WHEEL SIZES AND OFFSETS
Note - For widths not list here, following the centerline-to-mounting face or mounting face-to-outside edge dimension is preferable to using the backspacing specification. Unfortunately, most wheels are sold by the backspacing dimension, so the other dimensions must be calculated. (Tire Size Calculator)
For machining reference, basic drawings of the front and rear Pin-drive hubs are here.
| PDF
drawings of Pin-drive wheels (Backspace similar to bolt-ons of the same width | |
| Bolt-on hub dimensions |
All dimensions are +/- 0.15" |
Bolt-on Wheels | |
15" Torque-Thrust:
Note that the optional 4-piston Sierra/Wilwood/Coleman
brakes will not fit
in these wheels! |
 |
A Dimensional Comparison of 15" FIA and 427 Pin Drive Wheels | |
| Both the FIA (left) and 427 (right) are shown. Note that the wheels on both cars come very close to the bodywork. The 1/2" difference between the wheel offsest will very likely make the wheel rub. At the very least, it will look "wrong". |
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| The same problems occur in the rear. | |
17" Wheels: The backspacing is the same for bolt-on and pin-drive designs except as noted. | |
| The distance from mounting face and inner face is critical for 4-piston caliper clearance. These wheels may be used with 275/40 and 315/35 tires. Note! Bolt-on Wheels Only: Add 0.3" to the backspacing when used with the ERA rear suspension. | |
| Safety wiring of the pin-drive-wheel wing nut shown here. | |
Rear variationsIt's important to note that the under-car exhaust cannot be used with wheels with more than 3.88" backspacing. |
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