Bear with me on this question; I'm coming from the Miata autocross crowd where the trade is all about handling tech.
The OEM front shock tower brace and nearly all of the aftermarket FSTB's mount to the shock towers using the two inner bolts. Only one aftermarket FSTB that I can find utilizes four bolts per side, or all eight available bolts.
On the Miata, heavy torque loads between the shock towers -- which the brace is designed to mitigate -- can flex the tower mounts themselves slightly, momentarily twisting suspension geometry. We've found that the problem is much worse with FSTB's using only the two inboard bolts on the tower, which is why every aftermarket FSTB uses all three bolts on the Miata (six bolts total) -- in addition to a secondary piece angling back and bolting to the firewall.
It seems to me that a heavier car like the Mustang (+1400 lbs.) with more power (+260 hp) would place even more torque loads on the shock towers, and would require a full 4 bolt per side mount to distribute the load and avoid tower flex and momentary twists in suspension geometry -- to say nothing of long term mount fatigue over the life of the vehicle. In terms of materials composition, sheet thickness and reinforced stress points, and design, I can find little difference between the tower mounts and strut/shock plates of both vehicle, relative to their different weights and power.
Is it that most FSTB's for the later model Mustangs, including the OEM, are poorly designed, or am I missing something?
The OEM front shock tower brace and nearly all of the aftermarket FSTB's mount to the shock towers using the two inner bolts. Only one aftermarket FSTB that I can find utilizes four bolts per side, or all eight available bolts.
On the Miata, heavy torque loads between the shock towers -- which the brace is designed to mitigate -- can flex the tower mounts themselves slightly, momentarily twisting suspension geometry. We've found that the problem is much worse with FSTB's using only the two inboard bolts on the tower, which is why every aftermarket FSTB uses all three bolts on the Miata (six bolts total) -- in addition to a secondary piece angling back and bolting to the firewall.
It seems to me that a heavier car like the Mustang (+1400 lbs.) with more power (+260 hp) would place even more torque loads on the shock towers, and would require a full 4 bolt per side mount to distribute the load and avoid tower flex and momentary twists in suspension geometry -- to say nothing of long term mount fatigue over the life of the vehicle. In terms of materials composition, sheet thickness and reinforced stress points, and design, I can find little difference between the tower mounts and strut/shock plates of both vehicle, relative to their different weights and power.
Is it that most FSTB's for the later model Mustangs, including the OEM, are poorly designed, or am I missing something?
