Whitey
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Hey all,
There has been a lot of discussion over the last 10 years about custom valved Bilstein struts and shocks sold by Auto-craft in Melbourne. Many Pradopoint members have purchased these struts and shocks so I thought it would be interesting to compare the difference in valving between the standard BE5-A712 and the Auto-craft custom valved 712.
I have recently documented a Bilstein database for Prados and FJ Cruisers, showing both strut and shock lengths and valving, see here;
http://www.pradopoint.com/showthread...hs-and-Valving
The standard Bilstein strut for the Prado is the BE5-A712 strut. The custom valved 712 struts sold by Auto-craft also carry the part number BE5-A712.
With access to independent dynamometer facilities and suspension engineers, we are now in a better position to understand the difference in valving for Auto-craft 712 struts. The plot below compares dynamometer data for a custom valved 712 from Auto-craft with a standard BE5-A712;
The solid line represents the Auto-craft 712, the dashed line the standard BE5-A712.
It is immediately apparent that the valving curves closely follow each other, with the suspension engineer indicating that there has been no change in the shim stack or the shaft/piston diameter of the Auto-craft 712. If the stack or shaft/piston had been modified, the shape of the valving curve would look very different. The variation you can see between the solid and dashed lines is well within typical valving tolerance of ca. +/- 300N at high velocity. If you tested a few standard BE5-A712 struts, you’d see a similar variation. The specified valving at 0.52m/s for a standard BE5-A712 is 2365N:2135N. As you can see, the Auto-craft 712 strut is actually closer to spec values than the standard BE5-A712 that was tested.
To further investigate, an Auto-craft 712 was disassembled. After removing the striker plate, it could be observed that the circlip had not previously been removed, and the paint has not been disturbed. As such, the strut has not been modified in any way since its construction in Germany.
So the answer to the question is simple, NO, Auto-craft 712 struts are NOT custom valved. Auto-craft 712’s are in fact standard BE5-A712’s.
Best
Mark
There has been a lot of discussion over the last 10 years about custom valved Bilstein struts and shocks sold by Auto-craft in Melbourne. Many Pradopoint members have purchased these struts and shocks so I thought it would be interesting to compare the difference in valving between the standard BE5-A712 and the Auto-craft custom valved 712.
I have recently documented a Bilstein database for Prados and FJ Cruisers, showing both strut and shock lengths and valving, see here;
http://www.pradopoint.com/showthread...hs-and-Valving
The standard Bilstein strut for the Prado is the BE5-A712 strut. The custom valved 712 struts sold by Auto-craft also carry the part number BE5-A712.
With access to independent dynamometer facilities and suspension engineers, we are now in a better position to understand the difference in valving for Auto-craft 712 struts. The plot below compares dynamometer data for a custom valved 712 from Auto-craft with a standard BE5-A712;
The solid line represents the Auto-craft 712, the dashed line the standard BE5-A712.
It is immediately apparent that the valving curves closely follow each other, with the suspension engineer indicating that there has been no change in the shim stack or the shaft/piston diameter of the Auto-craft 712. If the stack or shaft/piston had been modified, the shape of the valving curve would look very different. The variation you can see between the solid and dashed lines is well within typical valving tolerance of ca. +/- 300N at high velocity. If you tested a few standard BE5-A712 struts, you’d see a similar variation. The specified valving at 0.52m/s for a standard BE5-A712 is 2365N:2135N. As you can see, the Auto-craft 712 strut is actually closer to spec values than the standard BE5-A712 that was tested.
To further investigate, an Auto-craft 712 was disassembled. After removing the striker plate, it could be observed that the circlip had not previously been removed, and the paint has not been disturbed. As such, the strut has not been modified in any way since its construction in Germany.
So the answer to the question is simple, NO, Auto-craft 712 struts are NOT custom valved. Auto-craft 712’s are in fact standard BE5-A712’s.
Best
Mark
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