Main

TECH ADVISORY
SFI Specification 2.3K
Rear Engine Dragster Roll Cage; 6.29 Seconds E.T. and Quicker
Effective: August 24, 2004

The below paragraphs regarding Wing Strut Attachment Requirements have been revised as follows, effective immediately. New wording is shown in bold text. This tech advisory is meant to supplement SFI Spec 2.3K and does not replace or supercede any other requirements within that spec version.

Page 16, Modify Paragraph IV.5.A.3.B)

From 0^o to 90^o centerline of axle to centerline of mounting hole upward to be no greater than a ~~7.5 inch (19 cm)~~ 8.5 inch (21.6 cm) radius.

Page17, Add New Paragraph IV.5.A.3.G)

A Connector Bar must connect the bottom main strut attachment bolts at the rear end plate attachment point, connecting the 1/2" fasteners from side to side, in between the main strut tabs. The Connector Bar shall be 1 1/8" x .058" 4130 chrome moly steel tubing. In lieu of this Connector Bar, the wing rear end attachment plates may be made of 3/8" (9.5 mm) 4130 chrome moly steel.

Page 18, Modify First Paragraph of Section IV.5.C. GENERAL

Minimum thickness of attachment tab to chassis and sta rod to main support shall be 1/8" (3.2 mm) SAE 4130N. Minimum thickness of attachment tabs to the main strut and sta rod shall be two (2) tabs of 1/8" (3.2 mm) AND one tab of 3/16" (4.8 mm) OR two (2) tabs of 1/8" (3.2 mm) WITH a 3/4" diameter bushing, .250" thick welded in full circumference on the outside plane of both 1/8" (3.2 mm) tabs. Bolts, main strut to ~~chassis~~ rear end plate shall be ~~7/16" (11.1 mm)~~ 1/2" (12.7mm) for Top Fuel and 3/8" (9.5 mm) for Alcohol. Bolts, main strut to wing shall be 3/8" (9.5 mm), sta rod to main strut and sta rod to chassis shall be ~~3/8" (9.5 mm) for both Top Fuel and Alcohol~~ 7/16" (11.1 mm) for Top Fuel and 3/8" (9.5 mm) for Alcohol. The distance from the center of any bolt hole in the wing support tabs and/or brackets to the edge of the tab/bracket must be at least 1 1/2 times the bolt diameter. Wing stand attachment points must be in double shear. All attaching bolts shall be SAE Grade 5 or better and no PIP pins permitted.