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Prepared Class Questions.

Posted: Wed Dec 30, 2015 4:34 pm
by Super1303
I can't seem to figure this out, I need a little help.
I'm building a new engine and want to know how it factors in.

First: C. Cars with a throttle plate area of less than 0.65 mm2/cc : Deduct 12% of
actual displacement. :?:
-I have, currently, an 1835cc engine with Two 40mm throttle plates. I can't seem to make this math work.
With the strokes available I can build a 2210cc engine using the same carbs. But with this factor, if it applies, dose it give me that -12% making it a 1945cc engine keeping me in P3?

Also what or where is: Sec. 2.C.4 (DOT tires)
-Not that I'm going to base my engine on this but I'd like to know.


PREPARED 1 – Cars with a displacement of 4501cc to 8000cc.
PREPARED 2 – Cars with a displacement of 2201cc to 4500cc.
PREPARED 3 – Cars with a displacement of 1601cc to 2200cc.
PREPARED 4 – Cars with a displacement of 1600cc and less.

Thanks, Evan

Re: Prepared Class Displacement Factor Questions.

Posted: Wed Dec 30, 2015 6:03 pm
by 3rdgendennis
2....
C. Wheels/Tires
3. Street tires: visible tread the full width of the tire, no cord separation,
DOT#, good tire condition.

looks like 4 is missing or was revised at some point.

40mm^2*pi/4=1256.637 mm2
1256.637*2=2513.274 mm2
2513.274mm2/2210cc=1.137mm2/cc

Re: Prepared Class Displacement Factor Questions.

Posted: Wed Dec 30, 2015 6:56 pm
by Super1303
Awesome!
The 4 is where I was lost, were's the 4?? Is this 4 somewhere I don't know about?
OK thanks, got it.

So my math wasn't toooo far off, makes me feel better. :D
Now I see how it's applied.

Thanks again.

Re: Prepared Class Displacement Factor Questions.

Posted: Sun Jan 03, 2016 11:09 pm
by walterclark
You probably figured it out, but just in case...The description of the requirements for tires to get the P class 12% credit is in the Tech and Safety Requirements, not Classification.

Re: Prepared Class Displacement Factor Questions.

Posted: Tue Jan 05, 2016 7:33 pm
by KevinGale
We must have revised it. We sometimes have to renumber when something is dropped and sometimes we miss a reference. I'll try to remember to clean this up when I edit in the changes this year.