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View Full Version : How bad? (get in car-boost-turn off)



biketsai
09-06-2008, 03:08 PM
I know that there has been a thread on this and ive read it a couple times. I was just wondering what are the lasting effects/initial effects of starting the car, boosting around 8psi right away, then coming to a stop 5 minutes later and turning the car off? What harm is done?

crono35
09-07-2008, 01:50 AM
Not sure exactly what problems you'll have by going immediately into boost, but by shutting off too fast you don't give the turbo enough time to cool down. Oil still remaining in the turbo may cook... but from what i've heard, this is less of a problem with better oil. In general you don't want to push a car until it's warmed up.

8 PSI isn't too horrible, but short drives like that may be a recipe for sludge issues down the line.

ILoveT
09-07-2008, 07:00 PM
You are not giving the oil the proper amount of time to warm up so the turbo will not be getting adequate lubrication.

mike-2ptzero
09-07-2008, 07:09 PM
You are not giving the oil the proper amount of time to warm up so the turbo will not be getting adequate lubrication.

You dont need the oil temps up, coolant temps are way more important. When the coolant temp is low the car runs in a "rich" tune.


When I run my car at the drag strip my oil temp gauge never even moves before I make a run, but I will not run my car unless my coolant temp gauge is straight up.

ILoveT
09-07-2008, 07:12 PM
You dont need the oil temps up, coolant temps are way more important. When the coolant temp is low the car runs in a "rich" tune.

Open loop...

And I still would be scared to run my car if my oil temps weren't up. Yikes!

mike-2ptzero
09-07-2008, 07:35 PM
Open loop...

And I still would be scared to run my car if my oil temps weren't up. Yikes!

Why, what do you consider to be temps for running your car?


Your gauge reads 150 at its lowest reading, so even though the gauge hasn't moved your oil could already be 140 degs. The oil/coolant exchanger allows the coolant to heat the oil, so if the coolant is up your oil temps are most likely up there too.

It isn't like the oil isn't doing its job to protect the engine even though the temps are not high enough to make the gauge needle to move. If it wasn't then your would have nothing but damage just from letting it idle.


Do you seem me scared to do it on a 600whp car that is moving at near 140 mph with low oil temp readings? [>_<]

biketsai
09-07-2008, 08:17 PM
Why, what do you consider to be temps for running your car?


Your gauge reads 150 at its lowest reading, so even though the gauge hasn't moved your oil could already be 140 degs. The oil/coolant exchanger allows the coolant to heat the oil, so if the coolant is up your oil temps are most likely up there too.

It isn't like the oil isn't doing its job to protect the engine even though the temps are not high enough to make the gauge needle to move. If it wasn't then your would have nothing but damage just from letting it idle.


Do you seem me scared to do it on a 600whp car that is moving at near 140 mph with low oil temp readings? [>_<]
Thanks Mike, at least I feel safer of when to "boost". But what about turning it off quick?

bassed
09-07-2008, 08:53 PM
Thanks Mike, at least I feel safer of when to "boost". But what about turning it off quick?

Drive to cool down or listen to a song for 3 minutes. Driving it to cool down in a regular fashion for 5 minutes is the easiest.

mike-2ptzero
09-08-2008, 07:42 AM
Thanks Mike, at least I feel safer of when to "boost". But what about turning it off quick?

You want the car to cool down for 1-2 minutes after getting out of boost, this can be done by driving easy like a cool down lap or just letting the car idle.

When I run the car at the track my cool down time is the drive down the return road, once I get to my pit spot I turn the car off.

Nebone
09-08-2008, 09:19 AM
Someone can always stall the car after running in boost. Any car manufacturer recommends to start the car and drive it right away. My girlfriend has a VR6 with 100k on it and the car can sit for days and she'll start it and drive right away (gives me the chills and I tend to yell then) but the car is fine. I tend to take care of the 1.8T w/ 131k+ by letting it drop to idle on cold starts and waiting few seconds to shut it off.

mike-2ptzero
09-08-2008, 09:32 AM
Someone can always stall the car after running in boost. Any car manufacturer recommends to start the car and drive it right away. My girlfriend has a VR6 with 100k on it and the car can sit for days and she'll start it and drive right away (gives me the chills and I tend to yell then) but the car is fine. I tend to take care of the 1.8T w/ 131k+ by letting it drop to idle on cold starts and waiting few seconds to shut it off.

