Automatic Transmission Fluid Cooler. ??
 

Hello,

In a few month I am planning on doing a turbo kit with around ~300 rwhp as a daily driver build set up. I already have an oil cooler kit, upgraded radiator, and an engine thermostat, lastly I want to have an Automatic Transmission Fluid Cooler, just to ensure everything is being properly cooled as I will be daily driving the car.

I know that SSP has one, but is waaay over priced.

What are other options? Prices? Anybody else running an A/T fluid cooler?


Thank you

I used a B&M cooler kit, had to get some extra hose and an adapter fitting. Also Depending on your millage you may want to go ahead a do a trans flush. You would be surprised how poorly the fluid looked on the one we installed with 27k on it. This is the cooler I used. http://www.bmracing.com/products/702...-rating-black/

So far seems to be working well, I will report back after tuning as the car is currently only on spring pressure.

Awesome thanks for the reply! My car has 18k miles on it

Some questions for those who installed coolers...

1.) Did you install a pump as well? I noticed all of the "complete" transmission cooler kits for our car (Cusco and SSP) include a pump. Is this to ensure proper flow/pressure through the radiator system?

2.) Where did you mount the radiator? I have too many coolers up front already so my two options are a small fan cooler in the passenger fog light area (SSP style) or one tucked back by the muffler cavity (Cusco style).

3.) What path did you take to run the oil lines? Any pictures?

I like the fog area design but the smaller radiator with a temperature controlled fan is $200 versus the ~$70 larger/no-fan design from B&M. I think the rear location is also less travel distance for the oil to the radiator.

I'm going to be doing some R&D on this one. I just picked up a pair of Innovate MTX Oil Temp/Pressure gauges to do some logging before and after installation of a trans cooler. This way, I can determine if we can get away without running an auxiliary pump (thus the pressure sensors) and seeing how effective/ineffective the factory cooler is under various driving conditions to establish a solid baseline. I'll also publish the results of my testing in nice little write up for everyone.

Looking forward to this!

Ditto, curious about this topic as well.

Where are you guys installing the cooler and running the lines?

I received my B&M 70255 and it looks like it will fit in the passenger fog light spot. It'll be tricky to mount securely and even more tricky to run the lines. Looks like the best way is to run the lines across the crash beam to the driver side fog area then down the frame rail to the stock cooler. Looks like that will require ~9 feet of hose each way. I'm somewhat concerned about running 18 ft. of hose plus the radiator. Any thoughts here on if the distance will be ok with the stock transmission oil pressure?

Pressure is indeed a concern that I have. That is why I am going to be hooking up pressure sensors to the transmission cooler lines. Now, I have read that the B&M has more pressure drop and is substantially less effective than a similar size Setrab core, but I am curious. Since the B&M is so stupendously cheap, I might just pick one up to do a comparison between a B&M core and a Setrab core since I have the data logging capability to do a proper comparison.

Give me about a week or two to get a baseline on stock temps and pressures.

:popcorn:Subbed!

Update: I got the Innovate gauges installed and got everything to steady state at idle last night. Here's what I've discovered so far. The factory lines running to and from the factory cooler are low pressure lines. Cold start showed 12psi from the transmission to the cooler and 9 - 10psi from the cooler back to the transmission. This is good news since it doesn't look like you have to go crazy with high pressure lines and fittings: push lock hose and band clamps appear to be sufficient.

Steady state at idle showed the temperature coming out of the transmission to the factory cooler is 189 degrees and the temperature going from the cooler to the transmission is 192 degrees with coolant temperatures at 199 degrees. At these temperatures, the pressures were at 9psi out of the transmission and 8psi going back to the transmission.

Traditional ATF has been mineral based and these temperatures would be considered rather high as a mineral based ATF starts breaking down above 180 degrees. The Toyota WS fluid used in our transmissions is a synthetic fluid and can take a lot more heat before breaking down. Also, the WS fluid is relatively thin compared to other synthetics and has great thermal stability. Toyota uses this fluid in a number of other vehicles as well to help improve fuel economy.

While the fluid can take a good bit of heat, there are other components in the automatic that can't: seals and clutches. Generally, seals start to harden up around 260 degrees Fahrenheit and clutches will start to slip and degrade quickly at temperatures above 290 degrees. Therefore, we don't really want to be seeing temperatures above 240 - 250 degrees to ensure longevity of the transmission.

One other note is that while installing the gauge sensors, I captured some of the ATF that came out of the factory lines. With only 11k on the odometer, the fluid is starting to darken and there is a little bit of particulates in suspension. The fluid does not smell burnt, but it is getting a little wear. I have done a little spirited driving and I have noticed that the 1 -2 shift with the paddles is rougher than when the car was new.

