Is it possible to turn a standard car into an elite rally car? What has to be changed? AMG
The answer must make a clear distinction between what you call “elite” rally cars (those which are purpose-built to compete as “works team” entries in international events), and those used by “privateers” (either as a sub-class in the WRC or national/club events) which are either hand-me-downs from the upper tier or standard cars upgraded by sundry additions and modifications.
Rally rules insist that competition cars – at all levels - must be “homologated”. They must be based on a standard mass-production vehicle, sold in showrooms in specified minimum numbers to the general public.
They must have the shape and use the design systems of what you and I can buy and drive. Homologation technically maps and certifies that.
There are then two lists - one of the items you must have or add for safety, like roll bars, full-harness seatbelts, and automatic fire extinguishing systems; and then a list of other of items you can “modify” or “change”(within limits) …in the engine, the transmission, the drive chain, the brakes and wheels, the frame and bodywork, the cooling system…
The degree of some of these allowed changes is “free” (do whatever you like) others are “limited” by materials and/or system design compliance. That leaves another list of items that must comply with the homologated standard; not systemically changed... but also not untouched.
Ultimately, there is no part of a standard production car that cannot be “improved” in some hand-built and cost-no-object way that will increase power, acceleration, or braking force, or reduce weight, or add strength, or improve balance and traction, or add to the driver’s information and control options, or speed up gear changes, or enhance cooling, or anything – anything at all within the proscriptions - which might sharpen the competitive edge.
The difference in production cost (price is another matter) between elite rally cars and their standard cousins is not a percentage...it is an order of magnitude (x10).
So at the most elite professional level, everything is “changed”, everything that is allowed is added, everything that is not mandatory or beneficial is removed, and every permitted “improvement” is made. Nothing is left untouched.
Works teams do not start with a standard car and modify it. It is purpose-built to the highest permitted specification from scratch by all the technical, physical and economic resources of the manufacturer’s specialist team.
Some of the parts may be mass produced, but even they are optimised and maximised in every detail and by any available means in the original build of the cars that will get a number on their doors. Other parts are one-off tailor-made.
Privateers can sometimes buy a used one of those when its elite day is done, or start with a standard car and upgrade it. At the amateur level, the priority modifications for a basically competent car would be safety extras (rollbar, belts etc.), stiffer suspension, improved tyres, brakes, engine power, cooling systems and underbody protection. These and any other upgrades in the manner and to the extent that the budget allows.
Bear in mind that a change in one thing almost always requires a consequential change in another, so moderate improvement of everything is likely to be more successful than a dramatic change in one item.
For example, power can be increased by changing the pitch of the camshaft, but that means stronger valve springs and polishing the cylinder head ports for air and fuel flow, and probable modification of the exhaust back pressure, and the cooling system to deal with the extra heat generated by higher revs.
And the full benefit of going faster is not just top speed – it is also the rate of acceleration (and the original gear ratios and weight of the flywheel might be anomalous), and no less important to your average speed is how late you can brake for a corner or other hazard.
So, improving your braking force improves your overall pace/time, but it also puts greater stress on traction and generates heat, which have to be counteracted by tyres, air flow systems and weight distribution...and so the chain reactions go on.
Manufacturers could make these modifications as “standard” on the cars they build with minimal price penalty, but almost anything that makes a car more rally-ready will make it less suitable for ordinary motoring.
The point to recognise is that cars that can be driven in a way that could win a World Championship Rally and the same make and model you can buy in a showroom are related to each other…in the same way that the latest super voice-recognition computer is related to a manual typewriter.
The skills required to operate either of those devices to write a letter are perhaps not greater or lesser, but they are different.
Trying to drive an unmodified standard car like an elite rally car would be an interesting experience...and very short. The only question the test would answer is whether the standard car crashed before it broke or broke before it crashed.
And trying to drive an elite rally car to take the kids to school or down city streets in the rush hour would be noisy, smelly, uncomfortable, awkward, fundamentally different, and damnably expensive.
