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Click any of the images for a larger view.
 
 

 

 

"Krakafati", my own R5 race buggy.
  R4 with 10" wheels (old T.O.R.C. regulation size).
I've now been informed; this aluminium extrusion is a drill centring jig. It is a very useful profile to use with a couple of G clamps for aligning tube joints when building a chassis.
Homemade tube clamps and positioners made from steel angle. These are invaluable for positioning parts of the chassis for tack-welding.
Dozens of them can accumulate after a short period, so it makes sense to engrave their angles securely into them for future reference.
These tube notchers are very useful for small scale chassis production. They use readily available bi-metal holesaws to cut the fishmouths. Click here for plans to build your own notcher.
Carborundum or diamond coated drums can also be used for grinding fishmouths accurately to shape.
A perfectly level chassis stand is essential for accurate building.
This is the beginning of one of the R82s chassis.
 

 

 

A partially completed R5 chassis.
 

 

 

Custom engine mounts and chassis brackets made from RHS and SHS.
These readily available stamped chassis tabs should be avoided for mounting heavily loaded items such as wishbones. The single-plane contact with the chassis can easily lead to cracked welds or, at worst, pull a chunk out of the chassis.
This design of single-shear chassis tab is much better. It has a short return to help spread the load along the chassis tube.
  This stamped and folded bracket is a good example of a double-shear wishbone bracket. The load is well supported and spread along the tube and the bridge ensures the bracket sits square to the tube.
Power to weight is a major factor in racing. These hollow fasteners made from chrome moly tube can save a few kilos when multiplied across the number of fasteners in a race car.
Seldom seen now, but this bracket illustrates the correct method of mounting a rod end or bush in double shear. The bolt passes through a second, free-floating spacer that sits within the large hole. No crush load is placed on the bracket.
These quick release single-shear shock bolts make life easier when initially setting up spring rates.
  These small tabs are the best and simplest method of securing hard brake lines to the chassis at the point where they meet the flexible hoses.
These saddle mounts are very useful at the setting up stage for temporarily mounting items such as the radiator etc. They can also be used on the finished car for locating fire extinguishers, fuel pumps etc.
They are held in place on the chassis by worm-drive clamps, and the short weld beads on the saddles prevent the clamps from slipping off.
A more solid and semi-permanent solution to the saddle mount above. These saddle clamps are mounted in pairs and securely bolted together.
They can have just about anything welded to them and will support relatively high loads.
 

 

 

If elements of the chassis need to be demountable, such as the rear of the chassis for engine removal, then these tube joiners are the answer. These are multi-plane joiners and are welded into the chassis tubes in similarly oriented pairs.
  These single-plane tube joiners are more secure but if multiples are used, they must all be mounted in an identical plane.
Finished R5 bare chassis.
An R82s chassis ready to be fully welded.
Different chassis configurations. The Wasp cockpit is very small.
R4 & R5 use shortened Suzuki steering rack.
 

 

 

Welding a nut onto the end of a tube is no way to mount a rod end as it won't offer enough support and if not concentric, can break the weld or snap the rod end.
The correct method is to use these ferules. The plain round ferules are used in the ends of wishbones and the hex ones are used for tie rods etc where they need to be restrained from turning by a spanner.
Sturdy jigs are essential to ensure repeatability of accurately made wishbones.
R82s trailing arm and jig.
 

 

 

Using 4130 chrome moly tube for lower wishbones means the tube weight can be kept low for a relatively high yield strength.
CroMo can be tacked with a MIG but should be fully welded with a TIG.
 

 

 

 

Where pivots rotate in a single plane, polyurethane bushes offer a long lasting and cheap alternative to rod ends.
PU is quite elastic and offers some compliance.
  They are mounted in pairs in a sleeve which is welded to the wishbone tube. The stainless steel crush tube through the centre of the PU bushes prevents the chassis bracket from being over tightened against the bushes thus preventing the whole assembly from rotating.
  These bushes are turned from acetal (Delrin in the US) which is a much harder plastic than PU. It is also more slippery and therefore is very good for making suspension and brake pedal bushes etc.
Bird's eye view of R82s wishbones and hub.
  Q: How do make your rod ends achieve the high angles for steering when their rotation angle is specified as only 16°?