I'm going to be doing some data logging today with a mix of normal (for me) street driving, highway cruising, spirited driving up and down a mountain pass as well as some light track driving at Adams Motorsport Park in Riverside, CA. Adams is a short technical track that comprises 3 laps per run with about 3 runs in a 1 hour session. The laps are 53 - 57 seconds long and back when I had my manual FR-S, I would top out 3rd gear on the main straight.

Stay tuned for more information as I acquire it.

Love the data!! I noticed the same with the fluid I caught. I think it's time for a flush soon but I'm not sure if I stick with WS or something more track friendly. I've heard WS is some pretty good stuff.

Good news on the temp - I was worried about the 200 degree temps I am logging between the stock and aftermarket cooler under spirited driving. Looks like that might be ok after all.

Pressure is good news as I always fear of blowing the lines but that is also steady state right? I was under the impression that pressure rose linearly with the engine speed in the mechanical transmission pump. Is this the case? If so then the max is what matters, right?

Thanks again for spending this time. Your output will be very valuable to all AT owners!

Subbing :)

Update: I did not get a chance to do the mountain run, but I did take the car to the track as well as some street driving and highway cruise. Also, the highest pressures logged were 13psi. It seems the valve body regulates the line pressure to the cooler circuit and the pressure is typically 8 - 10psi.

Highway cruising at steady state came back with 194 degrees going out of the transmission and back in. Generally, it was very stable and only occasionally varying by a couple degrees.

City driving, however, had a lot more variation in temperatures (as to be expected), but they had a tendency to run a bit higher at 205 degrees coming out of the transmission and 201 degrees returning from the factory cooler. Here you can see the factory cooler actually bringing temps down compared to steady state at idle where the "cooler" was actually keeping the temperature elevated.

For the most part, the factory transmission cooler works great and does exactly what it needs to do when driving Miss Daisy, getting groceries and normal day to day driving.

When you take the FT86 to the track, however, we found that the factory transmission cooler just cannot keep up. At Adams Motorsport Park we ran the 3rd session of the night and it was 80 degrees Fahrenheit ambient temperature. A session consists of 3 runs (3 laps each) with approximately 10 minutes between each run. Each lap took between 51 and 55 seconds.

During the first session, the transmission outlet temperature started at 205 degrees and climbed up to 216 degrees. The return temperature from the factory cooler started out at 199 degrees and climbed up to 214 degrees. OK, no big deal the temperature isn't out of control and there is a 10 minute cool down before the next run.

The second session, however, showed that in 10 minutes, the transmission hadn't dumped the heat accumulated from the previous session and was still fairly warm with temperatures starting out at 214 degrees from the transmission and 212 degrees on the return. By the end of the session, temps had climbed to 228 degrees coming out of the transmission and 223 on the return. Notice that the cooler is only pulling 5 degrees of temperature from the fluid at this point.

Now for the 3rd session, the transmission has really started retaining heat as the outlet temperature remained at 228 degrees and the cooler is not doing so well now that the car is heat soaked with temperatures coming out of the cooler at 225 (only a 3 degree delta). By the end of the run, the temperature had climbed up to 244 degrees coming out of the transmission and 235 degrees going back to the transmission. My gauges were in the red by the end of the last lap and my co-driver called out over 240 as we were pulling into the pits.

Keep in mind that this is just a total of 8 minutes of track time with two 10 minute breaks on a stock car with stock power levels. Most HPDE's at a full size road course are 20 minute sessions. While I would be interested in seeing how high the temps go during a 20 minute session, I'm not really inclined to subject my transmission to that kind of abuse without proper thermal management.

The bottom line here is that if you track your FT86 and you have an automatic, you need a transmission cooler to keep the temps in check.

I'm still going to do a mountain run and log the temps to see how much sustained driving it takes to get the temps to 240 degrees. After that, it'll be time to hook up the cooler and see how it does.

Stay tuned for more.

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.

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

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

Attachment 90467

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.

Thanks!

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.

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.

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?

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.

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.

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.

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.

What cooler did you end up going with?

I'm going to guess the setrab

@Sithspawn
I have one of the p3cars gauges that lets me hook up a couple aux sensors. How'd you setup your tranny temp sensor? And did you just use the Innovate water temp gauge?

We went with a Setrab Series 6 19row oil cooler.

