Project84

iTrader: (2)

I see your logic here and you're correct BUT, there is some room left for interpretation in my opinion.

I agree even w/ a turbo timer the engine still must turn off eventually and the engine will still get heat soak and "be the hottest time for an engine" BUT:

where I see my friend's setup being beneficial is w/ his adjustable fan switch, his fans can be set to come on at any operating temp, I believe his are set near 180. So in his situation, w/ the fans pulling air through the radiator (and the coolant hot enough to still be circulating through the engine via an open thermostat) he is cooling his engine marginally before shut-down, thus giving lower temps on shut down and w/ lower temps you will get lower temps from heat soak "a few minutes after the car is shut off."

Now, I just typed all that because I don't like to be wrong, and I'm too stubborn to give in.... but I do agree with your logic as well, and I hear ya loud and clear. I still want one. Call me a ricer.... I think they're cool.

DazedandConfused

iTrader: (4)

turbo timers are pretty popular in the audi population for a quick and very cheap part to purchase.

and im kinda stumped why they would invent a turbo timer and it become such a huge popularity with turbo cars for it not to have any purpose.

and i was pro turbo timer for a bit until i came across a google website with this advertisement.......

Turbo Timer, Body Kits, Lambo Door Kits! (and then i changed my mind)

Sam Amporful

iTrader: (13)

You dont need it. while a miata is moving, the water temps are much cooler in the engine than what they'll be at idle. The car gets hotter at idle just sitting there. Its better to shut your car off after street driving and not just let it sit there. If you shut off your engine off after 3min. of idle, your coolant temps are at about 195-212*. If you shut it off right after a normal drive, it should be somewhere around 160*. oil just gets hotter with a sitting car because theres hotter coolant to flow. If you're worried about the turbo cooling and good oil circulating through the turbo, why dont you just get an oil cooler? That'll be more effective than a turbo timer and you should feel just fine shutting it off right after a drive since an oil cooler cools the oil as you drive.

Project84

iTrader: (2)

Google says OEM Miata thermostat is 195*F. So you're telling me while driving your miata the temps are 160*F? I think you should replace your thermostat.

I'm probably going to run an oil cooler after that thread came up today w/ links to different ones... that's actually what got me thinking about a turbo timer.

Sam Amporful

iTrader: (13)

Thats the temp at idle while the car isnt moving. Thats the temp that the fan shuts off too. The car actually idles 195* full heat for like 10-12sec. anyways by what my gauge tells me. Fans turns on at 212-215*F. mine is actually lower than 160* while moving since i have altered ways to lower moving temps. It depends on the weather too

Project84

iTrader: (2)

I'm no expert but I would think your car would run better around 190-200*F rather than 160*F, if it's that cold does it ever make it into closed loop?

FRT_Fun

iTrader: (19)

When I finally get my turbo on this summer there will be no turbo timer.

Does anyone even know at what temp the oil will start doing damage if the car is just shut off?

If your cooling system is good enough to keep the car cool while at idle, then it is good enough to keep your car cool while driving on the streets. I see the only benefit being the "cool" factor for those that enjoy that.

Sam Amporful

iTrader: (13)

No. You always want your water temps as cool as they can be. Hot water doesn't help dissapate heat very well.

what? im only talking about water temps here

skidude

iTrader: (3)

Foolishness.

sixshooter

iTrader: (12)

The water temperature is a red herring. You obviously don't use a timer to let the engine cool down. It is to cool the CHRA. After you have been cruising at 4000 rpm on the interstate for a while and pull into a convenience store to take a whiz and grab a Slush Puppy, your turbine housing could easily be 800+ degrees. Automotive motor oils have flashpoints between 350*F and 440*F. Synthetics are a few degrees higher. Is it possible that the oil in the CHRA will reach a temperature high enough to cook off some the base oil? Yes, very possible. And no, you don't need to be boosting for this to occur (another myth). But boosting does exacerbate the problem through the increased generation of heat.

If the significantly reduced volume and temperature of the exhaust gasses passing through the turbine housing at idle doesn't allow the housing to run cooler than at a 4000 rpm cruise, I'd like a detailed explanation as to why. The idea of a shutdown timer was devised because factory turbocharged cars were devouring CHRA journal bearings and seals at a ridiculous rate back in the day. The primary cause was oil coking and the associated production of solids and acids that chemically and mechanically ate journal bearings and seals. And to provide an obvious answer as to why production vehicles are not equipped with shutdown timers: liability.

The production car solution was a band-aid called water cooling. And yes, it mediates, but does not solve the problem. There is no complete replacement for actually allowing the CHRA to gradually cool to a reasonable temperature before ceasing fresh oil supply.

I am guessing that a lot of the animosity towards shutdown timers on this forum is because the ricers are fond of them. I understand that reasoning completely. I detest doing stupid things for show or just to be cool. If I wanted to be cool, I would not have bought a Miata. But even a dumbass ricer can have a useful part on their car even if they don't know how it works (ie; how many ricers can plot their turbo's compressor map?).

