Automatic Transmission Fluid Cooler. ??

[Lunatic]

I installed the Mishimoto fan cooled transmission cooler, mounted it to the left of my engine oil cooler. I went from the stock cooler to the new aux cooler then back to the transmission. On track my transmission temps now stay below 225 degrees. I found air flow to be good enough and the fan pretty much worthless unless parked. All in all I am real happy with this.

[86SPEED]

On the last session of the day at my last track day, SOW, it was kinda open as almost everyone left.. it was very hot that day, 115 or so, and about 15 mins into it my trans light came on stating i over heated it. Until then i honestly didnt know about it. No one ever said anything about the Auto trans before over heating. thats been my last track day, and its going in next week for a full flush since i hit 30K and now it has a supercharger on it. Thats why im very interested in a cooler. Everything i researched made it seem like a pump was necessary and why they have been out of my price range for just a cooler. front of my car is also pretty cramped with a intercooler, SC oil cooler, engine oil cooler, condenser and radiator.. ill be getting under there and looking at where i can mount a small Setrab underneath with maybe a small NACA duct to it

-Thomas

[Freeman]

Where I plan on mounting mine will be the passenger side fog light area. Something like the new AVO oil cooler

[Tye300]

Originally Posted by Lunatic

I installed the Mishimoto fan cooled transmission cooler, mounted it to the left of my engine oil cooler. I went from the stock cooler to the new aux cooler then back to the transmission. On track my transmission temps now stay below 225 degrees. I found air flow to be good enough and the fan pretty much worthless unless parked. All in all I am real happy with this.

How did you route the temp sensor to your cooler?

[Lunatic]

Originally Posted by Tye300

How did you route the temp sensor to your cooler?

I installed the cooler and fan switch myself, but had a professional shop do the cooler lines. They also at my request dropped the pan and modified it to take the screw in temp probe.

[Tye300]

Originally Posted by Lunatic

I installed the cooler and fan switch myself, but had a professional shop do the cooler lines. They also at my request dropped the pan and modified it to take the screw in temp probe.

Thanks!

[Sithspawn]

Update: I got a chance to do a mountain run today, but there were quite a few people going up the mountain so I didn't really get much of a chance to do a lot of spirited driving. For the short amount of time that I did have an opportunity to get on it, the temps did shoot up quite quickly.

According to my logs, I got 2 minutes and 15 seconds to open it up and drive at 7 tenths on a 5 - 6% grade uphill section with a few good turns. In that time, the transmission outlet temps went from 217 degrees up to 235 degrees. The temps from the factory cooler started at 212 and ended up at 223.

The interesting thing is that it took 38 minutes going an average of 40mph in traffic for the temps to get down to a more reasonable temperature of 212 degrees. Basically, once I got to the top of the mountain and had been driving for about 10 minutes, the temps came back down to normal.

Now I will say that "spirited driving" is rather vague and depends heavily on the terrain and the road you are driving on. Obviously, an uphill section is going to put more heat into the transmission than a downhill section where you are beating up your brakes more. Also, a relatively flat section that is full of tight hairpins where you aren't really going that fast and have very short sections where you are on the throttle isn't going to beat things up too badly even though you are having a great time.

Ambient temperatures also play a factor in the transmission temps. Down in the valley, temps were up at 106 degrees and up in the mountain, temps were 78 degrees. Remember, the transmission is an aluminum case and aluminum is great at conducting heat. The steel plates, drums, shafts and whatnot do store a bit more heat so it takes them a little longer to dump any heat they absorb.

The conclusion of this testing shows that even at stock power, an ft86 driven on the track really ought to have a transmission cooler. If you just use your car as a daily driver, never do track days or spirited driving, don't worry about it. If you do spirited driving, I highly recommend a transmission fluid temperature gauge, preferably one with a warning feature you can set for 250 degrees Fahrenheit (120 degrees Celsius). If you find that you are consistently hitting that warning on canyon runs or whatever, it's time to invest in a transmission cooler. Ultimately, this is a lot cheaper than replacing/rebuilding the transmission.

One last thing I'm going to do before installing the transmission cooler is get a UOA on the transmission fluid. I only have 11k on the clock, but with a track day and a few hard runs, I want to know how it is holding up.

Stay tuned for more updates: next up testing with a transmission cooler installed.

[Captain Insano]

Great info!! Thanks for posting.


Wondering how the fluid analysis will turn out and especially if there is better fluid options for both daily driven car vs track driven car.

[s2d4]

Question if I may, how are you guys planning on activating the system? Running all the time? Manual switch activation and when? Temp activation at what temp? Separate for pump and fan or at the same time?

[stonenewt]

I was thinking about a Laminova water/oil heat exchanger. This shouldn't need any control as the fluid will be held to around +10C over coolant temps, which should will be about 100-105C.

[MmmHamSandwich]

Originally Posted by Sithspawn

Update:

Thanks for taking the time to do all this testing and providing the results for us. Looks like if I decide this car has much of a future with me I'll need to invest in a cooling solution.

Does make me a bit worried, I've done a few mountain runs myself, even during break in. Lots of long uphill pulls. Still shouldn't approach the abuse experienced at a road course though, so it's probably fine. Still, especially if I end up FI'ed, I'd like to take preventative measures to keep my transmission healthy.

Mine car is coming up on 20k miles soon. My dealer has farked me over soo many times I asked nicely if they would consider changing the ATF for me since it is a pain and I would really appreciate it after all the crap I've had to put up with from them. Nope, they have a laundry list of excuses for that one.

[nlowell]

Any updates?

[Sithspawn]

Originally Posted by nlowell

Any updates?

I got the transmission cooler hooked up, but didn't get much opportunity to put it through its paces yet. So far, steady state driving shows the temps are quite a bit lower than stock (I didn't have my laptop with me so I didn't get exact temps). I did a mountain run and noticed that the temps never got above ~200 - 205 degrees Fahrenheit even with hard driving. The Innovate gauges display temps with LED's instead of a needle or digital readout, so without the laptop hooked up, I didn't get precise readings.

Overall, the cooler definitely keeps the temps low. I'm going to run the car on the track again this coming Tuesday night with the laptop hooked up and will be able to report back more data then.

I also just received my Blackstone Labs sample kit today, so I'll be sending off the used transmission fluid for analysis on Monday. I will say that after topping off the transmission with fresh fluid and additional fluid to make up for the cooler circuit, the transmission shifts much smoother on the 1-2 shift in manual mode.

[snidd111]

Huge thanks for all of these posts. I'm looking at going FI, but definitely have cooling solutions on my to-do list before the SC.