If you have the time to read:
This thread has produced a lot of real reasons why added or modified front
bars have been utilized on many types of cars.
However, my guess is that the origin of the SCCA allowance for "free" front
bars in stock classes probably developed out of the practical necesity of
attracting the greatest number of the, then, "existing" autocross
competitors/cars to join in the fun with the initial, fledgling, SCCA Solo
II program.
Not going back to the beginning (whenever that was) but going back to the
early sixties there was quite a bit of, what we now generally call
autocross, activity in many places around the country.
I'm speaking mostly from my experience in Northern California, where the
Northern California Sports Car Council (NCSCC, pronounced nicsic) maintained
the dominant autocross series. In those days each "sanctioned" NCSCC event
was put on and run, including manning all the work assignments, by
individual "sports car" clubs. In the SF bay area one of those clubs,
belonging to NCSCC and staging sanctioned events, was the SFR SCCA.
In those early days the NCSCC "allowances" in stock classes were not well
controlled and, to say the least, were excessive. The only other, limited,
first-hand knowledge I have of other locales, in those years, was with (what
I think was called) the Souther California Council of Sports Car Clubs. They
had similarly liberal stock class "allowances". Here's an example of the
type of car that could be "legally" run in a NCSCC stock class in 1967.
Since I'd been running Corvairs since 1962, I had first hand knowledge of
the detail "allowed" modifications included on some of the "stock" '65 and
later Corvairs during the '67 season. I say "allowed" because there was very
little enforcement/interpretation of what was legal and few, if any,
competitors were dis-qualified or denied "champioship" points when running
with some or all of the, below, modifications. The following is a "short"
list of these, so-called, "allowances".
1. Shortened springs all around to lower the car, reduce roll and
increase the, effective, spring rate. This included running the heavier,
and shortened, convertible HD springs on coupes.
2. Wider wheels of any offset up to 50% wider than stock, rounded to the
next half inch. (in the Corvair case this allowed 8.5" wide rims compared to
the stock 5.5" width.
3. Any tire was allowed. A popular tire for the Corvair was a gumball
recapped 10.50"x 24"x13" firestone oval-track pure race tire.
4. Quick steering arms to reduce the number of steering wheel turns,
lock-to-lock.(although on '66s you could get a quick steering box installed
by the factory)
5. Quick shift mechanisms to reduce the shift lever travel.
6. Any steering wheel.
7. Any driver;s seat and no back seat required.
8. Any brake shoes, like Camaro/BOP intermediate rear GM metalic for the
front and Olds Vista Cruiser station wagon GM metalic rears for the rear.
9. Substituting normally aspirated high compression, big port, big
valve, 4 carb heads, exhaust manifolds and fabricated exhaust plumbing on
Turbo-charged Corsa motors in place of the stock turbo, small valve, low
compression heads.
10. Any exhaust manifolds/headers, with mufflers optional.
11. Modifications to the stock turbo side draft carbureator to
minimize/eliminate flooding and starving on turns.
12. larger diameter pully on the fan to save significant HP by reducing
the theoretical fan RPM from 9600 RPM to 7200 RPM at a crankshaft speed of
6000 RPM.
13. Special spring loaded mechanisms to reduce/eliminate
breaking/throwing fan belts.
14. On turbo motors, water injection to reduce/eliminate detonation
caused by higher compression heads, thermally wrapped exhaust pipes, and the
eliminated pressure retard mechanism (on a stock turbo motor, this mechanism
was located on the distributor in the same location as a vacuum advance
mechanism used on normally aspirated motors but, retarded the spark relative
to the amount of manifold boost it sensed by as much as 18 degrees at
approximately 10 PSI boost. Remember, if you can, we were also running 100
octane Standard Supreme, leaded, pump gas.
15. Any plugs, plug wires, distributor caps/rotors.
16. No air cleaner(s) required.
I said "short" "list" because I've probably forgotten some, or many, of the
"minor" but, common, modifications that had crept into stock classes in
those days but, are not allowed in today's SCCA stock classes.
Now, to be fair to NCSCC and the past, the above example of how far out of
hand the "stock" classes had gotten by '67 came about in a very short few
years. As recently as '64 the exagerated modifications such as wide wheels,
substituted springs and different heads weren't being used in the stock
class that my Corvairs were in. For the '68 season, NCSCC established a
class structure and rules that significantly limited "modifications" allowed
in a newly defined set of "stock" classes.
Oh, but back to the subject. I didn't forget stabilizer bars, which were
also "free" in NCSCC stock classes.
Although, I don't have much knowledge of the suspension design details of
the many sports cars and sedans running in the sixties,(there were a lot of
50s and 60s sports cars running) one thing for sure is that stabalizer bars,
as we know them today, were pretty new at the time. I added an after-market
bar to my "stock" '60 Corvair in '62 (no factory-installed bars showed up
until '62 when the HD suspension option included a front bar and it wasn't
until '64 that all Corvairs came equiped with a front bar).
So my guess is that in many areas around the country, in an effort to
"equalize" performance of various cars/classes, and as tires were getting
better resulting in greater cornering "bite", it was probably obvious that
many, otherwise stock, cars, not factory equiped with front stabalizer bars,
were at a significant performance, not to mention safety, dis-advantage.
Also remember, limited slips weren't all that common and excessive body roll
lifted inside rear wheels. I think these reasons are what probably led to
the acceptance of added front bars, in stock classes, by some, or many, of
the numerous sanctioning bodies.
Therefore, and again this is just my guess, by the time SCCA started
formulating, what we now know as, the SOLO II program, in the early
seventies, there were probably a lot of cars running in locally sanctioned
"stock' classes, all over the country, with, among other modifications,
added or non-stock front stabalizer bars.
Just go back a few years into the early sixties and late fifties and you'll
find only a handfull of american cars equiped with front stabalizer bars,
And it wasn't until the Pontiac GTO, in '64, or the Olds 442, that (I think)
we first saw any american cars with factory installed rear stabalizer bars.
So, since the front bar generally, reduced body roll, therefore reducing the
tendancy for vehicle roll-overs, I think, whenever the SCCA rule was
formulated making front bars, essentially, free, it was done as an inclusive
move to, safely, intice the greatest number of "stock" competitors into
competing in the various local SCCA sanctioned events.
So why not "free" rear bars? The incentive is not the same. A rear bar, at
least on front engined cars, has much less influence in the control of body
roll, therefore the value of rear bars in improving roll-over safety is
significantly less. Remember, when SCCA was formulating the SOLO II program
most competing cars were front engine/rear drive or rear engine/rear drive.
There were only a few front engine/front drive and "exotic" mid-engine/rear
drive vehicles. So for the majority of potential stock class "customers",
the only stabalizer bars being used were front bars.
Like I've said several time in this long discourse, this is just my guess!
Don
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