Suspension and Tires
- Created: 20 April 2007 20 April 2007
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Suspension and Tires
Before looking at any add-on improvements to your suspension or tires, you should perform a detailed maintenance check on what you have today.So, for example, look closely at your ball joints and tie rod ends. Is any of the rubber cracked? Excess movement in the tie rods? If you have original 20+ year old ball joints, you might want to be conservative and replace them before accumulating much drivers ed seat time. A ball joint letting go at speed is not a pretty sight. If the tie rod ends are cracked or loose, you can either replace them or, on a 911, upgrade to turbo tie rods. Turbo tie rods, by design, makes the steering more precise. What condition are your struts/shocks in? If there is oil leaking down the sides, there's an obvious sign to replace the strut inserts or shocks. Here you can replace them with stock inserts/shocks or upgrade to something a bit stiffer. Bilstein and Koni are two brands which are popular as replacements/upgrades. In an older vehicle, you may need to consider replacing some suspension bushings. The originals were rubber, and rubber replacements may be available, as well as various harder materials. If you decide on a harder material, be aware that they will transmit more road noise into the drivers compartment. If you have a lowered early 944, be sure your lower a-arms aren't cracked.
Have you had a recent wheel alignment? How about a corner balance? Most people are familiar with wheel alignments. Corner balancing, however, isn't typically done on the family Ford. With corner balancing, you're making sure the weight of your vehicle is balanced amongst each axle and each wheel. A corner balanced car handles much better, as you minimize suspension surprises or odd handling which can arise at the track.
As your driving skills increase, making certain upgrades will create a more stable platform to further increase your skills. Increasing the size of your torsion bars or springs will make a big difference in the stability of your Porsche at speed. As mentioned above, you'll want to consider stiffer strut inserts/shocks, and then larger/adjustable sway bars. Of course, with any of these upgrades come tradeoffs - higher performance may not mean more comfort. A balanced, stiffer suspension is a better on the track, but at some point on the stiffness curve, you might get tired of your teeth fillings rattling during your daily drive. You have to decide what's important to you, so ask around about others experiences with the various upgrades available.
Another suspension improvement involves tires. "R"-rated tires are approved by the Dept of Transportation for street usage, and are constructed differently with a much stickier rubber than your family parts fetcher. While you can run these on the street as your only tires, most have minimal rain grooves, and the softer rubber will wear more quickly than your street tires. Some current "R"-rated tires are Kumho VictoRacers, Yokohama A032R, Hoosier R3S03's, Pirelli P-Zero C's, Toyo Proxes RA1, and BF Goodrich g-force R1's. For drivers education, the Kumho's and Yoko's are good choices, as are the Pirelli's, although they are pricier than the others. The Hoosier's, while an excellent racing tire, wear out quickly. And the R1's aren't too far behind, but people do use them. A convenient source for many of these tires is The Tire Rack. If you plan to get track tires, you might consider a second set of wheels to mount them on. That way, you'll get the longer mileage benefit and rain safety of your street tires, and your track tires will also last longer (not to mention that your street wheels won't get dinged up, which happens at the track). I mount my track wheels/tires just before each Lime Rock event (good time to bleed the brakes) and then drive 45 minutes to the track.
Written by Bill Gregory for the "Challenge", monthly publication of the Connecticut Valley Region, Porsche Club of America.