Same here, as I stated it came with the car when I bought it. I'd just like it to work properly. To me it's a piece of mind thing. It's not hurting anything to have it. As for cooling down, yes.. I have a eclipse that's pushing almost 450hp which has had both oil and liquid cooling turbos on it. When I had the liquid cooled without the turbo timer I did find sludge build up in the turbo. This is back when I was daily driving the turbo. When I switched to a oil cooled and added turbo timer - no issues.
There's tons of different speculations as to whether or not you need a turbo timer and each opinion will have different reasons behind it but I see it a a cheap preventative that I'd rather have than not.
That being said, I'm still not sure why I can't get the turbo timer to add time when driving. It's set to H with 10 additional seconds. No matter what it always counts down from 10 seconds.. I made sure it is seeing a RPM signal and is reading it correctly. Any thoughts?

 

Was up everyone. i finally found this topic bc im having problems with my turbo timer as well. my problem is the same, it was working fine, but once i installed my aem wideband gauge then my turbo timer was counting up and it went all the way to 8mins. what do you guys think it is, did i touch a wire or something? i always have to turn it off while im driving but before i turn off the car i turn the timer back on.

 

started having same exact prob, anyone?

 

I turned mine to the 30 sec set time, I havnt messed with it in awhile. But now any time I turn the ignition off the car will continue to run for 30sec. Here is the greddy manual if this helps http://www.greddy.com/img/PHP/products/pdf/685.pdf