![\"\"](\"http:\/\/wheeleyandtwooley.com.au\/wp-content\/uploads\/2012\/07\/IMG_0321blog1.jpg\" "\\"IMG_0321(blog)\\"")
<\/a><\/p>\n\u00a0 Work on the front suspension took another week to finish.\u00a0 Work on the rear suspension took another week.\u00a0 Four wheel steering is not allowed in Motorkhana Group 4H Regulations.\u00a0 It was banned many years ago.\u00a0 Because I was using VW Glof Mk 1 front hubs on the rear, I realised that there was a possibility of passively steering these rear wheels if the toe link connecting the steering arm was mounted on the chassis higher than on the upright.\u00a0 Then when the car rolled on its suspension in a turn, the outside wheel would turn outwards, and the inside wheel would turn inwards, with the result being a car that would automatically turn the rear wheels around poles.\u00a0 6 millimetres difference in height was built into the mounting points.\u00a0 The photo below shows the rear wheel steering in action. <\/p>\n Another week was spent building and fitting all the brakes.\u00a0 Then another week for all the fuel systems.\u00a0 Then on 17-4-02 everything was taken off the chassis ready for painting, which took another week.\u00a0 Then the job of re-installing everything started.\u00a0 Along the way, I designed a lifting system into the trailer, consisting of two SHS frames hinged in the inside of the trailer, that normally sit flat with the chassis.\u00a0 The pivot point axles have 3\/4″ chain sprockets on them with a chain wrapped around them.\u00a0 A Goggomobile jack was mounted so that when the nut was turned, the jack extends, and makes both the frames come up together under the car to raise it off the wheels, and leave it at a better height to work on.<\/p>\n <\/p>\n 38 ID x 13 wall Roll Bar Padding was glued onto the cage.\u00a0 Then the bodywork was started in clear acrylic.\u00a0 The car was then taken to the bike expert where it was tuned, new timing chain fitted, and new jets in the carbs.\u00a0 On 6-7-02 the firewall, seat, belts were installed, and the chain for the primary drive cut to length.\u00a0 A standard VW Golf gearbox was fitted to check all the alignments.\u00a0 New master cylinders were fitted on 17-7-02, but bleeding them was a problem because they were mounted on the floor, and the turning brakes high up.\u00a0 All the brake fluid kept running back into the master cylinders.\u00a0 A week later, and a rough wheel alignment performed so that the car could be driven for the first time on Saturday 3-8-02.\u00a0 The rear suspension bottomed out with a 100 kg load, so the suspension arms were relocated.\u00a0<\/p>\n Sunday 24-8-2002 was its first competition at the MG Car Club Ironman event, where the motor did not run properly at low revs, the brakes were very bad, and the rear wheel steering was too violent.\u00a0 The steering ratio was not good, with too many turns needed to go from lock to lock.\u00a0 A week later, new brake balance bars were fabricated to try to solve the brakes, and the rear suspension bottoming was solved by the fittment of new spring\/damper units.\u00a0 Sunday 8-9-2002 was the Queensland Motorkhana Championship Round 5 at Queensland Raceway where the brakes were still bad, the motor still ran poorly, and oil started leaking out of the tacho drive.\u00a0 Things were no better at Round 6 on 17-11-02, but at least the turning brakes were working well.<\/p>\n To solve the steering problem, a Go-Kart style system was built, and together with a new larger diameter steering wheel was tried out on 2-2-03.\u00a0 The steering shaft sheared from the pressure, so a design utilising a modified Renault 10 rack was started.\u00a0 To try to solve the motor problems, a new air box was made from a VW Golf unit.\u00a0 It was all tested out at Round 1 of the QMC on 23-3-03, but the fuel pump failed.\u00a0 New hotter spark plugs were tried, but it started backfiring and running very rich.\u00a0 Testing was halted by a broken C.V. Joint.<\/p>\n At this point it was decided to give up on the Kawasaki Z1000 motor, and get a younger replacement.\u00a0 On 8-4-04 a Kawasaki ZXR-750 was purchased for $1600.\u00a0 Six months later the change over was started.\u00a0 The motor mounts are different, so the old ones were cut off, and new ones fabricated.\u00a0 The exhaust pipe centres are different, so new pipes were manufactured using the old ones as a basis.<\/p>\n In January 2005, when the chain was being fitted, it was found that the newer motor has 5\/8″ chain, so all new sprockets and chains have to be purchased.\u00a0 The new motor is water cooled, so a radiator position had to be finalised, and all the pipes connected up.\u00a0 on 12-2-05 all was ready for a test firing of the motor, but when the isolating switch was connected there was a giant spark in the electrics.\u00a0 A dead short in one of the terminals.\u00a0 Fixed that, and the engine started and ran, but the revs climbed after 10 seconds.\u00a0 An extra spring was put onto the throttle return cable, but no difference.\u00a0 Investigations showed that the choke cable was sticking, so an extra spring was fitted to it so solve the problem.<\/p>\n The first competition with the new motor was on 13-2-05 where the ride height was set too low, but the motor ran well.