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 Post subject: Re: Level 2 carburators?
PostPosted: Thu Aug 06, 2020 2:46 pm 
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Ok. Then level 1 isn’t allowed the modifications done. If both rule sets are the same for carbs now then both are allowed the same thing.

And why would Induction be included in the drive train section.


Something changed. When did it change and why

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 Post subject: Re: Level 2 carburators?
PostPosted: Thu Aug 06, 2020 2:55 pm 
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Ron Bartell wrote:
Whaaaaaaatttt? When did level 2 carbs get to be modified.....at all? Level 1 carbs were always allowed to be heavily modified with the only restriction being that they started out as a stock part and met the size restriction at the butterfly. Level 2 carbs had to be bone stock, period. I remember discussions about whether the dashpot parts had to be run even though they had no effect without running the oil in the chamber.

I agree with Kevin - if it doesn't say you can do it you can't in level 2.

Refer to CGR from Sept 2019. all this section is in red at that time, which means it was "approved" around Aug 2019 for inclusion in Sept 2019 GCR. maybe so all the L2 cars running around with modded carbs wouldn't be caught in the tech shed at runoffs?

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 Post subject: Re: Level 2 carburators?
PostPosted: Sat Aug 08, 2020 4:31 pm 
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Matt93SE wrote:
Refer to CGR from Sept 2019. all this section is in red at that time, which means it was "approved" around Aug 2019 for inclusion in Sept 2019 GCR. maybe so all the L2 cars running around with modded carbs wouldn't be caught in the tech shed at runoffs?

September 2019 was too late for me to make any changes in time for the Runoffs, but I raced my last race with a bone stock carburetor against others who had modified there carbs or FI systems in advance of a rule change, and I got beaten down the straight by those other cars. Real nice.

I don't remember any discussion or "out for member input" on this one. Maybe I missed it. Seems like it got snuck in to protect some that took an illegal lead off base. Level 2 carbs were supposed to be stock.

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 Post subject: Re: Level 2 carburators?
PostPosted: Sat Aug 08, 2020 7:26 pm 
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This seems like a mess to me. Obvious drafting error IMO.

First re "Drivetrain" - the GCR Technical Glossary defines drivetrain as

Quote:
Those rotating components in a car that convey the driving power from the engine flywheel to
the ground and the housings containing these parts. This is inclusive of the clutch, transmission, driveshaft,
differential, halfshafts/axles or any systems providing such functionality.


Yet under 9.1.5.E "Authorized Modifications" Section 1 is plainly headed "Drive Train Level 1" and includes all engine and induction components, in addition to the clutch, transmission, driveshaft etc as defined in the glossary. Thus the rules section is at odds with the glossary.

This leads to confusion as to whether 9.1.5.E.1.a.1 & 3 (which are rather sweeping allowances to modify, add thermal coatings, etc) apply to just the drivetrain as defined in the glossary or to all systems covered under 9.1.5.E.1 which again includes engine and induction. The layout of the rules would imply the latter but this is certainly at odds with the glossary.

Also note that if 9.1.5.E.1.a.1 & 3 apply only to the drivetrain as defined in the glossary, then thermal barrier coatings are legal in the transmission but not the engine. Which seems very odd.

If 9.1.5.E.a.1 does not apply to engine and induction, Level 1 and Level 2 carbs need to be nearly bone stock. If it DOES apply, Level 1 and Level 2 carbs can be modded within the rules exclusions.

Either way, Level 1 FI throttle bodies can be ported and polished subject to restrictions, as this is called out in 9.1.5.E.1.b.4. Level 2 FI throttle bodies might be able to be modified within limits IF 9.1.5.E.1.a.1 applies to induction.

I think that there is a severe drafting error here, but I'm not 100% sure what the rules intentions actually are.

If you don't agree with me at all, and fall back on the technical glossary definition of drivetrain, then you are saying (IMO) that:

1. Level 1 carbs suddenly became almost bone stock last year, but FI throttle bodies remained ported. Why?

and

2. Thermal barrier coatings are legal in transmissions but not engines. Why?

Edit - found something else. The Level 1 cylinder head rule cites:

Quote:
Porting, polishing, and machining within the limits of Production Car Rule E.1.a.1 E.1.a.2., is
permitted.


