DCT fluid flow diagram - Aux DCT Cooler install

[bbnks2]

Originally Posted by AndyW

So, based on houtan highly technical and not cartoonish in any way drawing, I made a thing (to quote Jeremy Clarkson)...

So, I realized I needed additional cooling for my track car. Oil was under control with two 19 row Setrabs, and coolant had been mostly under control with a CSF radiator...until I added a Wagner EVO III Race FMIC (https://www.1addicts.com/forums/show....php?t=1810459) and a PS2 turbo. Then, on 85+F days, coolant would get into the 240's ("pre-limp" can start TQ Lim as low as 242F, apparently) and now DCT temp was getting into the 250's(Still don't know the setpoint for TQ limit for DCT temp, but I imagine it's somewhere above 245F, given when power cuts would occur). Since DCT temp was now my highest and I cleverly sussed out that BMW actually adds a decent DCT cooler to it's M cars, I went in that direction. I also knew that since there was a coolant to DCT cooler, anything I did to help DCT temps would also unload the radiator.

First problem is that our little car is cramped. There is little room to mount another cooler if your wheelwells are already full. Since my IAT's were now well under control and I saw some pics on the internet of race cars with DCT's that put their DCT cooler right in front of the radiator, I figured putting a cooler in front of the FMIC would be OK since it had the most "headroom" to spare now. I definitely didn't want to block the coolant radiator more than it already was as that would be counterproductive (although there is enough room to fit the cooler behind the kidneys).

Now to decide what kind. Since there is very little room now between my FMIC and the bumper cover, I had a conundrum. I could stay stockish and get a tiny thin cooler like this:



Or sacrifice the lower "grille" and get something meaty. You would be amazed at how much time I spent figuring out how thick various coolers were and what would fit in the less than 1" between the FMIC and the bumper cover.

In the end, I went with meaty and got a Setrab 13 row. I figured a 19 would block more of the FMIC than was desireable and the 13 seemed to be "right". In hindsight, given how little effect this addition had on IAT's, I could have gone with a 19".

I used some metal strap pieces I had in my parts bin and put M6 rivnuts in the underside of the bumper. Here is the assembly (before I cut out the extended holes to get the spacing where I wanted).



Here is what it looked like fitted up.





I used zip ties to provide some bracing to only having one bolt holding it to the bumper on each side. I didn't want it to "flop".

I reused my horn mounts from the PPK2 kit as zip tie supports...



Getting the Setrab meant I would sacrifice my lower grille, but that also took away the "baffle plates" on the ends of that piece to minimize air going around the FMIC. I solved that by cutting the center out of the grille with a dremel and keeping the side pieces (see final pic below). I did have to modify the bumper cover as the grille clips stick out too far.



Red indicates where i cut off the clips and in the center, cut forward about a quarter inch.

This was actually a "rev 1" pic. I ended up modifying more. Yellow indicates where i cut the clips in half (I was still trying to see if I could "save" the entire plastic grille).

For connecting into the DCT cooler loop, I decided -8AN was most appropriate and it was...-10AN would have been too big for routing the hose.

With some help from the pic above and Seems Legit garage I cut the *lower* trans cooler hose in the *crosscar* section. This is because that pair of hoses already hangs into the cooling fan space and I wanted the hoses to stay in the same direction only slightly offset.

I pushed these into the cut connections on the factory hose:



I built two hoses with the following ends to route to the cooler:





I actually built it with the straight connection for the cars lines and left the other end open so I could figure out routing to the cooler. Unfortunately, I didn't take any good pics of the routing, but basically you snake the hoses to the sides and up though the framing. I used the space behind my brake cooling intakes to have a nice large loop so there is excess for when you unbolt the cooler and pull it down for service or something (the connections are directly behind the bumper in this configuration when it is installed).

Once I had the length mostly figured out, I added some margin and cut. Overall, I used about 9 feet of -8AN twistlock hose. So about 4.5 feet each side.

