Shocks at the Indy 500
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Engineer Jeff Braun talks to driver Ronnie Johncox as Eibach
shock technician Cooper King listens.
Eibach springs and dampers coming off a Riley & Scott
chassis. The team gave up on the R&S chassis as did the other
teams that tried to run them. The consensus is the R&S chassis
didn't incorporate the same gains from last year as Dallara and
G-Force. The engines lost about 70 hp going from 4.0 to 3.5 liters.
That cost the 1999 Dallara and G-Force cars about 10 mph, from
227 to 217. Off-season wind tunnel development put the 2000 chassis
back to 223. But not the R&S. Lift/Drag is the whole deal.
The Eibach damper is not a revolutionary design. It's an external
reservoir, pressurized, double-adjustable monotube design. But
its small diameter combined with smaller diameter springs could
have a packaging benefit. The modular design is well thought
out and the shock just looks good. The internal components emphasize
low weight and low friction as well as adjustment repeatability.
The driver, Ronnie Johncox, said he could feel the difference.
He told me the car moved around less and felt more predictable
so felt more comfortable closer to the outside wall entering
and exiting the turns.
Here's a front suspension using one Hypercoil spring and one
Eibach spring (the red one) with Ohlins TT-44 dampers. These
are 3-way adjustable but 4-way is available.
Koni 2812 dampers are mounted on this car. Truesports, the
U.S. distributor for Koni has modified these dampers for less
weight. It looked to me like about half the cars in the garage
at Indy used Konis, a third used Ohlins TT-44s and the rest Penskes.
This is in contrast to the CART paddock where you'll see TT-44s
on all the cars except Newman-Haas who use a proprietary Ohlins
system and Rahal who make their own dampers similar to Penske
The damper is arguably the most critical component on a racecar.
A team has to use the tires available and the driver is hired
for all kinds of weird reasons. The damper is the only adjustable
component in the amazingly important triangle of driver, tires,