b'TECH TIP PAGETech Tip 6B: Panhard Bar versus Watts Link. Both have pros & cons. We build our Track- Warriors with watts link packages. It is quick & easy to adjust and handles equal bothdirections. For Road Race Cars the choice is between quick tuning versus optimum lap times. Contrary to popular belief, a level panhard bar does not handle equal left & right. To handleequal left & right, the axle mount side needs to be lower than the frame side. Ron starts theaxle side 1/2" lower & tunes from there. The big difference is, we can tune a panhard bar to favor the 7-9 left or right hand corners of a particular road course & have faster lap times. If we lower the driver side, we have more rear grip on RH corners & less rear grip on LHcorners. If we lower the passenger side, we have more rear grip on LH corners & less on RHcorners. Raising the PHB on those same sides has the opposite effect. Its a compromise that makes a faster overall lap time. Ron has used this strategy for decades to have faster road racecars. You cant do this with a Watts Link, as they will always handle equal both directions.But the BIG DEAL is, the Watts Link pushes the fuel cell back 3 inches! Thats 250# back 3 inches! For best polar moment control & lap times, we highly recommend the panhard bar. Tech Tip 7: Rookie Racers often dont know how critical tire width to rim width ratio is togrip. We often see people putting good width tires on narrower than ideal wheelsusually tosuck the sidewalls in for fender clearanceand experience significantly less grip. Anexample is when Racers want to put a 315 tire with 11.8 of tread on a 10.5 wheel. Not good. The optimum wheel width for grip varies with sidewall height & design. Stock Car bias plytires have 6-7 sidewalls & respond well to wheels around 10% wider than tread width.Modern cars with 18 wheels & 30 or 35 series radial tires have 3.5-4 sidewalls & respondwell to wheels equal to tread width or 2-3% wider than tread width.If the rim to tire ratio is narrow, the sidewalls are bulging out past the rim, and we run less tirepressure to achieve even tread wear. This is bad. The lower pressure is not enough to keep thetire carcass in the proper shape with high G side loads (even worse with taller sidewalls). So, the tires roll under significantly during cornering. This distorts the tread contact pattern. This is WHY we have less grip with narrow wheels. Wider wheels require more tire pressureto achieve even tread wear & this keeps the tire carcass in the proper shape with less roll under. For 18 wheels with radials, treaded or slicks, we recommend:For 315/30-18 tires with 11.8 of Tread, we recommend 11 min, 11.5 is better, 12 is best.For 335/35-18 tires with 12.7 of Tread, we recommend 12 min, 12.5 is better, 13 is best.For 345/35-18 tires with 13.2 of Tread, we recommend 12.5 min, 12 is better, 13.5 is best. Unfortunately, many series rules limit rim size, as they know running wider rims is anadvantage. SCCA GT1 limits the 355/650R/18 fronts to 13 & the 365/720R18 rears to 14.They would both benefit grip-wise with to 1 wider rims.Trans Am limits the Pirelli 320/660-18 to 13 wheel, which is awesome for the 11.85 treadwidth. Similar with the 350/720-18. It is limited to a 14 rim & has 13.10 tread width.39'