Well letting the car idle to warm it up is just a huge waste of time and gas, plus all your doing is causing more polution. Driving the car easy is the best way to warm it up. Now revving he car up right as you start it up would be bad since not every part in the engine will have oil at that point.

bassed
09-08-2008, 10:38 AM
Well letting the car idle to warm it up is just a huge waste of time and gas, plus all your doing is causing more polution. Driving the car easy is the best way to warm it up. Now revving he car up right as you start it up would be bad since not every part in the engine will have oil at that point.

Very true, especially in winter. You do nothing for the Transmission at all by idle warm up. You need to drive the carm to warm it up properly in winter, hence why even most owners manuals for BMW's and Audi's recommend getting in and driving the car.

onemoremile
09-08-2008, 12:41 PM
It isn't like the oil isn't doing its job to protect the engine even though the temps are not high enough to make the gauge needle to move. If it wasn't then your would have nothing but damage just from letting it idle.



Oil doesn't really start working until it is about 150 F which is why the gauge starts there. Idling has extremely low cylinder pressures and the rings are pretty much along for the ride. Run a car hard before warming it up and you can spin a bearing, prematurely wear the rings or cylinders, and even wear the cam journals. Maybe you've just been lucky or maybe it is the short mileage but I'm surprised you haven't had problems with main bearings or losing compression.

One of the worst things you can do to a car is beat on it when cold. Synthetics help but they are made of magic and have a normal operating range of 150 to about 250-275.

If you take a look in the owner's manual it has shorter oil change intervals for severe driving. This is often described as frequent short trips. Long freeway drives show the engine almost no wear. The vast majority of engine wear is the first 30-60 seconds after startup.

mike-2ptzero
09-08-2008, 02:04 PM
Oil doesn't really start working until it is about 150 F which is why the gauge starts there. Idling has extremely low cylinder pressures and the rings are pretty much along for the ride. Run a car hard before warming it up and you can spin a bearing, prematurely wear the rings or cylinders, and even wear the cam journals. Maybe you've just been lucky or maybe it is the short mileage but I'm surprised you haven't had problems with main bearings or losing compression.

One of the worst things you can do to a car is beat on it when cold. Synthetics help but they are made of magic and have a normal operating range of 150 to about 250-275.

If you take a look in the owner's manual it has shorter oil change intervals for severe driving. This is often described as frequent short trips. Long freeway drives show the engine almost no wear. The vast majority of engine wear is the first 30-60 seconds after startup.


LOL, it must be that I am just lucky.[rolleyes]

I run nothing but Redline oil and do compression checks before and after taking the car to the track. Been doing that since I went 2 liter 6 years ago and have never had a loss of compression after a track day or while the car was in my hands.


Who said anything about running the car hard 30-60 seconds after starting the car? It takes longer then 60 seconds to get the coolant up to normal temps. The car doesn't need to sit at idle for 5 minutes just to drive the car.

Don Supreme
09-08-2008, 02:21 PM
Oil needs some temp to flow correctly..........

Also, Mike if you started your car up in 32F weather you would be a little more concerned about warming the car up correctly...

Nebone
09-08-2008, 02:41 PM
Winter is a different story.

Whats the demage if a thermostat opens too early and car runs at 60 degrees instead of 90 for a few months?

mike-2ptzero
09-08-2008, 04:29 PM
Winter is a different story.

Whats the demage if a thermostat opens too early and car runs at 60 degrees instead of 90 for a few months?

Could cause the car to run rich all the time.


Oil needs some temp to flow correctly..........

Also, Mike if you started your car up in 32F weather you would be a little more concerned about warming the car up correctly...



Yes. But it flows enough even when we first start the car and by the time the coolant temps are up the oil is flowing pretty good. This is when a oil pressure gauge comes in handy and something I have been running since going T28 back in 2001.