If those rules apply only to transmission etc (ie drivetrain per glossary) why are they being cited wrt cylinder heads?


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 Post subject: Re: Level 2 carburators?
PostPosted: Sun Aug 09, 2020 8:30 am 
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Matt93SE wrote:
Refer to CGR from Sept 2019. all this section is in red at that time, which means it was "approved" around Aug 2019 for inclusion in Sept 2019 GCR. maybe so all the L2 cars running around with modded carbs wouldn't be caught in the tech shed at runoffs?


I haven't been following the nuances of L1/L2 carburetors but I am surprised to see a change like this made in September, just before the Runoffs. There used to be an understanding between the BoD and the CRB that there would not be any rule changes after 1 June (sometimes slipped to 1 July). Competition adjustments (weight and plate) could be applied as needed. If this GCR change Matt referenced above created the issue, it is a deviation from previous policy.


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 Post subject: Re: Level 2 carburators?
PostPosted: Mon Aug 10, 2020 6:20 am 
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I'm with Ron. My understanding was that Level 2 carbs were always supposed to be bone stock. Are people really running around with modified carbs in L2?

Hoping this was just an oversight, but either way, the CRB needs to clarify.

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 Post subject: Re: Level 2 carburators?
PostPosted: Mon Aug 10, 2020 6:32 am 
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Sept 2019 Fastrack includes the changes under Letters 27300 and 27301 (Prod Committee) Clarification of Carb Rules. Also note the header of the bottom line in the technical bulletin into below..

Link for reference- Sept 2019 Fastrack starts on page 276 of the 2019 archive file:
https://www.scca.com/downloads/49142-19 ... 8/download

[quote=Sept 2019 Fastrack]
TECHNICAL BULLETIN
DATE: August 20, 2019
NUMBER: TB 19-09
FROM: Club Racing Board
TO: Competitors, Stewards, and Scrutineers
SUBJECT: Errors and Omissions, Competition Adjustments, Clarifications, and Classifications
All changes are effective 8/31/2019 unless otherwise noted.
[/quote]

So how it got to this point was obviously prior to Aug 2019. discussion ensued and "letters were written by the Prod Committee" :ask: and THEN the rules were clarified.

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 Post subject: Re: Level 2 carburators?
PostPosted: Mon Aug 10, 2020 11:55 am 
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Stiner0931 wrote:
I'm with Ron. My understanding was that Level 2 carbs were always supposed to be bone stock. Are people really running around with modified carbs in L2?

Hoping this was just an oversight, but either way, the CRB needs to clarify.


As the rulebook stands today, carb prep rules are the same in L1 and L2. You can make arguments (see my post above) as to exactly what those rules allow, but they are the same for both categories. As of today, if modded carbs are legal in L1 they are also legal in L2. If they are illegal in L2, they are also illegal in L1.

About the only thing that is really clear is that L1 Fuel Injection throttle bodies can be ported. L2 throttle bodies are subject to the same and/or interpretation as L1/L2 carbs.

As I argue above, the intent of the rules is unclear but they are almost indisputably screwed up. I'm not racing this year - sadly - but if I was I'd want this cleared up ASAP. In the meanwhile I won't be porting my L2 FI throttle body as I'd bet that the end result will be as in early 2019. L1 cars with modded carbs / FI throttle bodies and L2 bone stock.

As an aside, how did this not blow up at Runoffs last year? Did everyone just assume that the old rules were still in place?


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 Post subject: Re: Level 2 carburators?
PostPosted: Mon Aug 10, 2020 12:25 pm 
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Al Seim wrote:

As an aside, how did this not blow up at Runoffs last year? Did everyone just assume that the old rules were still in place?


Probably didn't even bother to check because the changes went into effect an unprecedented 5 weeks prior to the Runoffs...

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 Post subject: Re: Level 2 carburators?
PostPosted: Mon Aug 10, 2020 1:13 pm 
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The basic flaw underlying all this has been festering for a while. See the last few posts of this thread:

viewtopic.php?f=7&t=18518&start=40


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