CLŽ

could/has anybody measured this?

i don't have the proper equipment. tried searching but nothing came up.

EricL

Yes, there is a temp sensor in the transmission. You can take a couple of "probes" (patch cords) to "get at" the transmissions temperature sensor’s two leads going to the back of the connector on the ECU. You need a Helms (the Acura Service Manual) (Note: if you really are serious about this and want to do this, I can give you the connector pin #s)

The temp doesn't show up on a "conventional" OBD II scan tool, so you need to get a calibrated reading of the sensor that is sitting in the tranny. The idea is to just buy the sensor from Acura (or borrow it from a tranny) and stick it in a pot of hot water with a thermometer to get an idea of how it responds with varying temperatures.

You also need to know the current that is going through the temp sensor (this presumes you want to measure the voltage of the sensor as the car is running in various conditions). The "hassle" part is getting a pin extractor to remove one side of the temp sensor to measure the current (you put a meter in series with the sensor to get the current reading). It is possible that a slip could set the MIL (malfunction indicator lamp), so you’d want to be careful and/or buy a cheap ODB II tool – or find a buddy – to reset your MIL lamp if it came on from the “tinkering.”

If you have:

1. The change in resistance vs. temperature of the sensor that feeds temp info to the ECU/PCM. (You put the sensor in the pot of water and watch the change in resistance)

AND

2. Know the current that is feeding the thermistor. (You put a meter in series with the temp sensor with the car running OR you get a hall-effect/current probe that can clamp over one of the sensor’s wires.)

AND

3. Put a couple of patch cords (into the back of the car’s computer connector) on the thermistor pins that are feeding the temp data into the car's computer.

YOU WILL HAVE ALL THE INFO YOU NEED!


I was going to do this, but there was very little interest in this data...

CLŽ

interesting, appears much more complicated than i have anticipated.

i have interest in this data for the relevance of an old topic: the tranny cooler. Although there have been raves about purchasing such an item, i wonder if it is necessary. knowing exactly what temp. within the tranny, we can conclude if such a purchase would be needed. in a superchaged application i can image the purchase would be ideal, however with bolt ons such as headers i doubt that temperatures would rise over the range of 200 degrees, and if it were to do so, i am assuming the stock cooler would be sufficient, even in stop and go driving such as myself (yay LA).

some measures i have done myself has been changing the fluid every 10k. whether it is enough i am not sure.

basically i am attempting to justify the purchase. i would purchase the cooler if needed, not for piece of mind, but rather functionality. no need to buy a cooler if its not needed. plus i would rather have someone who has more experience than i to provide the correct temperature numbers.

still looking for concrete numbers to indicate the need of a purchase for the tranny cooler. ideas? comments?

EricL

What you wanted to do, is exactly what was on my mind...

I even had a friend of mine do some prelimary work on a "data logger" (a dirt cheap processor to store temp data).

My take on this was: if someone could show ACURA that there box was runing rather hot, they wouldn't be able to complain about the addition of a B&M or Comptech cooler kit (basically a B&M tied through the stock ATF-to-coolant cooler/warmer).

If the ATF was sitting around 240+, that wouldn't be nice.

I left a message over on Comptech's board and called MikeB to see if I could get the "test" numbers on the temps, but I have a feeling that this is a touchy area (they need to work with Acura and, IMO, it would not help their relationship to publically dump some scary, high-temp numbers to the public). Want to call them again?

Someone said one of the guys who brought down a S/C equipped 6-speed said the cooler on the auto dropped the temp by 60-70 degrees F (???).

The temperature near the outside of the cooler was reported to be around 200 degrees F (that means that the tranny is hotter).

BTW, look at the size of that intercooler, and it's the size of 1/3 of a coke can. That's not a lot of cooling if your runing up a hill at WOT on a hot day (something to consider).

BTW2, adding a lower temp fan thermo switch and thermostat (do a search) would help remove more heat from the tranny. (The higher the delta-T, the higher the rate of heat removal. In other words, if you cool down the coolant, you will cool down the tranny and allow more BTUs to be transferred per unit time).

EricL

A tee tapped into the ATF line where the cooler would end up going, could be used to put in a cheaper temp probe (it just wouldn't be sitting right inside the tranny -- but it would be close).

This "trick" presumes that you are considering a cooler anyway, and putting a small substitute hose/barb is not going to be a big deal.

Here's an idea:

Put a really thin -- well, not too thin -- chunk of brass tubing in line with the ATF hose going INTO the ATF-to-coolant intercooler. GET A CHUNK of thermal sensitive tape and wrap it around the brass. Cover the brass with some insulating wrap and tape it over. Drive around and check the label to find that max temp reached.

Picture of the label:

CelsiStripŽ Temperature Recording Label



LINK: http://www.spirig.com/search/image/t...tor230volt.jpg

CaddyŠ

Warm enough to justify a Transmission Cooler....

Wires

Heat causes the ATF to breakdown. That reduces it's lubrication properties, and then the tranny dies. If you're really working the car (towing, etc.) then you'll probably want to put a cooler on it.

Since you're chaning the oil on a regular interval anyways, you are already solving your problem (if you had one). The cooler will extend your tranny drain interval.

CLŽ

the lower temp thermostat seems like an easy mod which i might consider. i'm going to research this more but generally could you adjust the thermostat to turn on the fans at a certain temperature such as 200 or is it non adjustable.

also the cooler extending the tranny drain interval makes sense in helping to prolong the life of the fluid. i am just making sure if one purchases the cooler that it doesn't get below 160 degrees.

CLŽ

hmm there is good info in the archive . anyways, scalbert has some measurements after the install, but i wonder if he has some before the install?

it appears to be working, the tstat and fan switch that is.

EricL

NO before the cooler install temp info (or so he said).

Also, the temp is measured outside the radiator (also mentioned at one time or another).

The fan switch and tstat seems to be working on a few cars...

You WOULD NOT want an extended period during warm-up where an external cooler prevented the ATF from getting up to temp. The B&M cooler will route the "thick" ATF (when cold) AROUND the radiator. An oversized ATF cooler without some kind of thermostatic control could be a disaster...