Car Prep
Some of the steps involved in creating a rally car
Car Prep
Some of the steps involved in creating a rally car
Step One:
Start with a car that can, in theory, be thrown away.
That's right. At any time, a rally car can be reduced to a ball of junk. Those contemplating getting started in rallying should first consider buying a used rally car; one that has the proper safety equipment and a documented past. More time will be spent learning to drive and fine-tuning the car (as needed) than building and developing a whole new and unknown project.
That being said, here at Team Harco, where we have built a few competition cars, we took on a new project in 1999: the creation of a new Pro Rally car. The starting point was a 1990 Eagle Talon TSi with 135,000 miles on the clock (thus the initial cost was not too expensive). This basic car has all-wheel-drive, four wheel disc brakes and fully independent suspension. The engine is turbocharged, intercooled, has 4 valves per cylinder and fuel injection--the perfect candidate for use in the Production GT (PGT) class.
The first things to look at are any problem areas--any structural issues or reliability issues must be resolved before building a car for rally use. The next thing is to study the rule book and determine what modifications are permitted, and what is mandatory.
Let's look at the required items first. I won't list them all--one more reason why anyone looking to get involved must consult the rules. First are the safety requirements: all cars must have a suitable and approved roll cage. We selected an Autopower bolt-in unit (mainly because I got a great deal on it from Steve Gingras). Typically, welded-in cages are safer and will fit better. Both driver and navigator are required to have 5 point (or 6 point) safety harnesses, Snell helmets (SA95 rated or later, beginning in 2002), and approved fire retardant driving suits. The car must also carry a minimum amount of fire suppression equipment (fire extinguishers, or fire bottle), three warning triangles, a tow rope and a first aid kit. Other required items include tow hooks front and rear, and mud flaps at the rear and all driven wheels.
While not required by the rules, a rally car must have a number of other items, due to the nature of the sport. Suitable seats to support the crew are important. We use Corbeau racing seats, but there are many other brands that work as well or better. A calibratible odometer is also necessary to allow the navigator to keep the team on course and alert to potentially hazardous portions of the route. We use an ALFA Pro Rally odometer, though other brands are common. Auxiliary lighting is critical for rallies that run at night--our choice here was Cibie. Also, at night the navigator needs at least one map light to read the route instructions; we use one manufactured by Hella. Most of these later items are necessary but the actual brand selected is entirely a matter of personal preference. The old adage "You get what you pay for" usually applies.
The heart of a rally car is its tires, suspension and brakes. There are many brands and models to choose from, and this is typically where most of the money is spent when preparing a rally car. While it is possible to get very fancy and spend lots of money here, we chose a simple and reasonble path. For tires we have the following options:
Most rallyists will tell you there is no such thing as having too many tires. Since the only part of the car that comes (intentionally) in contact with the road is the tires, they are critical.
Suspension is the next area on the critical path. Suspension systems continue to get more and more sophisticated. The cost of rally suspensions can often be two to three times the cost of the initial (used) car. Again, we chose a more reasonable route and went with a good, strong basic suspension kit. GAB Rally shocks and struts were selected, and initially used with the stock springs. Now, after two full seasons, several Pro Rallies, a couple of Road Rallies and a pair of ice races, I have seen nothing to indicate I should hurry to install stiffer springs. The GAB shocks are that good!
Brakes are the next thing to look at. Depending on the rules, it may not be permissible to change anything other than the friction material. This has been true in our case. We have been very fortunate to obtain support from Performance Friction and use their special Carbon Metallic rally compound (97) linings. Also critical is routine inspection and maintenance of the brake components. Calipers must function properly, rotors must be clean and true, and good brake fluid is also an important consideration. Cryogenically treated rotors are becoming popular and may offer a slight advantage over untreated units. We won a cryo treatment from our results at the 2001 Sno*Drift. After STPR they were cracked (could it be the water splash?), so I have little experience to support them one way or the other.
You're gonna need protection. That's right, there are all sorts of things on the fuzzy side of the car that need to be protected. The engine oil sump is one example. Transmissions, exhaust systems, fuel tanks, brake and fuel lines are all subject to hostile conditions on a rally. There are many materials used to protect these items: steel plates, aluminum plates, high density plastics, etc. are common choices. For our car, we use a 3/16 inch aluminum plate to protect the engine, transmission and transfer case. Until the Thayer's Lake stage at LSPR 2001 this had proven to be sufficient. Now I am looking into a piece that is 1/4 inch thick. We also use high density foam sandwiched between high density polyethelene to protect the fuel tank and the fluid lines running underneath the car. For the most part, these have proven to be effective, though vigilant inspection and maintenance is key.
Now it's time to put it all together. With all the right parts it can be rather straightforward. However, there are lots of cutting, drilling and welding operations that must be undertaken. Without lots of experience in this area, one would be best off looking for that used rally car.