For R&D purposes, we put one pair of sensors (temp and pressure) in the transmission line going to the factory cooler and one pair of sensors in the line returning to the transmission. This way, we could measure the delta across the factory core in the before testing. With the auxiliary cooler added in the circuit, we could measure the total delta across both cores.

UPDATE: For starters, we plumbed our auxiliary cooler before the factory cooler. The idea is to allow the factory heat exchanger to warm up the fluid to operating temperature quickly. If we have the auxiliary cooler after the factory heat exchanger, then any heat added by it would promptly be removed by the auxiliary cooler.

At the track, temperatures are lower than stock, but still not quite ideal. We did hit 233 degrees Fahrenheit at the end of the third session. While that is 11 degrees cooler than the stock cooler and not quite in the danger zone, it is a little higher than we would like to see. I would prefer temps to be in the 220 range at the end of the third session.

Next we did some airflow modifications to get air moving through the core more effectively. We added a series of louvered vents to the back side of the fender liner and cut out the "T" pattern in the factory bezel on the lower passenger side of the FR-S. A quick test on the mountain showed a noticeable improvement as temps peaked out at 203 degrees coming out of the transmission and 189 degrees after both coolers. This was after a 21 minute run to the top of the mountain.

Now, while I would like for the temps to come up quickly (especially in winter), the current configuration shows that the factory heat exchanger is adding heat when we want it to be cooling. The only way to have our cake and eat it too is to add an inline thermostat to the system and plumb the system so that it goes: transmission -> factory heat exchanger -> thermostat -> air/oil cooler -> transmission. When the fluid is below operating temperature, the air/oil cooler will be bypassed so that temps can come up as quickly as possible. Then, when you are on the track and pushing the car, the thermostat will open for maximum cooling and the fluid going back to the transmission will be as cool as possible.

Hopefully I'll have a thermostat in hand before next Tuesday so I can get it installed in time for track testing.

This all said, for a mostly street driven car with occasional canyon runs, the airflow modifications are not necessary and the cooler size/configuration we selected will be perfectly fine.

For automatics that see track use, the additional airflow modifications and thermostat would be a very good idea, but it is best to monitor your transmission fluid temps to see if they are necessary for the track(s) you frequent. If the car is strictly a track car, then a thermostat is not necessary and the air/oil cooler should be plumbed after the factory heat exchanger.

As you can see, what your car needs depends heavily on how it is used. Be sure to take a moment and reflect on how it is driven and decide on your configuration accordingly.

Stay tuned for more testing.

I would love to see pics of the air flow modifications if you have any.

Me too! I have the cooler in place and see good results but it's supposed to be 100 degrees at Buttonwillow next Saturday so I want to give the transmission as much help as possible.

What size fittings did you guys use for the cooler? What kind of hoses did you use? @Sithspawn and @nlowell, you guys could be AT heroes if you could post pictures of your setups!

I've read that just the generic 3/4" fittings that come with the universal kits work fine

Automatic Transmission Fluid Cooler. ??
 

Sithspawn will do a much more thorough job but I used a small 3/4" thick plate and fin B&M cooler (I'll post the model number when I'm not at seaworld). I purchased 20 feet of Edelbrock -6AN stainless steel braided hose. I went with braided to eliminate kinking since it was going to be run through some decent bends. I went to the hose store and pieces together a 1/2 inch to 3/8 reducer that also had a 1/4 inch hole for my temp gauge sensor. I also purchased a straight 1/2" to 3/8" barb reducer for the connection back.

I cut the hose exiting the stock transmission cooler, inserted my custom reducer, ran the braided hose down the drivers side, across the crash beam, to the passenger fog area where the cooler is, then back the same way and back into the transmission using the 3/8 to 1/2 barbed adapter and the existing stock hose still connected to the transmission inlet. I put hose clams on every connection and used tons of zip ties to make sure nothing was going to move or get in the way of anything else. I then cut the braided hose on the return line on the crash beam and inserted a filter. Wired up the temp gauge, added 1/2 quart of WS fluid into the transmission using a fluid pump and done. The gauge isn't the best placement since it's already after the stock cooler but I was lazy to splice it before the cooler. Word of warning, wear gloves with the stainless hose - the ends can hurt :)

Attachment 92097

Attachment 92098

@nlowell that setup is awesome. Do you have after market fog light housings? Mine don't allow air through them

@nlowell, thank you! Awesome setup!

Thanks guys! I don't have fog lights so I just cut holes in my fog light covers. Most can put the cooler in front of the radiator but I already have an intercooler, oil cooler, SC oil cooler, radiator, and condenser all fighting for air up there.