gear sets? What is stock?

It says Stock ratios very clearly. It also says a Stock transmission. Once gears are changed in a Stock transmission, it is no longer Stock.

That means mixing and matching between gearboxes is not allowed. If the CRX HF has a better box than the SI, then you can run the entire HF box, but not certain gears.

Obviously, Lawrence didn't think the intent was to be able to mix and match or he would have run at the base weight. He probably knew it was a gray area and didn't want to risk the championship.

Needs to be clarified if there are this many questions.

I agree that this is horrible to police. Not sure that was given enough thought when the penalties and options were written.
 
Maybe the rule should say, "If you intend on being torn down at the Runoffs, run at least the 2.5% penalty weight."
 
Very interesting topic which I have been following very closely. With Daytona coming up, maybe there are additional or other areas that need to be checked for compliance. Keep up the good work! I built my own Webster boxes for our sprites/midgets so I know the benefit of mixing gear sets. One I always liked was the gears for final drive that were not 1 to 1. Made a 4.2 or 4.5 rear end something in between on the H & G car.
 
Tom Feller":141zuguv said:
It says Stock ratios very clearly. It also says a Stock transmission. Once gears are changed in a Stock transmission, it is no longer Stock.

That means mixing and matching between gearboxes is not allowed. If the CRX HF has a better box than the SI, then you can run the entire HF box, but not certain gears.
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I disagree. The engine classified should dictate what is a stock box. A gearbox change from the HF into SI wouldn't be stock- add 2.5% Mix and match- add 2.5%
 
I don't. Primarily because of this particular line in the PCS:
Classification will be based on the specifications of the base model of the car, as it was delivered for sale in the United State
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If that's the case, and as far as I'm concerned it is, then ANY gearbox that was available in any of the models (base or otherwise) the US market for that particular model should be able to be used with no penalty. It's still a stock gearbox whether it came in the HF, DX, or Si, if everything is based on the 'base model' at any rate. With this line of thinking then if someone were to use a gearbox from an Si when the Si wasn't listed in the spec line (which it is not in the 88 & later models) then you guys would say they should impose the +2.5% weight penalty.

Guess what? There is no difference in the gear ratios other than final drives. Not positive, but I'm pretty sure the same can be said for the HF gearbox too.

W
 
Many of the cars in Production are also listed in the Improved Touring Rules. The IT Spec Line for each of those cars lists the stock transmission ratios. Those cars should have these ratios also listed on the Production Spec Line. That should be an easy copying of information.
A fine procedure for checking the transmission ratios without any tear down other than removal of spark plugs was written by Richard Crowell, a National Tech/Engineer/Rocket Scientist (at Huntsville). Our transmission ratios have been checked by that procedure (doesn't require a rocket scientist) at the American Road Race of Champions at least twice. Any Divisional Tech should be able to perform this check with the written procedure in hand.
I also suggest the transmission ratio check procedure should be included on SCCA.com in "Cars and Rules" under "Scrutineering Forms and Procedures". Using this form, any racer should be able to check his own car to assure the ratios are legal. And this check should be done at times at Majors at least.
 
Jay Griffin":b3shomty said:
With this line of thinking then if someone were to use a gearbox from an Si when the Si wasn't listed in the spec line (which it is not in the 88 & later models) then you guys would say they should impose the +2.5% weight penalty.
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Stock – In the exact same state or location as supplied by the original manufacturer.
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Since the Si gearbox was not supplied on the base model, it is not legal to use, without the 2.5% penalty.

That means, you can't put any gearbox in the car, except the stock one. The stock, unmodified, as delivered on the base model, transmission. Stock. As supplied.

Just because it's from the same manufacturer, doesn't make it the stock transmission AS SUPPLIED on the base model.
 
blamkin86":1xo4m8bf said:
Jay Griffin":1xo4m8bf said:
With this line of thinking then if someone were to use a gearbox from an Si when the Si wasn't listed in the spec line (which it is not in the 88 & later models) then you guys would say they should impose the +2.5% weight penalty.
Click to expand...
Stock – In the exact same state or location as supplied by the original manufacturer.
Click to expand...

Since the Si gearbox was not supplied on the base model, it is not legal to use, without the 2.5% penalty.

That means, you can't put any gearbox in the car, except the stock one. The stock, unmodified, as delivered on the base model, transmission. Stock. As supplied.

Just because it's from the same manufacturer, doesn't make it the stock transmission AS SUPPLIED on the base model.
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I believe that they use the base model wording to make sure that things like spoilers and such aren't used on a car that didn't come with them. I would agree with your interpretation with the additional words that would include any car on the same spec line of the GCR. You do have the right to update/backdate but not use parts from other cars which are not on the spec line, even if they happen to fit.

Clearly this needs some clarification before someone loses a championship over it. I see that a letter has been sent so this issue should be taken up.

On another point, Kyle was asking about straight cut gears. Those ARE allowed with the 2 1/2 percent penalty. They are a better racing gear because of lower friction due to less teeth in mesh. They are also noisier for that reason which is why they aren't used on street cars.
 
