lexus114

Ya know, I really like your idea re; the led inside so you know when their on. But are those computer fans able to deal with the elements of the outside?

salimshah

^^ No.

But as long as they are setup, not to cause a short/fire, it may not matter if they keep dying.

The other thing to keep in mind is that they may impede the flow of air [when they die and when they tend to push the air at lower rate, as compared to the ram effect]... remember the fan-clutch on the belt driven radiator cooling fans...

Salim

lexus114

yep,sure do.

UNOHOO

iTrader: (3)

what if you scrapped the fan idea all together and simply add more surface area for the heat to dissipate such as through heat sinks. If you think about a heat sink on a processor in a computer its basically just a chunk of metal designed to give the most surface area possible for its volume, then once that is in place it is supplemented by air flow from a fan. You already have air flow from when your driving and even when you stop its still more surface area than prior to this mod. Not to mention there would be no need to wire anything up and no maintenance basically. Heres a pic of a hardcore computer heat sink just to kind of illustrate what im talkin about:

lexus114

well,here`s the deal.the reason i want a fan hooked up to activate only when necessary,is because the trans (on mine anyway) only get`s real hot during the summer time. I know this because,, when i actually feel the trans pan after driving in cool weather,it`s not hot at all. I can leave my hand right on the pan,that`s how cool it runs in cooler weather.So,that`s why i dont want to just add extra cooling capacity,or have a fan going all the time. It would actually not run warm enough. Great for florida people maybe,but certainly not up north here.

UNOHOO

iTrader: (3)

ok that makes sense, im actually not too far south of you, ill be living about an hour south of carlisle pa so similar weather in less than a week (thank god). Anyway so what if we were to devise a system that was removable? so once the outside temp reaches a certain point, attach the heat sinks, once it starts getting colder remove it, so you only have to mess with it twice a year.

The thing with the fan idea, depending on what kind of fans youre using, if you went with computer fans, i dont think theyre going to be doing any benefit once you reach a certain speed because the incoming air flow will be greater than the rotation of the fan and thus be providing no benefit. I could see it being VERY handy and effective at stop lights but over a certain mph (my guess is very low) it would be rendered ineffective.

One way you could counter-act this would be to rig up a way to shield incoming air from hitting the fan and the air flow delivery system (aka a tube) from blocking the existing cooler, at that point i think you would be able achieve what youre after.

I like this, its kinda like virtual engineering lol

code58

Lexus- I can't honestly answer that question for you because I haven't used them yet but my idea was something inexpensive, effective and low profile and I believe they would meet all 3 of those criteria. We know that cooler mounted fans are very effective at controlling trans. oil temp. They don't even have to be in the ram air stream for cooling as long as they have a fan that has adequate CFM rating. I don't know if the RX has trans. temp. output from the OBDII port, but if it did it would be interesting to use a Scan Gauge and see how effective the computer fans are at lowering the temp under adverse conditions. I'm betting that they would be adaquate (2 of the 5in.) because it doesn't take a 2k CFM fan to move the air away from the cooler and take the heat with it. I would probably, to start, use 2 of those fans, a relay and an inside LED. The relay and a switch to shut them off when you had the air on and didn't feel you needed the fans (such as open road when you have plenty of ram air), but wired to piggy back off of the cooling fan that comes on whenever the A/C is on. The parts are cheap and you never know unless you try. They certainly have fans that are made to mount on tranny coolers but I don't know if 1 would fit in the narrow space that you have. I like trying things and have always been gratified when you can solve a problem. I believe these fans also have ball bearings, not bushings. If the fans can be mounted so that they are pullers or pushers (depending on whether mounted front or back) with the blade toward the front so that the motor would be shielded from water and such, I believe it would be worth a try. My brother has a new Dodge with a Cummins and a 30 ft. 5th wheel and I wanted to mount a couple on his tranny cooler and use a Scan Gauge to monitor trans. temp. How many of you know what a "Scan Gauge" is? I have 1 and absolutely love it.

thomas1

I have a scanguage on my Ford F150 and it is great, I monitor the tranny temp and all of the other features. I used it for towing and monitoring water temp since I removed the mechanical fan and put on a Lincoln Mark VIII fan with DCcontrols. controller. I dont think the scanguage has been configured for the Lexus temp, but maybe I will hook it up temp and see what it does read. I know they are constantly updating the software to accomodate the needs of customers.

code58

Hi Thomas- I think it would depend too on whether Lexus configured the computer and OBDII to output that information. I wish I had known that my brother was going to travel on some of the roads that he did on a recent 2 month trip he and his wife took. He likes to take back roads (explore and enjoy the scenery) and in Colorado was on a climb on a narrow 2 lane road that he said was about a 15 degree climb for about a half hour. Once he started he was committed (no way to stop or turn back) and at full throttle in low gear was only able to do about 15MPH. I would have loved to seen what that tranny temp was. He said He figured if the tranny took that and didn't blow it could take about anything.

mikey00

When I checked with Scanguage a few months ago they didn't have the Lexus trans temp available yet and I didn't get the feeling there was any priority to do so. Being that we already have the trans cooler in the fender well plus the one on the bottom of the radiator, I am not sure additional cooling is going to be of any help. I was real interested in monitoring tranny temp awhile back and was close to ordering a sending unit with guage. But since then my tranny failed and I now have a new tranny using Mobil 1 so I kind of lost interest.

thomas1

You are using Mobil 1? How is it working, is there any quirks that you have noticed.???

code58

Mikey- Though I agree that Lexus has put more than adequate trans. cooler capacity in the RX, I feel that the placement of the fender cooler almost defeats the purpose of having it, because of poor air flow. The cooler is a nice cooler, but it doesn't get the airflow over it to get the benefit that it should produce. Simply moving air across it would correct that problem, in spite of it's poor location.

lexus114

You say their is also a cooler @ the bottom of the radiator?

mikey00

Yes. Plus you also have the A/T temp light light. I have never been able to find out what temp this light is set at but I have never heard of anyone having this light come on no matter waht type of towing or driving conditions. Another sign that maybe the trans is not running too hot.

mikey00

I agree it is not the best place for air flow, but maybe it's not really needed. It would be interesting to mount a remote thermometer on it or even just inside the fender well area to see if any excessive heat is being produced.