Shocks must be adjusted for each track

CONCORD, N.C. -- When anyone asks how Mike Cluka's day went at work, he can answer with one word --- shocking.

Cluka serves as the shock specialist for Johnny Benson and the No. 10 Valvoline Pontiac team in the NASCAR Winston Cup Series. With a decade of experience to his credit, Cluka said that each track brings a surprise every time the team returns for a race.

"You try to use the same shock set-up you had before," Cluka said. "But, the temperatures or track surface might be different than the last time we were here. So, all you can do is be prepared for whatever comes up by having four or five different sets to choose from.

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"The main job of the shock is to keep the car from hopping around once it comes off the corner. You want to get a nice, fluid motion that keeps the car on the track and not beat the tire up too much.

"If you ever watch old races, you'll see how those cars bounced around so much. Now, shock packages have become very important so that doesn't happen."

At the MBV Motorsports shop, Cluka has 120 shocks to choose from when making his race selections. One group is referred to as "base valve" shocks, which is more of a race shock that requires a different body than a standard qualifying shock. Those allow the team to run more gas pressure during the race.

The rest of them are standard body shocks used for superspeedways and for qualifying at the rest of the tracks. A factor called "bleed difference" allows how fast/slow the shaft comes out of the shock.

For a track like Martinsville, the team needs to have a shock that allows a lot of play in the piston. With all the braking that takes place at that short track, it's important that Benson can turn the wheel when he exits a turn.

Darlington Raceway is a good example when it comes to shocks. The bleed difference there is a little less, but the shock still needs to be factored into allow the car to go over the bumps and not skip over them.

"With aeropush being such a problem these days, we try to use our shocks to fight that," Cluka said. "With all the attitudes and angles of the car, we try to take that away or hold it in place with shocks.

Penske Shocks and Olin Shocks are the primary providers of shocks to the NASCAR teams. They make every component of the shocks that the team purchases.

"Shocks are can be completely rebuilt and are adjustable," Cluka said. "So, you can change the shim stack, one of 12 different pistons in Penske and eight in the Olins. You can use the jets and needles, too.

"The jet is what makes the shock adjustable by opening the clicker on the bottom of the shock. That adjusts the compression or rebound by opening or closing it."

"When a spring goes into compression, you have to have something slowing it down when it comes back out."