oran Park, Lithgow, Orange and Newcastle circuits.
Promoted and ran by the ultimate renegade, Phil Ward, the Kart Blanche series was also a renegade in that it was sanctioned by neither C.A.M.S nor the A.K.A. However, whilst this may have hindered those chasing ‘sanctioned glory’, it certainly did not hurt the championship’s reputation &/or ability to attract major sponsorship and many National, Junior & Senior competitors, as well as many budding, present, and former circuit racing drivers including Remo Luciani (5 times Aust Champ), Darrel Smith (World Cup Champ), Siggy Schuler (F5000, F-Atlantic F-Holden), Phil Ward (Aust. Sports Sedan Champ), James & Brad Ward (Aussie Racing Cars), Leigh Wright (AKA & CAMS Champ), Graham Watson (Aust Gold Star Champ), Barton Mawer (multiple CAMS & AKA karts, F-Ford, F3, Champ Car), Pat Purcell & Lynton Wetone (Bob Jane T-Marts) plus many many more.
As a karting novice, Rissman won the three last rounds of the 93 series generating considerable controversy. Allegations were quick to rise of engine cheating by the Raider Motorsport team and being no stranger to ‘flexing the rules’ himself, series promoter Phil Ward told Rissman in no uncertain terms that he “could not have won so convincingly without cheating”. Ward went on further suggesting that should he decide to compete in the 94 championship Rissman can expect to be “scrutinized with a magnifying glass”! No amount of refutation, including an offer for Ward to take the engine and have it examined, managed to change opinions, and so the cast was set for the coming year’s championship; it would be won at any cost!
What started out as a bit of fun soon turned into an assault equal to anything the team had ever undertaken. With sponsorship from BMC Australia, HIR Services, BMC Plumbing, and National Hire, Raider Motorsport purchased what all research suggested was the best kart for the task at hand; a DPE Arrow AX5. Two new Yamaha Clubman engines were sourced and sent to renowned Tasmanian engine builder Guru’s Engines, to be stripped and rebuilt to AKA specification.
Having received the new chassis well in advance, early testing revealed the same problem the team experienced with the archaic X8, understeer, and although the team managed to increase rigidity and reduce the effect, no amount of structural modification and chassis tuning could overcome the inherent problem. Although the AX5 was quicker on new tyres, the RMS modified X8 was better after the tyres were worn, so the team elected to use the older chassis until a fix for the AX5 could be developed
Despite days of testing and several sets of tyres, the AX5 could not maintain consistency past six to eight laps after which lap times fell away alarmingly. Surprisingly, all symptoms were reminiscent of the team’s Spa Formula Brabham disaster. To overcome the soft chassis without adding weight, the team constructed a mini flex-rig, which showed precisely where the Arrow frame was vulnerable, then set about designing a carbon/Kevlar/foil honeycomb composite undertray which included a diffuser that, theoretically, should produce a modicum of downforce directly below the driver’s seat. After some fine tuning the chassis was instantly fast and won convincingly in round 2 of the series held at Lithgow raceway.
With the chassis now considerably stiffer it became extremely sensitive to pitch, with both under-steer and over-steer able to be controlled by front and rear height adjustment. However, back-to-back testing at high-speed circuits found that increasing rear ride height to overcome understeer did reduce corner speed through loss of traction, and the cause could be attributed only to insufficient grip (tyres too hard) or loss of under-kart down-force due to the undertray being higher from the track surface. Further tests found that the maximum grip level was achieved when the undertray was almost on the ground, but this resulted in the tray actually wearing away at locations where it did touch i.e., corners, ripples, bumps etc.
Other karting innovations introduced included a ram-air inlet system that pressurised the clubman air-box thus increasing performance. Fuel enrichment was monitored via an infrared exhaust pyrometer that had a digital display mounted on the steering wheel. This produced significant horsepower gain but relied on extreme vigilance with mixture control to avoid piston seizure or burn-out at high speed. Raider Motorsport was also the first kart team to introduce ‘ship to shore’ communication, a 2-way radio system which allows a driver to talk to his pit crew whilst on track.
To overcome this the team machined titanium skid pads and remodelled the undertray to locate the titanium plates so as to protrude only millimetres from the underside. To achieve ride height change without effecting undertray position, threaded inserts were fabricated at all undertray mounts, and these could be wound up or down to maintain the desired clearance regardless of what height the chassis sat. In time the undertray would become a bone of contention at sanctioned meetings and lead to an amendment in both CAMS & AKA rule books to make it illegal, but not before Raider Motorsport and Maurice Rissman would win the 94 KB Telecom series, an eleven round championship in which they would visit the podium on ten occasions, missing the one podium only due to a large crash in practice for round ten. Briefly knocked unconscious in the crash, Rissman managed a best result of sixth overall on the day, but the result had little effect of securing the series.
As the 94 season drew to a close RMS was well into designing a new chassis they would build in-house, using much of the tubing knowledge from their Group A and V8 Touring Car chassis building experience. The team had also been approached to field an additional three karts for paid drives. The new chassis would incorporate a number of innovations none more controversial than a quasi independent rear axel that would allow minor amounts of negative camber to be introduced at the rear of the kart to help increase, or decrease, rear grip as required. The design would also include a carbon composite nose that attached to completely redesigned full width/length undertray.
The new nose would include a low pressure area across the front axel line to improve grip and remove some of the pitch sensitivity. Changes were also planned for the rear diffuser in a bid to improve rear grip while allowing introduction of the new adjustable rear axel. However, what was presented as an opportunity to enter the soon to commence Two Litre Touring Car Championship signalled the death of the karting programme which in hindsight was most likely a blessing as both CAMS & AKA rules for the coming season virtually eliminated much of the innovation destined for the RMS chassis.