looking to get a manual fan switch to run when my car is turned off, waiting in the lanes at the track. already have a 160* t-stat and have the computer appropriatley re-programmed.

was looking at the SLP and Casper's switches on ls1speed.com

SLP advertises the ability to retain stock operation when not in manual mode
Caspers advertises a 5-10 minute timer when set to manual-HI mode.

so far, the Casper's seems more ideal for me, because i'd feel better being able to set it to manual mode with the 10min timer and then walk away and not have it kill the battery if i walk away for too long.

my question is whether or not the casper's switch retains stock operation like the SLP switch?

 

The more adjustable and tuneable one might be the better bet.

 

I have the slp fan switch. I purchased it for the same reasons you want one for. I think I used it about 4 times and the switch broke.