i tried a car with newton vehicle joint(not the custom multipartcar thingy.),

with both newton 1.53(ventilators wrapper) and newton 2 open beta(with Vet's wrapper), both working but has a problem(both has same problem):

tried with diffrent mass/size/hulltypes, but when i release car from a hill like this:


car goes down with CONSTANT speed, where it should get faster(because it goes down from a hill laugh )

i can only suspect this line, but i am not sure how to solve it:
Code:
void onforceandtorque(NewtonBody* body)
{
	float mass, ixx, iyy, izz;
	NewtonBodyGetMassMatrix(body, &mass, &ixx, &iyy, &izz);
	NewtonBodySetForce(body, vectorf(0, 0, -9.8 * mass));
}


this is the forceandtorquecallback of the car body.

any suggestions?

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