Good question, Mr. Kramer!
First off, those who suggested they were legal "back in the day" are
partially correct. For FIA International events (Sebring, Daytona, 1000KM
Sports Car events, IMSA), there was the allowance in the FIA rules to
utilize threaded collars for adjustable ride height, following Sports Racer
and Formula Car practice. The Trans Am rules for Under 2 Liter sedans were
based on the FIA Sedan rules that permitted this "coil-over" shock absorber
in the 2.5 Challenge in 1972, as well. However...
Section 3 of the 1972 SCCA General Competition Regulations (GCR), which
governs Production Car Specifications (PCS), which is what, I believe, CVAR,
SOVREN, SVRA and others look to as the definitive specification for those
cars eligible for Production Car racing (Datsun 240Z = C Production as of
4/72), states clearly that it is not permitted to change:
"...their system and points of operation."
You also point out correctly that:
"...under section 9 "Springs or torsion bars of any kind may be replaced by
any others of unrestricted origin, but without changing the number supplied
by the manufacturer and on the condition that they can be fitted without
alterations to the original supports and points of attachments."
The purpose of this clarification and delineation (as explained to me by
several members of the SCCA Competition Board at the time) was to make
certain people did not alter suspension pick-up points to improve geometry
on Production cars (although this did occur and was permitted by that point
in the Sedan rules).
There are those of us who remember a decade ago the tremendous row over
allowing coil-overs first, then ADJUSTABLE SPRING SEATS in Street Prepared
(SCCA Solo II, or Autocross) and SCCA Improved Touring (originally this was
NOT permitted). Many people were replacing springs and cutting off the
excess spring perch or using the original spring perch as a platform to
anchor the base of the spring in SP and IT, but the clarification from the
Comp Board ultimately allowed adjustable perches.
In my opinion, your club may vary, the rule is clear, no adjustable spring
perches were permitted for Production class cars as of 1972 (actually 4/73,
as well).
Practically, as long as the control arm pick-up point and length have not
been altered on a strut type suspension, the "coil over" adjustable perch
isn't going to do anything except make it easier to corner weight the car.
What do you do? Outlaw camber plates as well? It's been a non-issue, as far
as I can see, for some time...
-Peter Krause
|