Basics of tuning and modifying

While Filipinos love to personalize cars, many of us fail to realize that in doing so, there are compromises we should be prepared to make, be it in our driving style, the life expectancy of the parts we replaced or changed, and the associated parts of the modified or replaced component, and even the overall feel of the vehicle. Here are some helpful reminders:

1 Changing/modifying the suspension—the suspension is a complex system of moving parts designed and engineered to work in a certain manner, at a specified state or in this case, ride height. The most popular suspension modification is lowering the car. In doing so, there are some risks, most notable is the lack of suspension stroke or travel. By simply changing the springs and not the shock absorbers, the shock absorbers tend to bottom out completely, accelerating wear on the oil seals of the suspension which ultimately causes their demise. If shocks can last 3-5 years, expect lowered cars with the stock shocks to last a maximum of 3, if you’re lucky.

Another aspect is that braking and cornering performance, especially in rough surfaces is a tricky balance with lowering your suspension. The suspension’s motion helps absorb kinetic energy from braking or cornering to keep the chassis as level as possible. If the suspension runs out of travel or movement, it is unable to dissipate the kinetic energy, thereby adding further strain on the brakes, tires and the rest of the suspension components. Your car will feel rough and skittish under these conditions. If you want to modify the suspension, a good set of matched springs and shocks with shorter but wider shock housings to compensate for the shorter springs will be the perfect ticket for a well-sorted suspension.

2 Installing pillow-ball/rose-joint bushings and camber plates—we all read about the solid, precise and well-connected feel afforded by solid metal bushings such as rose-joints and camber-plates. But the harshness is gives is tremendous especially on poorly surfaced roads, such as poorly laid cement and old asphalt overlays. Your hands and arms will get tired a lot. Plus these generally do not last as long as regular rubber bushings because they generally only need to last a full-season of racing. You have been warned! The same goes for aftermarket poly-urethane and Teflon/Delrin bushings in lieu of regular rubber bushings, harsher, more NVH, less comfortable in exchange for more precise handling and feel.

3 Upgrading to bigger wheels with wider tires—the wheels, tires and the suspension components are collectively identified as unsprung weight,  that is the components of the car that is not suspended by the suspension system itself. Race cars and serious tuners use forged aluminum suspension components and forged aluminum/magnesium wheels to reduce unsprung weight. Why is that? When your car hits a bump on the road, the chassis, engine and everything else in-between the suspension and the tires is supported by the suspension itself and moves freely within the boundaries afforded by the suspension, be it left and right, up or down. But the wheels, tires and suspension are designed to absorb the impart on their own. By increasing the size, heft and crucially the mass of these wheels and tires, you increase the force of impact that works against the chassis and engine, connected by the now overwhelmed suspension. Now you know why bigger and generally heavier wheels and tires really kill refinement and comfort.

Additionally, wider tires do offer more dry-weather grip, but in the wet, are more prone to aqua-planing because the larger surface area doesn’t always make for an efficient surface to evacuate water immediately underneath the grooves of the tires owing to their width. Rally cars that race on loose surface usually have a width of only 205 mm, whereas on tarmac, they make do with a wider 235 mm width tire.

Lastly, wider wheels and tires cause an effect called tram-lining wherein the wheels tend to catch and follow the surface pattern imperfections, making the steering wheel behave like a Labrador on a tight leash! The wider you go past OEM size, the less feelsome your steering tends to be unless a huge amount of wheel alignment compensation/modification is done. This can accelerate wear to the tires. As a general rule, car manufacturers tend to not go beyond a 245 mm width front tire as this gives the best balance of steering feel, responsiveness and front end grip and stability.

4 Installing HID/xenon bulbs—I’ve said it before and I’ll say it again. Xenon/HID headlamps require an ellipsoidal or projector-type lens (the one that looks like an insect’s or an alien’s eyes) to properly focus and project the beam of light down the road. Installing retrofit HID systems on cars equipped with non-HID headlamps without a projector or ellipsoidal lens will just kill your nighttime visibility as the light will be dispersed or scattered. This is dangerous, especially in incremental weather like rain and fog. All you accomplished was annoy other motorists at night with your super bright but all over the place headlights, and blinding yourself at night.  Coupled with blue, violet/purple and green headlamp colors, you might as well drive blind-folded.

If you want to upgrade your headlamps, install a slightly brighter headlamp bulb with higher wattage, ideally in a gold/rainbow/yellow hue which gives better contrast at night and in bad weather driving. Don’t forget to upgrade high-quality relays and proper gauge wires, and ideally replace the socket with a high-quality ceramic socket available from companies like Bosch to better resist melting as higher wattage bulbs generate more heat. Don’t go crazy though and upgrade beyond 100 watts. In my experience, bulbs higher than 100 watts tend to slowly burn off the insides of the headlight housings, turning brown/black, which in the long-term will lessen your night time visibility.

(To be continued next week)