Looking for a timer relay

I have a turbo'd car that I'd like to wire the electric helper fan (15A) to run for about 3 min. after shutdown. I figured a timer relay like is used in alarms would work nice. Anyone know where to find such a thing? Thanks.Subtlety is EVERYTHING.

Thanks very much - I did a search and found this relay but it seems to only be 0-90 seconds. 3 minutes is a more optimal time - is there a way to modify it? Subtlety is EVERYTHING.

Check this one out http://www.elkproducts.com/products/elk-960.htm

I found that Hondas have a fan timer relay - I know where in the dash they are but nothing as far as how long they remain running, how they wire in, etc. I also have read that Mazdas do as well. ?! I did find a 528T but at $25 each, if I change anything internally in them (and I'm not real confident on my ability to do it correctly), I'm SOL if anything happens to it. But that's what I'll try if I can't locate an oem relay.Subtlety is EVERYTHING.

here is the one that royman is talkigm about about. HERE

Wow.....it looks like a Jaycar but 1-60 MIN? That'd be long enough - heh heh. Getting a used turbo timer might also do it (not on the ignition...just the fan). Thanks much. 6/13: CORRECTION.....its a 1-60 SEC timer, which puts me right back where I was. I need something thats 3-4 min.Subtlety is EVERYTHING.