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Body heights?


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#1 Tampabay racer

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Posted 28 February 2013 - 01:05 PM

Can someone tell me the body heights are for all three classes? I can seem to never pass tech on our monthly races...

Brian Ambrose





#2 John Streisguth

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Posted 28 February 2013 - 01:35 PM

1.375" for Can-Am, GTC, and F1 with the rear wings. 1.125" for non-winged F1s.
 
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#3 Fast Freddie

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Posted 28 February 2013 - 01:56 PM

The problem with body height measurement is that it's taken on a flat tech block with the car setting on all four tires or the guide and rear tires.

The problem with that is the diameter of the rear tires affect that measurement. The height of the body with a .8125" tire will be shorter than the height using a .8225" tire. When you see a maximum body height measurement of 1-3/8" or 1-5/8 in reality it's not refering to the body at all but the distance from the block surface to the top edge of the body. It's always a good rule of thumb to cut your body 1/16" less than the legal height. This should be just about right if your running .062" clearence and just a tad short if your running .050 clearence.

The ISRA North American rules are the only set of rules I know of were the body height is measured on a tech block with wheel cutouts. That way you get a true body height measurement unaffected by different tire diameters. So when you cut your bare body to exactly 1-5/8 you can be sure it will pass tech.

That way you can also run the same body, let's say a GTP body, on the flat track with a .032" clearence or on a high banked track with .062" clearence just by swapping chassis and tires, or in some cases just tires.
Fred Younkin

#4 Mopar Rob

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Posted 28 February 2013 - 02:37 PM

Brian,

So in a nutshell cut you Can-Am body in the rear at 1.300" to compensate for the .050" clearance plus a little wiggle room in case your tires are big.

Rob Hanson

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#5 Noose

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Posted 28 February 2013 - 03:10 PM

That's right, it is the height of the body on the test block and that's how it was intended to be written and not for manufacturing. It is not a big problem in tech these days.

Joe "Noose" Neumeister
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#6 The Number of

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Posted 28 February 2013 - 03:39 PM

That's right it is the height of the body on the test block and that's how it was intended to be written and not for manufacturing.  It is not a big problem in tech these days.

 
  And this R4 will go into history as the year of the great body height bounce. :D 
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#7 The Groove

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Posted 28 February 2013 - 08:42 PM

Brian,

Go to the Precision Slot Cars WEBSITE select category "Retro", and go to page 2, Retro tech tools.

psca.jpg

They are so easy to use and make checking body height a breeze!
Rich Attee, THE GROOVE-PSC race team

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#8 Noose

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Posted 01 March 2013 - 08:49 AM

Rich,

Great advice as those are the tools I use!

Joe "Noose" Neumeister
Sometimes known as a serial despoiler of the clear purity of virgin Lexan bodies. Lexan is my canvas!
Noose Custom Painting - Since 1967
Chairman - IRRA® Body Committee - Roving IRRA® Tech Dude - "EVIL BUCKS Painter"
"Team Evil Bucks" Racer - 2016 Caribbean Retro Overall Champion
The only thing bad about Retro is admitting that you remember doing it originally.






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