Street Prepared Class - Wheel Calc. Question
Posted: Tue Apr 30, 2013 9:15 pm
I'm doing the calculations to determine the SP class of my car.
The question I have involves calculated adjustments for wheel size and width of my current wheel setup vs factory available option size for my year/model;
(e.g., the 2003 Subaru WRX had a factory BBS wheel option of 17"x 7").
The wheels I"m currently running are 18" x 8".
Would this calc. adjustment net out to:
a) A "zero" adjustment, based on a -2% for 1" LARGER rim dia. and +2% for using a 1" wider rim, or
b) 4% total adjustment based on deviation, regardless of whether it's up or down, from factory option sizing. I would think that INCREASING the wheel diameter would result in a negative performance advantage (size/weight).
Please let me know your thoughts.
Thanks!
The question I have involves calculated adjustments for wheel size and width of my current wheel setup vs factory available option size for my year/model;
(e.g., the 2003 Subaru WRX had a factory BBS wheel option of 17"x 7").
The wheels I"m currently running are 18" x 8".
Would this calc. adjustment net out to:
a) A "zero" adjustment, based on a -2% for 1" LARGER rim dia. and +2% for using a 1" wider rim, or
b) 4% total adjustment based on deviation, regardless of whether it's up or down, from factory option sizing. I would think that INCREASING the wheel diameter would result in a negative performance advantage (size/weight).
Please let me know your thoughts.
Thanks!