Good luck all.

gospeed81

iTrader: (51)

Thanks for that six.

I commute 100miles to school, and always wondered about this. All the threads I read said I was a dummy to think I needed one (my turbine housing has to be HOT after that much time on the highway), and that I just needed to drive slowly for a block and let it idle while taking my seatbelt off.

I don't want to install a turbo timer, but would like to know just how long it takes to cool down the CHRA sufficiently after an hour and half highway cruise (with some boost) that ends with 15min of city driving (with some boost).

Project84

iTrader: (2)

Turbo Diesel guys set their timers to like 15 minutes, whereas my friend w/ his supra has his set to 1 minute, but if he's been driving long distances or being hard on the car he'll bump it to 2 or 3 minutes and then get out. Not sure what the exact answer is but, obviously a turbo diesel will be in boost a lot more than a turbo gas engine, so I can understand them prolonging the shut down.

I'd say after an hour and a half (and i'm totally guess) I'd let the car idle 3 to 5 minutes just to be super safe. Idling uses anywhere from .25 to .5 gallons of fuel per hour, so idling for 5 minutes might consume like .03 gallons. I know the idle GPH in my Saturn (not relative here at all... but just for sake) is .32 when warm, about .45 when cold. I have a ScanGauge II installed in the car, so I can read that in real time.


I feel validated, in a "go ahead, RICER" kind of way. Thanks six.

skidude

iTrader: (3)

What about an auxiliary electric oil pump that would run for 10 minutes after the engine was shut off? May not be feasible for us but the OEMs could have done it... it would provide fresh oil without creating additional heat.

Project84

iTrader: (2)

Like these?

SUPER sweet idea. Turbo timer for the system is an additional $50 and circulates oil for an additional 90 seconds.

Electric Oil Feed and Scavenge Pumps

I might...

sixshooter

iTrader: (12)

Ski, that's also a very good idea. It is a bit more complex and costly than the timer for an aftermarket solution, and maybe the expense is the problem for the OEMs, too. They probably just need for most of the turbos to make it out of the initial warranty period to make the accounting come out right. If they will go to the lengths they do to save a dime, why would they add $200 to the cost of every turbo car? That's my guess on that.

With regard to how long to set a timer, logically, anything will help. Obviously there is a point of diminishing returns with anything. Fifteen minutes seems extremely excessive. I would say between one and four minutes would be a reasonable help. Three minutes seems like an eternity once you've locked up your car and walked away. Excessive heat will dissipate relatively quickly once you remove most of the heat going into the turbine. Think how quickly a red hot turbine stops glowing red after the dyno pull is over. It is still hot, but the difference between its temperature and ambient is growing smaller as it cools, so as the temperature falls, it continues to fall more slowly. Call it diminishing returns. So then the first minute or two would be the most critical, and less so after that. Again, anything helps better than doing nothing.

sixshooter

iTrader: (12)

That timer controls their $225 pump plus you need the plumbing hardware. Figure $300+ for that setup if you want it.

Project84

iTrader: (2)

Hey, I only said I might... lol

I'm a tight-wad, fabbing my own hand-me-down IC hardpipes to avoid the expense of couplers or buying a new kit from CXRacing, fabbing my own downpipe and 2.5" exhaust, likely adding injectors to my intake rather than buying bigger ones for the stock location... I'm a cheap-o.

I just did a search and came up w/ that stuff and thought it was really cool.

elesjuan

iTrader: (11)

Call me skeptical, but I don't buy that. I will tell you right now that I very well could be wrong, but I don't believe it without proof. That just seems WAY over-exaggerated that a low load 4000rpm cruise on the highway is going to get turbine temps up to 800+ degrees.

Anybody have a pyrometer hooked up to their megasquirt with logs?

Ski, that's also a very good idea. It is a bit more complex and costly than the timer for an aftermarket solution, and maybe the expense is the problem for the OEMs, too. They probably just need for most of the turbos to make it out of the initial warranty period to make the accounting come out right. If they will go to the lengths they do to save a dime, why would they add $200 to the cost of every turbo car? That's my guess on that.[/quote]

Again I think this is an EXTREME over-exaggeration on cost. I've seen the inside of a "Greddy 200$ Turbo timer" and it contains about 15$ in electronic parts. Remove the display and buttons and you're looking at $3.00 of electronics. VERY Easily integrated into the software / hardware of modern CANBUS ecus.. If it was needed, they'd do it.

For ***** sake, I mentioned the Veyron.. thats like a 2 MILLION dollar car... Do you think they'd skimp out on a "200$" timer if it was really needed???? No.

albumleaf

iTrader: (7)

Nobody has mentioned that turbo timers make it even easier to steal our cars?

Project84

iTrader: (2)

I don't understand how you think a turbo timer makes it easier to steal a car....??? I'm a bit lost in trying to figure that out.