On Compression

[LEAD LAP]

On the topic of compression numbers, does anyone know what the variance is at Riverhead when checking compression on the Truck motors, either before or after a race ?

I see in the rules it says 9.0 max, but there's no mention of a plus/minus.

Thanks.

[fisherman]

I'll get deleted for this answer, but just my thought: DEPENDS ON WHO YOU ARE, AND NOT WHO YOU ARE!

[LEAD LAP]

Seriously Now. Wouldn't the EXACT numbers change from one day to the next, from one race to another, from beginning of the season to the end ? There has to be some leeway spelled out, whether its a tenth of one compression point, or half a tenth, whatever. (I'm sure the compression rate falls as wear is put on the engine).

[art11758]

There should be leeway simply for the method of enforcement chosen. The static compression ratio is determined mathematically by volume measurments.
To enforce it any other way, while it may be expedient, is subject to parasitic losses and other variance. Of course there will be other opinions, this is just mine.

[Tower Man]

Basically it's like this, if the rule is 9.0 and you come up 9.1, you are illegal. For a while there it was off .2, so a 9.0 to 1 could have been a 9.2, but they have since had it recalibrated.