What is the trick on "increase" the "%time" on collision ?

I test it in my game, the %time parameter on the onCollision callback is so "small" , negative.

the minium value was -11.xxx

But I see that the value on the "space scroller demo" is "bigger"

the minium value was -1.xxx.

How to achieve this ?

I know that the %time is meaning of the "time pass" after collision.