Check your nuts.
06-21-2007, 11:06 PM
#3
Race Director
Member Since: Oct 2000
Location: Deal's Gap 2004 NCM Motorsports track supporter
Posts: 13,915
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Tom, I have a seat question; is a back brace required for my driver side Sparco Evo for VIR? I have the b/k harness bar with simpson harnesses on both seats with factory passenger seat (modified for belt pass through).
06-22-2007, 04:54 PM
#6
Le Mans Master
There is some commentary on that incident in an earlier thread (06-12-2007).
[vid] what happens when you borrow the wrong wheels
On the same theme, here is a caution for owners of cars that
use bolts for wheel attachment.
If you purchase aftermarket wheels and buy the optional wheel
mounting kit, be sure to examine the bolts that are supplied
to ensure they provide adequate thread engagement.
Not only were the tapered shoulder on bolts for a BMW considerably
smaller in diameter and taper length than OEM. The aftermarket
threaded shank was 19% shorter than OEM.
A rule of thumb is that thread engagement in cast iron should be at
least equal to 1.0 to 1.5 times the major diameter of the bolt shank
(in steel, 0.75 to 1.0 times diameter).
I don't know whether the BMW hub is cast iron or steel. The OEM
M12 bolt offers 10.7 mm - ok for steel, short for iron. The aftermarket
bolt only offers 8.7 mm - too short for steel, and much too short for
iron.
.
[vid] what happens when you borrow the wrong wheels
On the same theme, here is a caution for owners of cars that
use bolts for wheel attachment.
If you purchase aftermarket wheels and buy the optional wheel
mounting kit, be sure to examine the bolts that are supplied
to ensure they provide adequate thread engagement.
Not only were the tapered shoulder on bolts for a BMW considerably
smaller in diameter and taper length than OEM. The aftermarket
threaded shank was 19% shorter than OEM.
A rule of thumb is that thread engagement in cast iron should be at
least equal to 1.0 to 1.5 times the major diameter of the bolt shank
(in steel, 0.75 to 1.0 times diameter).
I don't know whether the BMW hub is cast iron or steel. The OEM
M12 bolt offers 10.7 mm - ok for steel, short for iron. The aftermarket
bolt only offers 8.7 mm - too short for steel, and much too short for
iron.
.