Open Road Racing
our Porsche 928 - Part 2
by Susan Kirby & Marc Thomas of DEVEK
A good example is when we were first investigating competitive suspension kits and used
a progressive spring on the front and moved the old front springs to the rear. Once
underway, we entered the first high-speed sweeper and felt the 928 undergo an unusual roll
transition with a springy rear end. We realised that progressive front springs made for
unpredictable "roll" when the 928s cornering loads increased beyond normal
around town/highway driving. Also, rear to front spring ratio was grossly out of
proportion. A quick discussion with a few suspension experts, modified front and rear
spring rates, and a switch to a standard non-progressive spring eliminated the problems.
We have been using that setup on all our DEVEK
coilover kits with great success.
Aerodynamic modifications are also necessary to improve stability and reduce the
coefficient of drag at speeds over 170mph. The 928 gets some special tape treatment, with
the entire front end of the car being masked over. Side mirrors are removed, and a special
front air dam installed to prevent air from going underneath the car. We also employ
ground effects to minimise drag and maximise downforce. We have also received factory
assistance with regards to high-speed aerodynamic stability for the type 928.
As we became more & more comfortable with open road racing, the obvious desire to
go faster and faster developed as well. Our 928s engine went from 5.0 litres to 6.0
litres, then to its current 6.5 litres of displacement, producing 500 hp and 580 lb-ft or
torque at the crank. The most amazing feature of our "928 test mule" is that
its engine now has over 38,000 miles, has exceeded 200 mph over half a dozen times,
and is driven every day!
The highest class of Open Road Racing is the Unlimited Class, which is generally
reserved for full race cars, some with top speeds in excess of 240 mph! In order for us to
compete at that level, we had to make some major modifications to our 928, which we
completed in time for the inaugural Big Bend Open Road Race in Ft. Stockton Texas in July,
1998. The addition of a full roll cage, onboard fire system and competition fuel cell
allowed us to enter this class for the first time. An added benefit of the Big Bend Open
Road Race is that it was a two-way "down & back" race, and we were able to
switch driver/navigator between stages. With a finish-line radar speed of 205 miles per
hour, we took second place in the highly regarded Unlimited division, competing against
many purebred race cars! Not only were we the fastest street legal entrant and the fastest
car ever to drive to and from any event, but we posted the fastest finish line radar speed
of the event - not too bad for a street car!
This is one aspect of these events that we are particularly proud of - we have driven
our car to and from every event. We dont even own a trailer. With over 140,000 miles
on the chassis, we love the fact that we have a car comfortable enough to drive 3,000
miles round trip and post speeds well over 200 mph at these events! Frequently we will
drive "back to back" weekends, going from an open road event in Nevada one
weekend, then running competitively at Laguna Seca the next weekend.
We are excited every time a new 928 owner comes out for an open road race and would
like to see more 928 participants in future events. Someone needs to keep those pesky
Mustangs, Corvettes and Vipers in line! If you would like to find out more about open road
racing or preparing your 928 for other racing events, please give us a call at DEVEK (650-592-5287) or contact Classic Auto Racing Society
Be Safe and Be Fast, in that order, please!
- Susan Kirby & Marc Thomas of DEVEK