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 Post subject: Re: Level 2 carburators?
PostPosted: Mon Aug 10, 2020 2:32 pm 
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Aaron Johnson wrote:
fuel injection for both L1 and L2 are very specific that nothing can be done to the throttle body
This is not true. There are 8 other paragraphs that define what you can do to prep level 1 carbs intake manifolds and throttle bodies.

I have re-read the rules for prep level 2 and I don't see anything in the Fastrack News that allows modifications to the carbs or throttle bodies other than replacing metering devices, jets, etc. It reads:

Carburetor jets, jet needles, metering rods and needle valves are unrestricted. Choke mechanisms, plates, rods, and actuating cables, wires, or hoses can be removed

The wording that mentions porting and polishing intake manifolds and carbs is not there in the revised rules. They did leave out the words:

The stock or permitted alternate carburetor must not be modified.

I think that this phrase needs to be put back in, but if it doesn't say you can do it.......

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 Post subject: Re: Level 2 carburators?
PostPosted: Mon Aug 10, 2020 3:41 pm 
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Ron Bartell wrote:
I think that this phrase needs to be put back in, but if it doesn't say you can do it.......


Which also applies equally to L1. So if 9.1.5.E.1.a.1 really does NOT apply to the engine (which I believe is a drafting error), there's nothing in the current rules allowing airflow enhancing mods to L1 carbs. Which I agree is a big (probably accidental?) change vs the past, one that would for sure impact balance of performance.

This whole thing is screwed up and needs to be fixed.


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 Post subject: Re: Level 2 carburators?
PostPosted: Mon Aug 10, 2020 6:32 pm 
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You’re right Ron and now that I read that l1 throttle body rule it seems like it used to say that type of wording for carbs. I can remember the thinning of shafts language and butterflies being brazes etc.


So two ways to look at this debacle. L1 can’t be modified because it’s not drive train and it doesn’t say you can do stuff to improve it

Or

You can mod the crap out of l2 carbs because they are in the drivetrain section and chemical and mechanical modifications are allowed

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 Post subject: Re: Level 2 carburators?
PostPosted: Tue Aug 11, 2020 3:09 am 
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iesi
Al Seim wrote:
This whole thing is screwed up and needs to be fixed.
I agree that it is screwed up and needs to be fixed. The wording for fuel injection for prep level 1 has wording that allows modification to the throttle bodies and butterflies, so I am sure that there is intention to allow the same thing for carbs in level 1. There are some words that don't make sense though, like:

The inside dimensions of the throttle body casting/housing and all dimensions of
the throttle butterfly must remain stock. The throttle body can be ported and polished.


That doesn't make sense and seems to be contradictory.

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 Post subject: Re: Level 2 carburators?
PostPosted: Tue Aug 11, 2020 4:35 am 
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Yes. And the part about L2 carbs: "The stock or permitted alternate carburetor must not be modified" needs to be put back in as well.

Hopefully this can get cleaned up before the Runoffs. They made changes on 9/1 before, so I don't see why it can't happen again.

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 Post subject: Re: Level 2 carburators?
PostPosted: Tue Aug 11, 2020 6:29 am 
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Let me summarize what I think has gone wrong. In my view:

9.1.5.E.1 and 9.1.5.E.2 Should both read "Power Train" or "Drive Train Plus Engine", not "Drive Train". IE it encompasses everything from induction to drive axles.

(If you look at the subheadings in this section, the majority of them are NOT "Drive Train", ie b. Induction c. Emission systems d. Cylinder Head f. Camshaft g. Block h. Pistons i. Crankshaft j. Oiling k. Electrical l. Exhaust etc. This pretty much proves that the heading "Drive Train" is a typo.)

Similarly, 9.1.5.E.1.a should read "Power Train" in the heading and where "drive train" occurs in the paragraphs.

This then gives a fairly broad ability to modify, coat but not add on to various parts of the power train. This allows fairly extensive modifications which are then circumscribed in detail by the subheadings below, more so in L2 than in L1. This gave the ability to, for instance, modify (within bounds) L1 carbs and FI throttle bodies, but was circumscribed for L2 carbs and throttle bodies by restrictive language.

Sometime in the past two years, someone astutely spotted "drive train" in 9.1.5.E.1.a and realized that this did not - as worded - apply to carbs etc. But rather than changing "drive train" to "power train", the subheading language was changed in several areas. And now it is all screwed up.

So to repeat, what I think the rules intended re carbs and TBs was:

L1:

9.1.5.E.1 should say Powertrain.

9.1.5.E.1.a should refer to Powertrain, opening up (among many other things) internal airflow mods in carbs and TBs, subject to limitations under 9.1.5.E.1.b Induction. 9.1.5.E.1.b should NOT forbid "porting and polishing" or otherwise try to mandate a bone stock airflow passage.

This puts L1 induction back to where it has been for decades.

L2:

9.1.5.E.2 should say Powertrain.

9.1.5.E.2.a should refer to Powertrain, opening up detail parts mods just as in L1, except subject to tighter restrictions under the subsequent subsections. And 9.1.5.E.2.b SHOULD forbid "porting and polishing" or otherwise try to mandate a bone stock airflow passage.

When setting this straight, particular attention needs to be paid to the L2 9.1.5.E.2 subsections b through m (ie areas within the power train but not within the drive train) to make sure that no loopholes are opened.

I believe that the above approach puts the rules back to where they were meant to be and where most competitors thought they still were.

I'd be happy to speak or correspond further with any PAC members reading this, and would be happy to help fix the rule language.


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 Post subject: Re: Level 2 carburators?
PostPosted: Thu Aug 13, 2020 8:18 am 
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Letter written asking for this to be fixed. It is #29406 is anyone wants to add on.

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 Post subject: Re: Level 2 carburators?
PostPosted: Thu Aug 13, 2020 8:59 am 
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May I ask: How did you describe the problem and what did you ask for?


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 Post subject: Re: Level 2 carburators?
PostPosted: Thu Aug 13, 2020 4:57 pm 
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I didn't get into the powertrain/drivetrain issue as you outlined. That does not involve the induction system IMHO. I just pointed out that the changes that were made last year rendered the level 1 carbs with no ability to modify them per the rules even though fuel injection throttle bodies and butterfly valves can be ported and polished and otherwise modified. I also asked that the wording calling for level 2 induction systems to remain stock be reinstated.

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 Post subject: Re: Level 2 carburators?
PostPosted: Thu Aug 13, 2020 6:33 pm 
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Understood.

IMO - though I obviously can't prove it - the L1/L2 carburetor prep rules screwup was a byproduct of mistaken attempts to work around the typo / drafting error (drivetrain vs powertrain) that I'm trying without apparent success to point out.

I think that carb/TB prep is the most significant but not the only mistake stemming from this.

Al


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