(This is pretty long so skip to the bottom for picts and cliff notes)
For several years I have been experiencing pretty excessive oil temps at the track (road course) so I decided to start looking for an oil cooler for my 2005 STI. I really wanted to mount the cooler in the hood scoop but I didn't want to go trough the trouble of fabbing up a custom bracket system. Fortunately I discovered the B-Line Motorsports top mount oil cooler kit and decided to order one. The standard kit includes a 25 row Setrab oil cooler, a set of extremely high quality fire resistant -8 AN lines that come pre-assembled with all the AN fittings, silver fire shield for the 3ft of the lines that are near the exhaust, a standard sandwich adapter (not a thermostatic adapter) and the custom mounting brackets for top mount fitment.
The kit retails for $565 but I was able to get it through a vendor here on Nasioc for $500 shipped plus and extra $25 for the upgrade to a thermostatic sandwich adapter. The only part of the kit that is 100% exclusive to B-Line are the custom mounting brackets. If you wanted to fab up the brackets your self you could easily save a few bucks by getting all the items from racerpartswholesale.com.
The kit came with easy to follow picture base instructions however, the kit was so simple to install that I did little more than skim through them before I started wrenching. Even though it was not in the instructions I attempted to prime the oil system before starting the car the first time just like you would for a new turbo or something. I unplugged the fuel pump relay harness (under the glove box) and cranked the motor for 30 seconds and waited two minutes before cranking it again. It was my intent to to do this for five cycles but during the third cranking cycle I discovered that something was very wrong with the B-Line supplied thermostatic sandwich adapter! I started to hear a sound similar to the noise that comes out of a squeeze bottle of mustard when its nearly empty (splattering and spitting with air mixed in). I got out of the car and looked under engine only to see lots of super expensive Motul oil shooting EVERYWHERE! After some investigation I discovered that the B-Line supplied thermostatic sandwich adapter had a design defect causing it to leak oil between the adapter and the oil filter. I immediately called B-Line and told them what was going on. The guy who answered the phone was very apologetic and promised to get to the bottom of the situation very quickly. We talked through the situation and concluded that the thermostat adapter would need replaced. Since they only had defective thermostat adapters in stock he opted to temporarily overnight me the standard non-thermostat adapter at their cost which I could then use until they figured out what to do.
I got the new adapter the very next day and repeated the install just the same as before. I was very glad I decided to prime the oil system because I didn't see any oil pressure at all until nearly the end of the THIRD cycle (~85 seconds of cranking). During the entire 4th and 5th cycles of cranking I saw about 65psi of pressure so I figured that it was safe to start the car. The initial startup was uneventful but I did notice that my oil pressure was down about 15psi from where it had previously been. FYI, I monitor the oil pressure using a defi oil pressure sensor in the rear oil gallery plug.
After the car came up to temp and I was 100% sure that there were no leaks I when out for a drive. The oil pressure was about normal for idle and light cruse so I decided to do a few pulls. After seeing that my oil pressure was down nearly 20PSI from normal at redline I became pretty concerned and headed home. I also noticed that my oil temps were starting to get very low (under 165F) which also concerned me. I kind of expected the low temps but the low pressure at redline was a real shocker. After researching my situation for a few nights I called B-Line back and explained the situation to the same guy as before. He was again very apologetic and told me that he would need to consult some of the other guys that he works with for advice. While I waited for a call back from B-Line I decided to give BAT Inc. a call to see what they had to say about the situation. Knowing that BAT had years and years of motorsports experience with oil coolers I figured that they would be able to help.
The sales guy from BAT was extremely helpful and made a number of suggestions starting with an upgrade to -10 AN lines. He also told me that the sandwich adapter that I was using (non-thermostatic) was of very low quality (it looked pretty ghetto) and was likely a large portion of my problem. He also suggested that I remove the factory oil/coolant heat exchanger since it would help cancel out some of the pressure drop experienced when installing an aftermarket oil cooler. Since I didn't have very much confidence in the sandwich adapters that B-Line was selling I opted to purchase a 200F MOCAL adapter from BAT. I went with the higher temp adapter because the BAT sales rep told me that the Setrab cooler would be "extremely efficient" when placed in the hood scoop and that a 180F adapter would most likely continue to allow the oil to go below optimal operating temp. MOCAL adapters use special dowty seal based fittings so I had them include a set that terminated in -10 AN (these are the black fittings directly on the adapter).
Once I got off the phone with BAT I decided to call B-Line up again to work out some kind of deal to get my project moving forward again. After all the trouble I had they were pretty eager to work something out which made me very happy. I was able to return both the sandwich adapters I got from B-Line, all the -8 AN fittings, hose etc so I ended up keeping ONLY the Setrab cooler and the custom brackets. In return, they "upgraded" me to all -10 AN hoses, fittings for a marginal fee equal to the sale price difference less the cost of the thermostatic sandwich adapter that I originally purchased. Even though the experience was far from perfect, I am impressed with the customer service at B-Line.
After receiving everything, I removed the factory heat exchanger and did a more or less custom install (didn't follow the B-Line instructions at all) using the new -10 AN hardware and the MOCAL adapter. The picts and the video do a pretty good job of showing what I ended up with and how I ran the lines.
Here is a bit of oil pressure and temp data from some testing I did today:
-100% cold start (not run in 24 hours): 98PSI / Ambient Temp
-Full temp idle (after driving for 10 miles and sitting for 1min): 40PSI / 194F (No change from pre-oil cooler temps)
-Full temp cruse at 65mph: 84PSI / 180F (10F drop in temp)
-Full temp at stock 7200 RPM redline (after several pulls on the highway): 90PSI / 190F (20F drop in temp)
-After 20min of hot laps on a road course track: SOON!
I am extremely pleased with the results. I basically have zero pressure drop from stock and oil temps
The standard B-Line top mount kit has insufficiently sized hoses and a low quality sandwich adapter that causes low oil temps and excessive oil pressure drop. Upgrading to the -10 AN line option and using a high quality MOCAL sandwich adapter (sourced elsewhere) makes the kit just about perfect. The center coupler needed to attach an aftermarket oil sandwich adapter directly to the block is Subaru part number 15018AA050.
The customer service at B-Line is excellent.
BAT Inc. is a great source for a proper sandwich adapter.
Video tour of the finished product: http://www.intertrick.org/nasioc/ima...Oil_Cooler.mp4