dgeesaman

iTrader: (7)

Adam_c, DamonB, you're just trying to prevent a temperature spike from heatsoak, right?

So the real judgment is whether your method keeps the water/oil/engine temps no higher than operating temperature following the run, and letting the engine cool slowly from there. Cooling the car too quickly is also bad, isn't it?

Dave

DamonB

My coolant temp sensor is in the tb line. I find that the heatsoak of coolant is not near what most claim.

As for the fan mod the hood is already up. Running the fans doesn't help anything as raising the hood has a much greater effect in getting the hot air out of the engine compartment.

DamonB

Uhhhh, the fans turn on all by themselves when the coolant gets hot. If the coolant isn't hot I don't need the fans running.

My argument is that your inference that my car runs at a differing temp (hotter or cooler) for any reason compared to yours is completely unfounded as the two cars have never been run under the same conditions in the same location. Outside temperature, relative humidity, how hard the car is actually run etc all have profound effects on coolant temp. I don't have nor have I ever had overheating problems with this car. If the car isn't overheating and I can control temps just fine why do I need to be worried of anything else?

As for the fan mod the car already has the recall box in place. If the car is that hot at shutdown the ecu will run the fans all by itself. If the fans aren't on, they don't need to be on. You're going to cook stuff under the hood given the fact that you drive the car.

DamonB

Nothing exotic; just any sprayer from the hardware store is fine. It just comes down to how much water you wish to carry. I think mine is 2.5 gallons. I made do just fine with a 1.5 gallon but now that I have a codriver I use twice the water and also have to cool the tires if it is really hot outside. I don't shoot a large volume of water on it, just a fine mist for a couple minutes.

DamonB

It could be but honestly I don't think you'd be capable of that with just a water sprayer. Unless you actually start hosing the engine down with a hose I wouldn't be concerned. The water sprayer is only cooling the coolant more quickly and not instantly cooling off hot metal parts.

Air cooled aircraft engines are capable of being cooled too quickly, it's called shock cooling. This happens when the engine is at temp and all of a sudden the air temperature drops greatly due to an atmospheric change at a different altitude. The observant pilot will notive the change in outside air temp during his descent and make a slight power change.

FYI I only use the sprayer because at autox I must since I don't get cool down laps. When at the track I have no need for the sprayer as I much prefer running a couple cool down laps. This actually pushes air through the radiator and oil coolers as well as around the brakes, exhaust, engine compartment etc. I much prefer a cool down lap as it does a much better job at getting the parts cooled off. OTOH autox isn't really hard on brakes either, all you really need cooled off is the engine.

SWAT81

iTrader: (14)

Two words my friend, "Turbo Timer"

adam c

iTrader: (2)

My goal is to keep the engine temps from getting any higher than they need to be. If I run the fans during the run, the temps will be cooler when I exit the track.

KevinK2

point is you will not see he ususal so called 'heat soak' spike in the tb line, and more importantly, the spike seen in the t-stat housing is local, and does not reflect general coolant temp.

fan mod note was general, for parking lots at work, malls, etc, where hood must stay closed.

1QWIK7

iTrader: (33)

^^exactly

that is what everyone missed

adam c

iTrader: (2)

With that reasoning, you don't need the sprayer either

My arguement is that running the fans during your run will keep the temps from rising as much as they will without the fans, regardless of conditions. You obviously take serious measures to insure that you car cools quickly after your run. I can think of no reason not to run the fans during the run, and you have not provided one.

Same arguemnet as earlier. If the fans aren't on, and they don't need to be on, why spray?

adam c

iTrader: (2)

Friends don't let friends install turbo timers

DamonB

Because there is not much time before the car has to be run again and in this case time is the real enemy. Spraying the radiator gets the coolant temp down in less time than not spraying it. The coolant gets just as hot when run but spraying afterwards gets the car cooled off more quickly so when it's time to roll out in a few minutes with Driver #2 and it's 100 friggen degrees outside the car is ready.


That's not been my experience.


