I have just installed the star stage 2 on my car, my question is... If I don't have a turbo timer yet, how long should I allow the car to idle after hard driving in order for it to properly cooldown? 1-2mins? Also if say I didn't boost within the last 3-5mins of driving would that cooldown time be shortened?

I personally don't even turbo time the car if the last 5 minutes of driving were a light cruise. I really only turbo time (3 min) if I've had to boost within a couple minutes of parking. I use Mobil 1, water cool the turbo, and use an oil cooler, so I feel pretty safe. Last time I dissassembled the turbo, all of the bearing surfaces looked clean.

Corbin

'95 ESI-T
Now with more power and fewer leaks



Gimme fuel...Gimme fire...Gimme that which I desire

Yeah... the only reason to "turbo time" is to prevent the remaining oil from coking up inside the CHRA. This only happens when the turbocharger is extremely hot and therefore you need to keep oil flowing through the CHRA a few minutes until it cools down.

water cooled CHRAs dont coke anyways, so while your turning into your parking space or whatever the turbo is being cooled.... dont time it at all

That's right. Water-cooled turbos don't coke up. Every 2GNT turbo conversion should incorporate water cooling the turbo. It's a shame that most of you don't, especially considering how easy it is to access the cooling system in a 2GNT.

I think you all will find this graph very interesting:



The graph above shows the turbocharger bearing temperature leading up to engine shutdown and for 20 minutes following shutdown. The temperature is displayed relative to the coking threshold of high quality mineral based oil.

As is clearly evident, the old fashioned non water cooled turbocharger operates above the coking threshold when under high load and experiences a very high temperature increase through heat soak immediately after engine shutdown.

I personally just do an automatic 30sec countdown, sometimes it is a minute if I am travaling long distances 30min or more. That's pretty much it but I do use mobile 1.

I typically wait till my Egt's are below 1000 deg F. I would like to eventually put the waterlines on my turbo though.