Automatic Transmission Fluid Cooler. ??

[connor_lol]

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

[Ross]

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.

[connor_lol]

Originally Posted by Ross

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

[nlowell]

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.

[Sithspawn]

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.

[nlowell]

Looking forward to this!

[Captain Insano]

Ditto, curious about this topic as well.

[nlowell]

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?

[Sithspawn]

Originally Posted by nlowell

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.

[Tye300]

Subbed!

[Sithspawn]

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.

[nlowell]

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!

[86SPEED]

Subbing

[Sithspawn]

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.