Start modifying cars
Start with a daily driven car.
I can’t stress this enough. If you start modifying a worn-down, tired old car that’s not completely reliable, you’ll definitely regret it. As long as all the major systems are in good working order, you don’t have much to worry about. If your engine, suspension, or electronics have been flaky, sort them out first. If you can’t drive it every day now, your modifications will only exacerbate your existing issues.
Establish a plan and a budget.
With a car project, no matter how large or small, you need to have a clear idea of where you’re going before you fire it up. I’ve put together budgeting tips previously, but the basic idea is to break down your plan into stages, and keep each stage drivable.
Power isn’t everything.
Especially with a daily driver, increasing peak power output is hardly ever the best way to spend your money. Instead, focus on upgrades which make your car more responsive like tires, improved shocks, and more responsive street brake pads.
Power is something, though.
A lot of tuners try to produce more power, when they should be focused on producing better power. For a daily driver, improving torque output and widening the power band should be your top priorities. Trying to make massive amounts of power often leads to peaky power that is difficult to apply on the street, adds considerable strain to the drivetrain, and requires more rigorous maintenance.
Simply retuning the ECU can improve your power curve considerably, without spending any money on new hardware. A more accurate fuel map and ignition map have the potential to make your car much more exciting to drive.
Bolt-on upgrades (such as an air intake, exhaust headers, and a cat-back exhaust) will make the engine sound more aggressive, but do not make a big power difference on most engines by themselves. After re-tuning the ECU, the difference they make will be much more noticeable, both on the dyno and on the road.
Weight where it matters
Most people think I’m silly for preferring a gutted interior to a lush, fully-carpeted floor in my cars. I admit that tearing out all the creature comforts is an extreme way to lighten a car, and that there are more important components to upgrade first. Lighter brake rotors, wheels, and tires will decrease overall rotational mass and improve acceleration, braking, and handling considerably without adversely affecting your car’s comfort level.
Removing excess rotating mass from the engine will put less strain on the engine, and free up more power to be directed to the wheels. This only really applies to older cars, since components have become much more efficient in modern cars. Old engines used crank-driven cooling fans and belt-driven air pumps, mechanical fuel pumps, air conditioning pumps, and power steering pumps. Utilizing electronic cooling fans and underdriving or removing belt-driven accessories frees up power that will go directly to your wheels.
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