Oil Cooler Duct Final Testing and Conclusion
We finally made it back to VIR this past weekend where we were able to get some more conclusive results from Alex’s 2018 Golf R which we did initial testing and then even more testing/prototyping on earlier this year.
We found out that his oil cooler was slowing the car down something badly since the hot air was heating up the “cold” side of the intercooler (and radiator), showing up as wildly high IATs (50F+ over ambient) even with an APR intercooler. While coolant temps were not a problem, they weren’t great/any better than stock which was especially disappointing since he has all 3 CSF radiators (main/aux oil/aux DSG).
We DID do track testing already, but the before data was from our home track at VIR, and his after testing was done at Palmer Motorsports Park. We wanted to follow up with one last in-depth analysis at temps back at VIR.
In a nut shell, by just moving the oil cooler to the center and adding a simple sheet metal duct he was able to gain 8-9mph on the back straight at VIR, with no other changes. He was not running a lap timer, but this should equate to easily 2-3 seconds per lap between the front, back, and bridge straights at VIR.
The initial street testing, various configurations, testing at Palmer, etc were covered in the prior post. These final results from VIR were appended to the full summary/report so you can reference the testing from beginning to end.
Oil temps are not included as part of the report as last year when we discovered the issue, we were not logging the direct oil temp (Oil Temp MDI, same as what is in the dash)… just the modeled temperature which is wildly inaccurate once more power and a bigger radiator/oil cooler are added. Oil temps were never a problem with the oil cooler installed, this study was to determine the ill effects of the hot air coming off of the oil cooler causing other problems. You can see the FULL session reports (with oil temperatures) here, labeled as user “redslaya”:
>>> The FULL reports (including oil temps) with detailed notes can be viewed here (user “redslaya)
>>> The Oil Cooler Effects on ECT/IAT Summary/Report can be viewed here
Add this duct to fix YOUR problems!
Alex was kind enough to release the CAD files for free. It is licensed for your use under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International Public License.
Basically, you can use it, modify it, build off of it, but you can’t commercialize it and your derivative work must be licensed under this license as well. This was made and publicized to help the community, not make a buck.
CAD files 1+2+3 are the individual parts that must all be cut and assembled together. This was designed specifically for the Setrab 19-row Series-6 oil cooler. You are free to modify the CAD files to fit whatever oil cooler you want, but if it is not Setrab part number 50-619-7612, then it will not directly fit.
Link to the Notes, CAD files, and License Information HERE
This CAD file can be sent to www.sendcutsend.com to be produced just like he had done.
0.063" 5052 Aluminum is recommended as the material to be made out of. For reference: it cost about $95 cut, bent, deburred, and shipped (as of 08/23/23). You will need a BUNCH of 3/32 x 1/4in pop rivets to assemble. Just get a 100ct package. Be sure to read the notes document in the above Google Drive folder, and know that it will involve cutting a rectangular hole in your lower bumper cover for the air to escape.
