ABSTRACT
An attempt was made to compare the aerodynamic forces acting on Subaru WRX
STi version IV (SPC) with a recommended World Rally Championship (WRC) and a
non-recommended GT Wing Type-A (GTA) spoilers. The experiment was done with
the following combination, SPC, SPC+WRC (REC), and SPC+GTA (NRE). The
above experiments were carried out at a Reynolds Number (R) range of 2.19 x 104 to
10.94 x104 and an angle of attack (
) of 0° to 20°. The lift coefficient (CL), drag
coefficient (CD) and side force coefficient (CS) are computed from the measured data
From the analyzed data, it was found that, for REC. CL decreased in the almost all
the investigated ranges of
and R. The maximum decrease in CL is about 40% (at

= 20°). On the other hand for NRE, CL increases for almost all the investigated
ranges of
and R. The maximum increase of CL is about 177%. At, 2.19 x
104R6.57 x 104, there is little or no changes in the value of CD for REC and SPC in
the investigated ranges of
. It was found that value of CS for REC is less than that of
NRE in the investigated ranges of
and R.