On the cooler end of the hose I put the swivel joint. I wanted an angled swivel because it gave me more options and adjustability to control the hose routing behind the bumper and would be less stressful on the hose than going straight into the 90 degree fitting. Speaking of that, this is the fitting I used on the top of the Setrab.



I used zip ties to snug the all the hoses together under the car like this:



I was really concerned it would hit the fan, but amazingly, it does not.

Here is the final cooler hookup with connections. Swivel joints make this very easy to install and adjust once installed. I did have several iterations where the swivel joints had some minor weepage but altering and remaking the connections fixed it.



BTW, I did fill the cooler with FFL-4 right before hooking it up. And not much came out of the factory lines when I cut them. When I checked the DCT level I only needed to add about 400ml. I would estimate probably one full quart bottle for this job.

So, with everything installed, it looks like this (yes, that is me barefoot in my garage - don't judge ):



You can see here where I preserved the "wings" of the grille to prevent air bypassing the FMIC. My wife says it looks "almost stock", so I'll take it...

My latest logs speak for themselves on how well this works. Even adjusting for weather, it reduces trans AND coolant temps 10-15F *since any cooling to the DCT fluid means the coolant doesn't have to cool it). And it transfers a LOT of heat. Once session I came off the track, one side of the cooler was 176F and the other was 100F with an IR thermometer. And I estimate less than 5F effect on IAT's.

I am guessing you have not had any problems with those hose clamps, right? People have said the DCT pushes 200psi+ through the cooler but I doubt that and that must be the case since this setup would've exploded upon startup if it did push that much pressure. Those worm clamps aren't rated for even 100psi let alone 200psi and at 200f oil temps that rating is significantly lower.

Seems the working pressure through the cooler must be much lower. I ask because I am about to try to splice a cooler into my transmission lines.

[AndyW]

Originally Posted by bbnks2

I am guessing you have not had any problems with those hose clamps, right? People have said the DCT pushes 200psi+ through the cooler but I doubt that and that must be the case since this setup would've exploded upon startup if it did push that much pressure. Those worm clamps aren't rated for even 100psi let alone 200psi and at 200f oil temps that rating is significantly lower.

Seems the working pressure through the cooler must be much lower. I ask because I am about to try to splice a cooler into my transmission lines.

No issues. And no way it is 200psi...

[bbnks2]

Originally Posted by AndyW

No issues. And no way it is 200psi...

Yeah I can't imagine it is anywhere near that. I am sure hose clamps are fine. Thanks for confirming.

[houtan]

I’m working on a DCT cooler set up as well. Costing me an arm and a leg but it’s the route I wanted to go. Using the ER drivers side cooler with custom bracket so I can use the ppk2 radiator mounting solution. Went with improved racing braided lines, AN fittings, improved racing thermostat, and converted to MT coolant lines and radiator. About half way through the install. Need to design and print a bracket for the thermostat and router the lines. Also went with a bigger DCT pan from hpr. Will post back when I’m done as well.

[houtan]

finally finished my install. hoping to go for a drive in the next day or two but so far so good. no leaks.

I ended up making a bracket for the external thermostat that mounts in the same location as the DCT heat exchanger. I also installed the BW dry break fitting to get an extra quart in (GTS fill) after the ISTA fill procedure was completed. In total, I have about 9 quarts in the trans now.

For the oil cooler lines, I ended up using the factory hard line locations. For the location at the front of the oil pan, I made an L bracket to mount the oil line clamps to.

Also, if you go with the HPR TCA, you need a 45 angle AN fitting for the upper banjo, a straight fitting will not work as it hits a part of the transmission case.

All of the oil lines, fittings, and thermostat were from Improved Racing. I used an angle grinder with cut off wheel to make the lines, which was my first time doing, and it was straightforward.

Everything from HPR, Improved racing, bimmerworld, and ER from customer support to quality of products is top notch.

Additional pictures to show how I routed lines, thermostat bracket, etc.