Ron's point about the straight cut gears is exactly the reason I would NOT use Rich's "roll it in gear" method for Runoffs compliance. No need to check just a part of the rule. And Rich's method is time consuming. With multi cars in impound, it would mean all stay longer. The goal set for tech is all cars completed in 4 hours or less.
 
billp":yy18y9n8 said:
Many of the cars in Production are also listed in the Improved Touring Rules. The IT Spec Line for each of those cars lists the stock transmission ratios. Those cars should have these ratios also listed on the Production Spec Line. That should be an easy copying of information.
A fine procedure for checking the transmission ratios without any tear down other than removal of spark plugs was written by Richard Crowell, a National Tech/Engineer/Rocket Scientist (at Huntsville). Our transmission ratios have been checked by that procedure (doesn't require a rocket scientist) at the American Road Race of Champions at least twice. Any Divisional Tech should be able to perform this check with the written procedure in hand.
I also suggest the transmission ratio check procedure should be included on SCCA.com in "Cars and Rules" under "Scrutineering Forms and Procedures". Using this form, any racer should be able to check his own car to assure the ratios are legal. And this check should be done at times at Majors at least.
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No reason to add pages to the GCR. We require that you provide a copy of your factory shop manual if needed in impound, the stock ratios for your car should be listed in there. The rest is just math.

I suspect you will see a clarification in an upcoming Fastrack.
 
Good point.

What if I were to make all straight cut gears, but all stock ratios. How would that procedure catch that?

I have never, ever seen anyone check gear ratios in the tech shed. I haven't been around since the 60's, but I think Ive been in the tech shed enough to make a valid point.

And if this method is counting the amount the tire rotates vs the engine, well there's waaaay to much error in that process. An estimation at best.

And yes, I ran the 2.5% because I didn't want to risk the championship, but more importantly, the possibility being labeled a cheater and discrediting all of our wins etc.
 
SPEEDSHAK":3vqmfgzz said:
Good point.

I have never, ever seen anyone check gear ratios in the tech shed. I haven't been around since the 60's, but I think Ive been in the tech shed enough to make a valid point.
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Dude, your in the wrong class. :mrgreen:
 
Regarding the IT/STL posts - Really a bad decision by the STAC in my opinion. As was stated it penalizes the cars that have cluster gears on the countershaft, IE LBC's. Maybe others? I believe that they had the wording right in the first place.

As for straight cut gears, if someone was crazy enough to have special straight cut gears made with the OEM ratios, who cares? They spent a lot of money to save some frictional losses. No one would do that. If you are making special gears you change the ratios and add your 2.5 % weight penalty.

If it is impossible to inspect and police, one way out of this is to add 2.5 % to all LP cars and do away with the weight advantage of a bone stock transmission. That penalizes anyone who can't come up with a close ratio alternative with synchros. Probably not a good solution.
 
I would not say that straight cut gears are things to dismiss. Enough of small things are what can make the difference in a race. It was enough small thing that almost killed Production racing.
 
Mike Cummings":2hd7q4j6 said:
I would not say that straight cut gears are things to dismiss. Enough of small things are what can make the difference in a race. It was enough small thing that almost killed Production racing.
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Are you talking about straight cut gears with stock ratios? C'mon Mike, no one would do that. You could buy a dog box tranny for the cost of making those gears with no real advantage in gear ratio. And for what? To save frictional losses and lower thrust loads? Helical gears are actually stronger due to higher contact ratio because there are more teeth in mesh.
 
Ron Bartell":1mmdi4x4 said:
Are you talking about straight cut gears with stock ratios? C'mon Mike, no one would do that. You could buy a dog box tranny for the cost of making those gears with no real advantage in gear ratio. And for what? To save frictional losses and lower thrust loads? Helical gears are actually stronger due to higher contact ratio because there are more teeth in mesh.
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People have been known to put $10,000 into a "stock" 1.8L Mazda engine for a spec class too.. ;)
I'm not saying it makes sense to spend $4k on a straight cut stock ratio gearset, I'm only saying people have spent more for less..
 
Matt - I know well that people spend 10 to 12 grand for a "stock" motor. That actually gets you something. No one is going to spend big money for a gearbox that saves your frictional losses. I said you could buy a dog box for the cost of the gears. With the splined layshaft and all it is probably on the order of TWO dogboxes. Try pricing one-off hardened gears with an internal spline and an integral synchro cone. Let's not get carried away with hypotheticals.
 
Ron, I don't disagree with you at all. All comments were tongue in cheek and pointed mainly at the SM plunge cut debacle where an engine builder tells the tech shed 'this doesn't do squat' and then immediately thereafter tells the customer 'All the fast guys are doing it- you gotta do it or you'll be left behind. That'll be an extra $1500 please'. I smell something here and it ain't roses!

Remember we're already into silly season and people do silly things when they think about gaining 5hp and still keeping that 50lbs off the car for using "Stock" gears. All theory and conjecture and things to laugh about while drinking a beer and working on the car..
 
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