creating a delay before relay turns on

basically you need a relay for your relay.  use a DEI 528T pulsed timer.  the timed output is completely adjustable. it is just like a normal relay with a timer.  when it triggers terminals 30 and 87 are energized for as long as you wish depending upon how much you have adjusted the adjustment screw.  you need to hook up this one to another relay.  on your second relay energize terminal 85 with ignition power and then connect terminal 86 to 87A of the 528T.  connect terminal 30 of the 528T to ground.  this way after the 528T times out for the preset time it will send ground to 87A and down to your second relay turning it on. 

Delayed trigger relay drive You can try wiring up the circuit in this prior post, you probably won't need the inverter shown if you plan to drive it with with a positive signal.