For SSM, there is no allowance for replacing or adding a diffuser. That means you can't touch oe... not even to fill the hole.
I'm not versed on the XP rule set.
I'm not versed on the XP rule set.
Where are you getting that diffuser rule? SSM rules do not allow diffuser change from OE.My reading shows a 25" diffuser with strakes a minimum of 6" apart is allowed, my diffuser meets these rules (difflow railer I think), can anyone show me I am wrong?
It does look like the GRP wing above would NOT be AX legal in any class?
SCCA SM rules said:K. Aerodynamic Aids: Wings may be added, removed, or modified. Non-OE
wings may only be attached to the rear deck/hatch area behind the center-
line of the rear axle. The total combined surface area of all wings shall not
exceed 8 sq. ft. (0.7432 m2) as calculated per the Wing Area Computation
in Section 12. The number of wing elements is limited to 2.
Wings, and any component thereof, may not extend beyond the vehicle
width, as defined by the outermost portion of the vehicle doors, less mir-
rors, door handles, rub strips, and trim. In addition, no portion of the wing
or its components may be more than 6.0” forward of the rear axle, more
than 0.0” beyond the rear most portion of the bodywork, or more than 6.0”
above the roofline of the vehicle, regardless of body style. For convertibles
and roadsters, the highest portion of the windshield frame will be consid
ered the highest portion of the roof; however, a convertible or roadster uti
lizing a hardtop will use the highest portion of the hardtop as the roofline.
Reinforcements to the wing mounting area may be used, but may serve no
other purpose. Body panels to which a wing mounts must remain func
tional (e.g., trunk lids and rear hatches must open). Wing endplate surface
area is limited to 200 sq. in. (1290.3 cm2) each and limited to a maximum
Except for standard parts, wings designed to be adjustable while the car is
in motion must be locked in a single position.
Canards are allowed and may extend a maximum of 6.0” (152.4 mm) for
ward of front bodywork as viewed from above. No portion of the canard
may extend past the widest part of the front bodywork/fascia as viewed
from above. Canard area will be measured in the same manner as wings
using Section 12. Canard area may not exceed 15% of total wing
allowance. The sum of canard area and rear wing area may not exceed the total
L. Front splitters are allowed and shall be installed parallel to the ground
(within ±3° fore to aft) and may extend a maximum of 6.0” (152.4 mm)
from the front bodywork as viewed from above. Splitters may not extend
rearward past the centerline of the front wheels. No portion of the splitter
may extend beyond the widest part of the front
bodywork as viewed from above.
Aerodynamically functional vertical members, such as splitter fences
or endplates, are not allowed.
You can run one in Modified (DM or EM)... Don't know about XP, but I dont see any allowance in the Prepared rules. XP is weird though. Find a rear photo of the BWR XP car.What class can I run in with a diffuser? It looks like it is even banned in XP? Sorry I just searched for diffuser and thought I was in a different section then I was.
I did, that was my research into XP Easier then reading the rule book. Now back to the book to figure which of those is appropriate...You can run one in Modified (DM or EM)... Don't know about XP, but I dont see any allowance in the Prepared rules. XP is weird though. Find a rear photo of the BWR XP car.