A: Make some high-angle spacers.

  The high-angle spacers effectively increase the usable area of the rod end's ball thereby allowing it to rotate further within its housing.
The bore is reduced as a result, but that's seldom a problem as the joints are chosen to be over-rated for the purpose. The bolt used is normally one or two sizes smaller than the rod end's bore.
 

 

 

Here's an example of rod ends mounted both horizontally and vertically. The vertically mounted rod end in the tie rod is seen here at ride height.
 

 

 

 

 

The high-angle spacers can clearly be seen here working to good effect at full droop.
Note the fully extended shock strap which prevents damage to both the shock (when fitted) and the rod ends from over extending.
 
 

 

 

 

Aluminium hub and pierced Cauliflower disc reduce unsprung weight.
The Cauliflower discs also run cooler than solid discs and scrape grit and mud from the pad faces. This one has just been laser cut and is awaiting grinding and final machining.
The simplest method of altering brake bias is with one of these brake bias adjusters. It is mounted close to hand and installs in the brake line.
By rotating the knob, the front to rear bias can be adjusted to compensate for calliper/master cylinder differences or prevailing track conditions.
 

 

Another method of altering brake bias is by using a brake balance bar which installs in the brake pedal. The bias is then adjusted by a cable and dash-mounted knob which moves the spherical bearing relative to the two master cylinders.
It's a heavier set-up than a single cylinder with bias knob and the cable and bar can jam with dirt.
A typical master cylinder with integral reservoir.
Over-hung pedals are the best set-up for off-road. Floor-mounted pedals attract muck which can impede their operation and reduce their life.
Large orange dust lights and red brake lights are mandatory for racing.
Mechanical brake light switches can fail due to the ingress of muck. These brake light switches are integrated into banjo bolts. They simply install in a calliper banjo fitting and the wires are hooked up to the brake light circuit. Fool proof.
Small left and right hand bike callipers are becoming thin on the ground, but these compact Wilwood callipers are a good alternative.
For trail driving, some people have requested a handbrake. This suitable compact mechanical/hydraulic calliper can be found at the rear of most late model Volkswagen cars.
A lighter alternative is a fully hydraulic handbrake system. This handbrake simply hooks up to the existing hydraulic rear calliper. The only down side would be if the car's brake line suffered a hit. Then there would be no brakes available at all.
 

 

 

 

 

The main purpose of the cassette is to locate the CVs as low in the chassis as possible to obtain the maximum wheel travel.
The relationship between the CVs in the cassette and rear upright are clearly visible here.
The steel cassette sides are laser cut for accuracy.
 

 

 

 

The single in-board brake disc is mounted directly onto the end of the input shaft.
 

 

 

 

 

The final drive ratio can be quickly changed with these taper-bore sprockets.
 

 

The R5 upright and CV.
 

 

 

 

The R5 CVs are lightened to reduce unsprung weight by removing excess material from their periphery.
 

 

 

A fully race-prepped CV as fitted to the R6 and R82s.
  On the left is a standard CV cage, which is perfectly OK for a lot of the time. On the right is a honed, polished and heat treated chrome moly cage for racing.
 

 

This axle gauge is used for establishing the correct axle length.
Lengthened standard axles work perfectly well, but they should only be run in their original orientation to prevent the possibility of stresses unwinding them. The band of red tape indicates the inner end of the left hand axle.
The splines of this OEM axle have twisted off because its orientation wasn't observed.
 

 

 

 If you want the belt and braces version, then billet axles are the way to go.
 

 