\u00a0 A new chain path was designed to better utilise the chain, and two teeth taken out of the chain to make it all work.\u00a0 The car was towed out to Roma for a demonstration motorkhana where it kept jumping out of gear on the over-run.\u00a0 When the gearbox was taken apart, it was found that the circlip was not fitted properly to the end of the input shaft, and the pressure on the gears made the shaft slide through the box.\u00a0 On the over-run, the movement caused it to jump out of gear.<\/p>\n New “Lexan” bodywork was fitted to the car just before towing it all the way to Perth for the AMC in 2005 where the chain adjuster came off halfway through the competition.\u00a0 With not enough time to solve the problem, it was loaded on the trailer for the 4,000 kilometre journey home.<\/p>\n A home made steering rack was manufactured for the car in February 2006, and a restrictor placed in the fuel return line.\u00a0 The brake balance bar was removed, and replaced with a simpler system.\u00a0 In June 2006, a reversing mirror was built, but the field of vision was not good enough to use in competition.<\/p>\n Just after the AMC of 2006 (held in Brisbane), an air operated forward\/reverse system was manufactured using a pneumatic cylinder to change direction in the box, powered by a reservoir, and switched by a button on the right hand turning brake.\u00a0 The systen was tested on 8-11-06, and all worked well. \u00a0 Early in 2007, a new smaller diameter steering wheel was built and tested OK.\u00a0 2 degrees negative camber was built into the front suspension to better utilise the front tyres.\u00a0 In July 2007, new front spring\/damper units off a Suzuki RGV250 were tried on the front, and the resultant firmer front suspension made a great improvement to the handling.\u00a0 The steering was still not good, so an “Edge” steering rack from a sand buggy was obtained.\u00a0 It was fitted in October, 2007 with another improvement in performance.<\/p>\n January 2008 saw a major rebuild, and a change of colour to Hammertone Charcoal.\u00a0 It was towed to Rockhampton for Round 1 of the QMC, but somehow water had got into the fuel tank, and it would not run properly.\u00a0 The first test was missed while trying to flush some fresh fuel and metho through the lines, and by the end of the day it started to run at over 6000 rpm again.\u00a0 Next day at Gladstone, it ran better again.<\/p>\n At a private test day on 5-5-08 all the corner weights were tested both with driver aboard and empty.\u00a0\u00a0Caster and camber gauge settings were checked and adjusted.\u00a0 A camera was set up to film the suspension at work, and the results analized.\u00a0 The next week, the old problem of jumping out of gear re-appeared, and it was found out that the circlip had come off the input shaft again because of the sideways pressure.\u00a0 The VW Gearbox is technically running backwards from the Golf design, so the shaft was taken out and washers fitted at the loaded end.<\/p>\n The clutch started playing up in November 2008, and it was found out that the standard Kawasaki clutch master cylinders are pressure bled when new, and so the position of the bleed hole is not important.\u00a0 This was only found out after buying replacement parts at great expense, and so a different type of clutch cylinder was fitted.<\/p>\n \u00a0 At the next motorkhana, the right rear suspension unit sheared off, so Kayaba suspension units were purchased to replace the originals.\u00a0 One sprung a leak, and had to be rebuilt.\u00a0 New 7″ x 13″ rims were fitted for the Wheels on Wide Bay event, but something broke in the gearbox.\u00a0 When the box was taken apart, there were broken teeth on both gears, half a tooth was broken off the diff gear, and the diff pinion severely damaged.\u00a0 The thrust washers had failed, and jammed the gear teeth.<\/p>\n \u00a0 The input shaft was then ground to suit a proper thrust bearing, and all re-assembled.\u00a0 It all worked well for the Iron Man Motorkhana where the car won outright.\u00a0 A new muffler replaced the hot dog unit to soften the harshness of the sound.\u00a0 The plastic coolant header tank was replaced by a metal one in 2011, after the plastic one melted.<\/p>\n \u00a0 Some American brand crossply slicks were tried out in September 2011, but because of the light weight of the car, they did not build up any temperature on the front, and subsequently did not grip well.\u00a0 All sorts of tyre pressures were tried with no better result.\u00a0 So a pair of Formula SAE front Hoosier tyres were purchased to put on the front wheels.\u00a0 Grip was suddenly improved.\u00a0 New lower front A arms were fabricated to get 30 millimetres of caster in the fronts to better utilise the tyres, but this caused a problem on full lock in reverse, where it became difficult to get the car straight again.<\/p>\n","protected":false},"excerpt":{"rendered":" CASPER, the Friendly Special. This is the seventh motorkhana Special built by Alan Wheeley.\u00a0 Casper was the first of his specials that was completely designed by AutoCAD in a computer.\u00a0 The previous special, Gonzales, handled badly because of the lack … Continue reading <\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/a><\/p>\n<\/a><\/p>\n