Project Reality Forums

is their a way to change the grenade time when you hold the grenade for a couple seconds it explode faster

No. You can only change the throwing strength by using the right mouse button, but you can't cook it.

As if PR players needed any more ways to accidentally suicide / teamkill with grenades.

You used to be able to cook a lot of things

you can however;
russian RGO: detonates on impact(also refuses to detonate on some maps)
throw from farther distance: less sizzle upon contact and faster detonation