H For Handling - Tuner Tech

From there, we moved to the H-Sport GTI. This had arrived fully equipped and with the following baseline settings: Ride height was set at 2531/48" on the front and 25111/416" on the rear, using the adjustable spring platforms on the Ohlins/Stasis coilovers fitted to the car. The shocks were set at five clicks from full hard (18 clicks total) on the front and six clicks from full hard (24 clicks total) on the rear. The front toe was set at 11/416 toe-out per side and camber was negative 2.2. The tubular H-Sport sway bars were 27mm on the hard setting at the front and 32mm on the soft setting at the rear. The hard and soft settings were determined by the different mounting holes on the ends (the nearer the middle of the bar, the harder the setting). Tire pressures were 30psi front and 33psi rear.

We were ready to go. Obviously the car felt faster than stock since it has a turbo upgrade and stopped better thanks to its Alcon brakes (see p24), but it's still possible to analyze the handling. Immediately, the car drove well through the mid- and high-speed sections, but the rear was nervous through the slower, bumpier corners and not working well just after turn-in or when the brakes were released. A best time of 77.34sec was recorded after three flying laps.

Already we could see the GTI was working better than stock, but we couldn't say how much of that was attributed to the engine and brakes. However, Mark Hotchkis felt he could make improvements to the chassis balance. He suggested that reducing the rear tire pressure at this point would've yielded good results through the slower section and provided less suspension through the sidewall of the tires. We were more interested in what the actual suspension components were doing at this point, so instead we opted to remove the 32mm rear sway bar and swap it for H-Sport's 28mm bar. It was mounted on the soft setting by using the last of the three holes in the bar (furthest from the middle of the bar itself). The front shocks were also adjusted to full hard. Mark's intention was to calm the rear in the tighter section of the course.

In this configuration, a best time of 77.67sec was recorded. This was slower than before since the rear seemed to follow the bumpy surface better with the new sway bar but turn-in bite wasn't as crisp. On the high-speed sections, the new bar and shock adjustment made little difference to the car's overall stability.

A best time of 76.22sec was achieved, proving we had better turn-in and traction. It's interesting that we couldn't achieve this result with a higher-rate rear bar through the slower, bumpy corners, even though that bar felt great in the high-speed turns. It's possible we could have achieved the same results with the bigger bar if we had more time. We also wanted to try removing the rear sway bar altogether to get some really extreme results, but sadly the car encountered drivetrain problems after being pushed so hard all day. The Michelin tires were also past their best, so we decided to end it there.

The next experiment was to back off the front shocks and restore them to five clicks from full hard, as they were before. This seemed to work much better with the lighter, narrower rear sway bar over the slow, bumpy sections, and it still had no real negative effect in the high-speed areas. The best time was 76.53sec in this configuration, which showed a real improvement in lap times and that we were now headed in the right direction.

Next, Mark decided to try full hard on the rear shocks simply because they were nearly there anyway (previously six clicks from hard). With the narrower rear bar, he felt we could get away with increased bump and rebound from the dampers without hurting the ride over the slow, uneven areas of the track.

Again this worked well, and you could feel more support and resistance from the outside rear tire through the corners. This also seemed to help front traction when accelerating out of corners.