ORIGINAL: pauljmcnulty
Happy to learn here, but what on earth would be the difference in the shell? I understand that other parts might be better, suspension etc., but does the mileage on a car's shell actually make it worth the cost of an engine transplant? [8|]
Shells do eventually wear out. Leaving aside corrosion, every bump in the road is ultimately transmitted to the shell, cushioned via the suspension. This causes flex and fatigue, and ultimately things lose rigidity or start to crack in areas where the loads concentrate. If a given car is...
- softly sprung
- driven gently
- on super-smooth German motorways
- with no history of accident damage
.. it is likely to cope with starship mileage before it starts to lose rigidity or develop cracks.
But change any of those factors for less favourable ones and every factor you change reduces the useful life of the shell. So, if an apparently identical sister car has any of the following factors...
- on stiff spring and damper rates and ARBs
- driven hard, harder acceleration, braking and cornering
- on rough roads, or on tracks involving enthusiastic attacks on the kerbs
- history of accident damage
... then any of those factors will use up the shell life a bit, and reduce the available mileage before it shows signs of significant wear. If several of those factors are applicable, they multiply each other. You can wear out the shell on a car used for forest rallying in just a few thousand miles, andon something like the Escort rally cars I used to be involved with the full roll cage and other bodyshell reinforcements are as much to lengthen the useful life of the shell as to protect the occupants.