December Fastrack Prelims

[Tim White]

I see they have updated the January 2021 GCR, now the tire rule only restricts the A7 but they are valid until 6/15. They cannot get this right, all they had to do was keep the list but add the 6/15/2021 start date.

I still don't get the 13" rotor thing. I think there should be 50lbs added for running a rotor greater than 12.2". There are so many options at 12.2", there was never a reason to cut down a 13" rotor.

[PamRichardson]

Tim --

I believe a lot of the tires on the list are no longer available.

Pam

[PbFoot]

The following was posted on 1-5-21

3. #29826 (American Sedan Committee) Introduction of restrictor plate for Full
Preparation engines
In AS, GCR Section 9.1.6.D.1.c.1.c., add the following:
"Effective March 1, 2021, all cars shall fit a 1/8 inch flat plate, sharp edge orifice, 4 hole
restrictor between the Carburetor and insulator, All air entering the intake must pass
through the restrictor plate. The center of the holes of the restrictor plate must be aligned
within 3.0mm of the centers of the carburetor throttle plate holes. The max diameter of
the holes is TBD. unless specified in the individual car’s specification line. An additional
base gasket, as described in section 9.1.6.D.1.c.1.a may be used."
In AS, GCR Section 9.1.6.D.1.f.1.e., add the following:
"Engine RPM limiters must be installed on all vehicles. Maximum engine RPM is 7600.
Individual vehicle/engine limits may be adjusted and would be specified on vehicle
specification lines. RPM limits must be demonstrated by the competitor upon request of
SCCA official."

[Tim White]

I created a poll in the poll section just to get a temperature. If people favor this I guess I'll get inline or something. Based on the letters I saw it seemed to be 8 against and 1 for. I don't see how something can go forward when there seems to be such opposition.

[jimwheeler]

I think the restrictor deal has far more negative votes than positive. If it goes into effect, we all have to run out and have restrictors built, with holes that have no dimensions.

[Ted Johnson]

Jim...

Many moons ago when you were an adhoc member you posted these proposals in 06. These proposals back then before the eddy heads were very well done and forward thinking. Your proposal for 2009 included a power to weight ratio and restrictors.

If the small valve edelbrock head rpm is no longer available, and the 2.02 valve rpm head is available, I'd say your 2009 proposal is spot on for regulating the hole size of the up and coming restrictors given your proposed power to weight ratio. Not to mention the inclusion of the "new" to that era gen 3 chevy. With power to weight ratio and restrictor, these are great ideas. Kudos.

So I'm not understanding your reluctance to restrictors when you as an ad hoc member proposed them?

Kudos for these 2009 proposals so many racers were on board with back in the day. Maybe push the crb to make these ideas you proposed back then the new standard?

PROPOSED RULE MODIFICATIONS FOR 2009


Introduce Alternative cylinder heads:

1. Any cast iron cylinder head, modified or unmodified, meeting OEM critical dimensions TBD. (ie. No splayed valves, shaft mounted rockers, etc.). Production or after market (all other rules supersede, except valve diameter.) may be used with a designated restrictor plate, with dimensions TBD. Goal is to achieve 8.5 lbs./hp (3280 lbs/385 hp.)
2. Appropriate Edelbrock Performer RPM manifold must be used.
3. Current Holley 600 CFM carburetor as currently designated.
4. Restrictor plate will be positioned between intake manifold and insulator spacer.
5. Maximum lift, at zero lash, remains .500 inches.
6. Maximum lifter bore remains at .8740 inches.
7. Valve diameters to be limited (ie. intake 2.02 inches/exhaust 1.60 inches)

Introduce Chevrolet Gen III engines

1. Any Generation III cast iron block with a maximum bore diameter of 4.040 inches with OEM critical dimensions.
2. Any crankshaft may be used with a minimum weight of 42 pounds, and production Gen III bearing diameters as currently designated.
3. Any ferrous rod (no titanium) may be used with a maximum of 6.1 inches center to center dimension.
4. Any piston may be used, including domed pistons. (Maximum compression ratio of 10.3:1 remains)
5. Maximum swept displacement is 5.11 liters. (Equivalent to today's maximum displacement)
6. Any cast iron cylinder head, modified or unmodified, meeting OEM Gen III critical dimensions to be determined, (ie. no splayed valves, shaft mounted rockers, etc.) production, or after market, (all other rules supersede, except valve diameter) may be used with a designated restrictor plate, with dimensions to be determined. Goal is to achieve 8.5 lbs./hp (3280 lbs./385 hp).
7. Appropriate Edelbrock Performer RPM manifold must be used.
8. Holly 600 CFM carburetor, as currently designated, must be used.
9. Restrictor plate will be positioned between intake manifold and insulator spacer.
10. Firing order must be 1-8-7-2-6-5-4-3
11. Maximum lift, at zero lash, remains .500 inches.
12. Maximum lifter bore remains at .8740 inches.
13. Crank triggered ignition may be used with Gen III engines.
14. All other existing rules still apply.

There will follow a post including the feedback from the CRB with their concerns and a note to the membership, at large, from John Blanchard, the AdHoc committee Chairman. (I had to stop typing for a meeting)

Jim Wheeler, for the Adhoc committee.