Quote Originally Posted by Benson View Post
So why do people run forged rods in their turbo motors with >15psi through the motor and cap the revs to 7200rpm? i.e EVO's

IF what your saying is right string, then people dont need forged rods
I haven't discussed the strength of the rods in compression because I'm not qualified to make comments - I don't know anything about the specific materials in question. You can't avoid a higher torque combustion event from pushing down on the crankshaft (through the connecting rod) harder - if you're making more power than a stock cast rod can handle in compression (or handle in the event of detonation) then you'll have to go for a stronger item.

Quote Originally Posted by aaronng View Post
As long as your are generating more combustion force than stock, that means the other piston in the intake cycle would experience a stronger elongation force when it is being pulled down by the crankshaft.
Consider two engines, one 10% more torquey than the other but otherwise identical. They are both connected to a load which holds the engine speed constant (one load is 10% larger obviously). One engine is putting out 10% more power but both are operating at the exact same speed.

In both cases, the rods and pistons are moving at identical rates. If two objects have equal positions at all points in time, they also have equal velocities and equal accelerations. Since they have equal accelerations, we know that from F=ma, they must both be receiving the exact same force, even though one engine is producing 10% more power than the other.