Shame on me then! How about I don't need to run the fans all the sanged time? Turning the fans on manually doesn't hold temps down in my experience unless you're willing to keep the coolant too cold IMO, like under 190F. Is there some sort of self inflicted shame I'm failing to realize since I refuse to believe the car needs more help in cooling for my use?

Is swatting a fly with a Buick better than a rolled up newspaper?

DamonB

As you pointed out the heat spike in the thermostat housing is local only. The tb line doesn't heat soak cause it's isolated from the hot metal parts of the engine and with the engine off (coolant not circulating) the tb line would diplay temps lower than the block. My findings are that true heat soak of the coolant trapped in the motor is not near as great as most believe. I typically shutdown at the track between 190-200 and the car sits for anywhere from a few minutes to half an hour. After sitting the temp of the coolant in the tb line where my sensor is located would certainly be less than what's in the block since the sensor is effectively isolated without the water pump running. When the car is started back up I would expect to see the temp on the gauge quickly rise to a slightly higher reading as the hot coolant is now circulating past the sensor and then fall again as the coolant in the system equalizes. I shutdown under 200 and no matter if the car sits seconds, minutes or hours I don't see any real heat soak of the coolant that alarms me.

As a for instance this past weekend the car is shutdown at about 190. 10 mins later the key is turned on and the temp gauge reads about 190. Immediately after startup the temps rises to 195 or so and then after less than a minute of engine running drops back down to 190 and stays there until the car is run hard.

Again, my car already has the fan mod as the recall was performed, I don't see a need to run it more often. It is my opinion that running the fans at lower temps after shutdown really isn't needed as I don't feel that small difference has any impact on the life of the parts under the hood. That's my opinion and people are welcome to theirs but I challenge anyone to provide proof of prolonged life by running the fans more often. Sure the car with the fans running will cool parts under the hood off faster but does that equal a real benefit to part life? Seems to me if the parts were that fragile driving the car hard and having them at any temp extreme would kill them anyway. If they're going to have their life shortened by being under the hood with a twin turbo rotary wailing away at them I don't think a few extra minutes of fans running after the car is parked will have any great effect on their reliability or lifespan.

adam c

iTrader: (2)

I'm not saying that you shouldn't spray. I think its a good idea. Since time is important, it makes sense that the car will cool more quickly if it comes off the track cooler, and that is what running with the fans will do.

It sounds like you have not tried it.

I like my coolant temp to be around 195 to 200 when I start my run. By turning the fans on at the start of the run, my coolant temp will not increase very much by the end of the run. Since keeping temps down is important to you, I would think that this would be something that you would want to have on your car. The cost is minimal. Installation is easy. You can easily remove it if you don't like it. You can leave it off when you don't want to use it. I just don't see ANY negative from trying this.

DamonB

Acutally I have tried it and that's why I'm so adamant on what it can accomplish. All you have to do is pull the a/c relay from the relay case under the stock intake crossover duct. This will let the radiator fans run with the a/c switch on but not allow the compressor itself to run. I've done it on roadcourses and at autox sites and my findings are that it doesn't help unless you're willing to overcool the motor, so I haven't bothered for a long time. The motor is still going to get past 200F degrees minimum when run hard whether the fans are running before hand or not and cooling it afterwards will take the same amount of time. The only exception would be if your run was so ridiculously short that the coolant never had time to really get hot and I've never experienced that.

I realize some may have trouble following my simple logic but I don't understand the need to try and "fix" a problem I don't have at present.

adam c

iTrader: (2)

So I have convinced you right

Perhaps my Fluidyne, when combined with running the fans, is more effective than your setup. I don't normally see much of an increase in coolant temps after a hard autocross run ......... usually around 50 seconds where I race.

J.S.J

I really don't know how you guys can drive hard without having a fan on your oil cooler. I know some guys have larger coolers and thats fine but I have a stock cooler with a fan mounted to it. The fan cuts down the temp. It just makes sense to have some control when your stuck in traffic etc. Theres not much room but it can be done and is well worth the time.

DamonB

I would make the case that if you're just sitting there stuck in traffic that the oil isn't getting too hot. Can you make it cooler with a fan? Probably. Do you need to make it cooler? No.