GTB/ZR-1

This is direct from the rulebook reagarding cams in Grp II:


In section: 2.7.3.12 ENGINE, ENGINE COMPONENTS AND ACCESSORIES:

22. CAMSHAFT--Any camshaft that meets General Motors specifications for lift and duration for Class.

Okay, what in the world does that mean?
Would a GM 'Hotcam' qualify? The way I read it is.... I guess so (?)

I'm just starting to get involved w/ their events, and I was looking through the allowed mods in Grp II where my car is classed (it's prepped an an ASP SCCA car).
I was toying w/ the idea of putting a different cam in my car while I pine away for the C6 Z, to help appease my desire for more hp

Any experience out there trying to take advantage of this rule?

Also, 2 rules that I think are a bit restrictive for Grp II:
--Drilled rotors & aftermarket shifters are not allowed--why

BTW, thanks Chris (69autoXer) for getting me a copy of the rules

69autoXr

George, reread the Group 2 rule about aftermarket shifters. I know my copy isn't different from yours

Drilled rotors has been a big controversy for Group 2, many think they should be allowed, while others refute that there's no performance benefit so why should they be allowed? I expect this may change with the next update but who knows with NCCC.

As for the HOt Cam, I don't think so. It says "...lift and duration for class...", well the Hot Cam never actually came installed from the factory, it was only available in aftermarket sales.

AU N EGL

Really ?? Here are the GM cams that I have listed for the LS1/6 motor

LS-6 207/217 525/525 116
Gen3 Hot cam 219/228 525/525 112
GMPP ASA 226/236 525/525 110
GM- Grand am cup 239/251 570/570 106
Lingenfelter GT2-3 207/220 573/580 118.5
GT1-1 229/242 631/631 114

GTB/ZR-1

Listed where? Are they all allowed?

GTB/ZR-1

Oops, you're right Chris-my bad.

Another thing, an aluminum flywheel not allowed? I think they s/b in Grp II--it's not a huge mod advantage by any stretch IMO...

AUTO_X_AL

I think the light flywheel is a big advantage but I do recall something about the cam having to meet factory LIFT specs. Do not quote me on this but I believe the lift has to match but I think the duration is open. I could be totally wrong but I do remember a couple of conversations pertaining to this very topic on the legality of non factory cam shafts. If I am wrong I apologize in advance.

AU N EGL

Those are cams made by GMPP. Does not mean they are legal for NCCC.

69autoXr

No aluminum flywheels. The nice thing about 2A/B is the L88 lightweight flywheel

The cam rule is quoted above-lift and duration. I think the intenion of that rule is to allow cams manufactured in the aftermarket as copies of the factory cams which may be discontinued by GM. Then again I think there are things that can be done with the ramp opening/closing rates in a custom ground cam yet still meet the lift and duration specs of a factory cam. Someone who knows more about camshafts may be able to shed more light on the subject.

GTB/ZR-1

Understood, but the verbage & especially the word class is very vague--unless class is defined elsewhere in more specific terms, which I haven't found yet...

Heck, if Smokey Yunick saw that entry, I'm sure he'd be all over it!

69autoXr

Group 2 Classes:
CL=62-older
A/B=63-82 hi perf small blocks and big blocks
C/D=63-82 low perf small blocks
E=84-91 CF and L98
G=92-96 LT1 & LT4, E cars with LT1/4 with correct trans for engine
F=ZR-1
H=C5 non-Z
J=C5 Z and H cars with LS6/M12?(Z06 trans-cant' remember if it's 6 or 12)
K=C6 non Z
M=C6 Z

Bill Dearborn

This means the cam for a Group 2H car would have to meet the lift and duration requirements of an LS1 engine delivered in a C5 from 1997 through 2004. It does not mean the cam has to be a factory cam.

If you read the Group III section you find that drilled rotors are allowed but not recommended. The idea was to discourage drilled rotors in Group II since the major consensus is they do not enhance performance and are more prone to cracking during high speed events which these rules apply to also. If I remember the discussions correctly they were permitted in Group III since a large number of Group III cars already had drilled rotors.
Bill