On the right is a typical OEM axle with its two circlip grooves. On the left is a new billet race axle.
Gun-drilling the axles removes approximately 4kg without reducing strength.
  To achieve maximum axle angularity (and thus maximum wheel travel) the standard boot flanges are replaced with these wide mouth billet flanges.
  For ultimate clearance, the boots are mounted on the outside of the super flange like on the R82s.
  This is a standard over-the-counter CV boot.
  This is a better quality boot used for racing.
  This is a "Super Boot" for mounting on the outside of the super flanges.
These are standard boot clips, though I just use Nylon cable ties.
Billet axle installed on my R5.
The polished outside half of a three-piece 15" aluminium wheel rim.
  These are two-piece 10" aluminium wheels fitted with Rorty beadlocks and Dingrings as fitted to the R4.
This is a two-piece 12" front wheel rim.
This is a 12" Dingring.
  Q: How do you make tight turns in the headers to enable them to fit in a small space?
A: Use donuts and cut them into segments.
All tube must be measured and marked from its centreline.
A band saw with a machined jig like this is a really useful way of making accurate cuts in exhaust bends.
Both ends of each segment must be perfectly square to avoid gaps.
Slip joints can be made by welding sleeves over the ends of adjoining tubes, but a lighter and more attractive method is to use an exhaust pipe expander to form perfect slip joints.
A heavier alternative to slip joints is the bolted joint. These three-bolt flanges ensure even compression of the exhaust gasket.
Header segments are taped together prior to tack welding and subsequent full welding.
My M8 Austen from the UK began with a plate to build his headers on.
Here's Austen's well designed, partially completed header.
It is essential to get all the primary pipes the exact same length. Bend radii should be as large and smooth as possible. My own R5 exhaust.
  Ceramic coating a mild steel system can help protect it and also offer a small performance gain.
Bike cans are an obvious choice but can be heavy and restrictive. Some perforated stainless tube, some glass wool, a length of aluminium or stainless tube and a couple of spun end caps are all that's needed to make a better can.
Keeping the bike engine's oil at optimal operating temperature is essential for performance and longevity. Conventional oil coolers can become damaged or clogged if mounted in an exposed area. These oil-to-water coolers are highly efficient, compact and aren't as susceptible to damage.
A view from "The Office".
R82s aluminium steering wheel blank prior to folding and finishing.
This adjustable steering quickener can alter the steering ratio to suit different tracks and conditions.
  Once fast laps are achieved, an electric shifter may be on the shopping list. They can be fiddly to set up, but do offer hands-on-steering-wheel gear changes.
  Here are the up and down gear change buttons mounted close to the thumbs on a cast aluminium steering wheel.
Unless there is direct line of sight between the two lever pivot points, Morse type cables are better than rods for manual gear changes.
  These ball joints attach to each end of the cable keeping the dirt out and eliminating backlash.
  If clevises must be used, these ones with quick fit pins are a good choice.
R4 gear stick. Note ignition interrupter switch and cable/hydraulic clutch lever attached to the gear lever.
Use only the best quality cable and Teflon lined conduit for all other control cables.
  Make sure the cable isn't overheated when soldering the nipples on or the nipple and the end of the cable could break off.
Fasteners without some locking device such as a jam nut or lock nut can sometimes rattle loose with potentially drastic results. The simplest solution is to thread some thin stainless wire through a small hole in the head of the fastener and secure it to either an immoveable object or another fastener in such a way that it can't undo and fall out.
 
Some high-end fasteners are available with pre-drilled holes, but drilling them isn't such a problem with this handy aluminium jig and hardened steel drill guide. It handles both hex head and socket head fasteners.
This diagram illustrates the correct method of safety wiring fasteners.
Attaching removable body panels can be simplified by using these self-ejecting Dzus fasteners.
They are available in a large range of styles, sizes and grip lengths.
This is a preformed Dzus tab that is welded to the chassis to receive the Dzus fastener.
The same dimpled holes can be made in any thin sheet or panel with dimpling tools.
This centre punch transfers the hole in the Dzus tab accurately onto the corresponding body panel.
The end of a Dzus fastener has a helical slot which engages with one of these springs when pushed and turned clockwise.
The spring is pop riveted to the two small holes in a Dzus tab or panel.
 
These hollow dimplers can be either bolted together or used in a press.
Bolting small hollow dimplers together is a simple operation.
Apart from making dimples for Dzus fasteners, dimplers can be used for reinforcing lightening holes in thin sheet and body panels etc.
Air filter plates must be sealed and securely mounted to the carbs.
Large oiled foam filter replaces original airbox and flows substantially more air - and that means more horsepower!
TIG must be used for welding aluminium neatly.
  As much of the electrics as possible are kept up front, out of harm's way.
  This is a race buggy wiring diagram in its basic form.
  Battery master switch for cutting all power in and out of the electrical system.
  This BMS has a diode to prevent alternator damage.