View Single Post
Old 11-08-2014, 04:54 AM   #9 (permalink)
jedi_sol
Master EcoModder
 
jedi_sol's Avatar
 
Join Date: Mar 2009
Location: Tustin, CA
Posts: 929

2013 STi *SOLD* - '13 Subaru Impreza WRX STi
Subaru
Sports Cars
Team Turbocharged!
90 day: 26.59 mpg (US)

1996 Geo Metro *RETIRED from Ecomodding* - '96 Geo Metro Base
90 day: 58.68 mpg (US)
Thanks: 368
Thanked 380 Times in 238 Posts
Quote:
Originally Posted by oldtamiyaphile View Post
I agree with the above, however, when you EOC, you run the turbo at high load/ boost and instantly turn it off. That's quite a bit different to the pulling into a car park scenario where you'll be driving for at least 30 seconds off boost. I don't think any OEM's are testing their turbos for EOC conditions.

Moreover, it's not only the cooling that's the issue, it's the potential for starving the turbo bearings of oil (turning the engine off while the bearings are still spinning.
Yes, very valid points.

After doing some research on other sti forums, it seems modern water cooled turbos and synthetic oil has virtually eliminated the "coking" issues. The general consensus is:

"Cooldown: Zero unless I was going full boost right before I stop. Then I will idle it 30seconds+
Our turbos are oil and water cooled and will continue to flow water through a clever convection mechanism with the engine off so long as the turbo remains warm. That, plus running synthetic oil virtually eliminates the coking problems old turbo cars had. Again, read the manual; the car does not need a cool down period."

With that in mind, if I romp on boost, of course I will not EOC right away. However 90% of the time, I am far from using boost during my daily commute. Also, before I push my kill switch, I let the car coast at idle for about 5 seconds, therefore it's not a "hard" the shut off.

So I guess it just depends on the kind of turbo you have.
__________________







See the rest of the Sti project log:
http://ecomodder.com/forum/showthrea...log-26612.html

Last edited by jedi_sol; 11-08-2014 at 01:32 PM..
  Reply With Quote