December 2013 Fastrack

[Greg Amy]

STL now has weight penalties (understandably) for certain engines, RWD/AWD, etc... are these applied successively, or are they summed before applying the cumulative % penalty over the chart?

I believe any adjustments are each done as a percentage of base weight, then all added to the base weight.

I would disagree, Eric. STx is an engine-centric category, and the engine weight is the baseline for everything. Additions for specific engines should be factored into that baseline. So IMO you'd tally up all the stuff for the engine, and that's now your new base weight for the chassis it's installed into.

Example: B18C5 Type R engine installed into an S2000 chassis. Engine is 1.8L so 2430 pounds. B18C5 get +2%, so 2479. Gets installed into a RWD S2000 chassis, so +5.5% over 2479, thus 2615#.

If there's reasonable disagreement in this, then it's something we should clarify/codify.

- GA

[Chip42]

don't wait for disagreement, codify it NOW before there's a problem. again, that problem is AT WORST 3 lbs with a 2% engine modifier but if this system becomes a more common practice, you could expect that delta to grow.

and as I said above, 3 lbs is enough to bump you at impound, and it's 3# higher the tGA way than the tEH way. just state the order of operations, and do that every time you add percent weight changes to other allowances.