Competition Series Dual Oil Cooler Upgrade Kit for the 2006-2013 135i/335i N54/N55 Engine

Those of you who track your cars know what we're talking about.  Many nightmares and sleepless nights.  Plenty of days, waking up before the sun comes out, loading up your gear and heading to the racetrack (sometimes hours away) to go race only to be ruined by the dreaded limp mode on the very first hot lap.  Hundred of dollars wasted on a track day you can't enjoy because your car can't make a single lap under full power.  The disappointment.  We felt it.  We know how you feel.  This was our life the very first year (2008) we started racing our 135i.  Every single race, we fought it.  The dreaded limp mode.  Our driver would shift at 4,500 rpm and every other lap would be a cool down lap.  Life was miserable.  For those who don't know, limp mode is when your ECU detects something is wrong and cuts almost all power to the car in hopes of saving itself.  What was causing it?  Oil temperatures.  We were easily seeing over 260F even on a cold day.  By 265-270, limp mode would hit and that was the end of it.  We did additional testing on a dyno by doing constant runs and datalogging what was going on which confirmed that oil temperatures were the culprit.  Interesting thing was that when the car hit limp mode, power would drop to only 50whp every single time.

Once, we figured out it was oil temperatures causing the limp mode, we went straight to work trying to solve the issue.  We started off first by adding a small auxilary oil cooler in conjunction with the factory oil cooler.  This was a laughable attempt.  This did absolutely nothing noticeable.  The next race, limp mode just like before.  Our next attempt, we thought maybe the factory oil cooler just wasn't really efficient.  Thus, we changed that out to a new, larger unit.  With the new oil cooler with the small auxilary oil cooler, we finally saw a slight drop in oil temperatures.  However, it wasn't much and again, at the next race, limp mode.  Our next attempt saw us building ducting shrouds to channel cold air to the oil coolers.  Again, this saw another drop in oil temperatures and better ability to fight off "heatsoak" but still, not enough.  The car would still limp at the track.  Fustration was setting in for us.  Many long days going to the track being ruined by limp mode.  This was our 2008 race season.

With the 2009 race season looming, we decided to go all out.  We were tired of limp mode.  Tired of trying to get the car to do 1 lap under full power.  Tired of finishing in the middle of the pack.  This was when the twin oil coolers was born.  We scrapped the small auxilary oil cooler and added an identical oil cooler on the driver's side.  Thus, we had 2 large oil coolers, one on each corner.  The first race, everyone though we were crazy running 2 large oil coolers., yet SUCCESS!  Oil temperatures had dropped significantly.  We were now able to do more than 1 lap under full power. 

Yet, this was not the end of the limp mode journey.  We're located in Southern California and thus, we frequently see ambient temperatures over 100F.  Our race tracks are also all located in the high desert region.  Perfect for some extreme testing.  Even though the limp mode issue was now under control with the twin oil coolers, on very hot days, it would rear its ugly head.  Also, on certain high speed tracks where we would be at WOT for long periods of time, like Autoclub Speedway's oval configuration (think Nascar), we would occassionally hit limp mode.  Thus, we spent the entire 2009 season refining the twin oil cooler system.  Originally, we had routed the oil lines so that the oil split at the oil filter housing.  This originally started because of our earlier attempts to keep the factory oil cooler.  Yet it dawned on us that this was not efficient.  In essense, since the oil was being split in half, each going to one of the oil coolers, we weren't cooling all the oil with both coolers.  Granted, it still worked since each cooler is now only charged to cool down half the oil in the system but it was inefficient.  Thus, we devised a new system to run the oil lines sequentially to take full advantage of both oil coolers.  Oil now runs from the oil filter housing to the first oil cooler.  Then it runs to the second oil cooler and back to the oil filter housing. Basically, now 100% of the oil was going through both oil coolers.  With the new oil line system, we saw a big change come race day.  The oil temperatures again dropped but what also changed was how much longer the oil cooler fought off "heatsoak".  Temperatures were more stable and stayed lower longer throughout the whole race session. And the best thing of it all?  We completely SOLVED the dreaded limp mode problem!  By the end of the 2009 race season, limp mode was a thing of the past.  Regardless of temperature or track, we NEVER again experienced the dreaded limp mode!

2010 race season was monumental for us.  With all the refinements made in 2009 to the twin coolers and solving the limp mode issue, we were FINALLY able to really work on making our 135i fast.  Instead of spending time and energy trying to fight off limp mode, we spent it making tweaks and upgrades to our 135i.  The first race of 2010 saw us podium in 2nd place.  That was the beginning.  Every single race after that saw us take podium finishes.  July 4th, 2010 saw our first victory with a first place finish in Street RWD as well as Street Overall Class and setting a new class track record at Willow Springs Raceway.  Every since then, we have claim a 1st place Street Overall victory at every single event and even recently set another class track record.  All this happened because of oil coolers... the Competition Series Twin Oil Coolers that solved the dreaded limp mode.