Jump to content
Ultimate Subaru Message Board

Turbo Timer Question...how long?


Recommended Posts

I am going to make a turbo timer, well sort of...how long should the engine run to cool off the turbo?? I have heard 1 min and 5 min. Any input? after this is proven to work for me I will give details on how this works

 

eric

Link to comment
Share on other sites

I know that there is this one that newscooby runs in his WRX...it computes driving time, engine temp i think, and tie sitting idling, and it has a constant display on how long it will run before it shuts off....i think the average is about 45-75 seconds...

 

On a turbo car with no oil cooler, I dont belive in T-timers. The oil just does not get cool only running thru the pan at idle. The WRX's do ahve a cooler...it runs thru the rad. So the oil, in theory is around 180-195 deg. However...temp at the pan on the EA82T is about 220-240....hm. Sit and idle, it will get warmer and stay there no matter how long it runs.

 

Now, Ive got an oil cooler adapter for sale....its $35 shipped....if you want it.

Link to comment
Share on other sites

I run mine for about 1 min 30 sec, the subaru glovebox manual states and I quote:

"It is highly recommended to let the engine idle for one minute after heavy hightway driving before shutting it down.

Idling for one minute before shutdown of the engine helps to assure maximum performance of the turbocharger for years to come.

This one minute period of idleing allows the turbocharger to stop spinning and cool down while oil is circulated through the turbocharger by the running engine.

These percautions are common practice in the industry with high performance turbocharged engines."

 

So there you have it from the horses mouth.

 

Good luck

Link to comment
Share on other sites

WJM, correct me if I'm wrong here, but I think that a car without an oil cooler would still benefit from a turbo timer. It isn't the oil itself that needs to get cooled off before shutdown, it's the turbo and its bearings. The purpose of the turbo timer is to prevent (I think this is the term) coking of the oil that is in the bearings, caused by the bearings being too hot. An engine without an oil cooler might take longer to cool down the turbo, but it would still happen, thus preventing the problems caused by shutting down a hot turbo.

Link to comment
Share on other sites

Take this into account.

 

Our turbo's are also water cooled. Water is a much better heat dissapater (sp?) than oil. So allowing the car to idle a bit before shut down allows the coolant to cycle and pull the heat out of the turbo bearings. It also keeps the oil circulating through the hot bearings, not allowing it to sit and burn. If too much burnt oil is present in the bearings, they begin to wear quicker. Eventually this leads to making the turbo ineffective. Most people call this process "coking".

 

So, i feel its not about the hot oil, but about the hot bearings.

 

My $.02

 

I run 30 seconds standard on my RX, occasionally she gets more if I deem it neccasary. Sometimes even less.

Link to comment
Share on other sites

AH tex you are right on line. well evryone is.

 

WJM that was a great set up for an oil cooler sale. Thats a good thing as I have one of those adaptors all set up on my car from you. It now runs cooler on a day like today with close to 100 deg. temps and the A/C on.

 

as for my turbo timer it is also a boost guage and knows when you have been running hard. It alters you idle time off of that. I make a lot of short trips so my base setting is at 30 sec. after a good drive I may see closer to 60 sec.

 

yes coking is the term.

Link to comment
Share on other sites

I aggree with not shutting it down right after driving...the driving that my two turbo cars experince is 50 miles worth of interstate, 75 or more MPH (3500+ RPMs), followed by what I call a cool down...i come off the i state...and on average, sit about 1 min at a stoplight to turn left from the off ramp..then its an easy cruise thru 4 stoplights in slower city-like traffic...than at 10-20 mph cruise thru my little neighborhood...then about 30 more seconds gently pulling into the garage, or into a remote parking spot....so in my situation, i don see the need for one...plus I am always mindful of the issues with turbo temps and what it goes thru everytime i shift, or mash the gas and left off for no real reason.

 

Now for someone who drives on the insterstate, comes off, has an immediate right turn, then into a parking and bam you are there...then i see a real need to let it cool...it hasnt had a chance to!

Link to comment
Share on other sites

Actually...ive got the current new one sold...so you have two options...you can have my used one for $20+shipping...OR, if you can wait about a week longer, I will try to get you a NEW one, if I can find one...still for $35 shipped.

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share

×
×
  • Create New...