Now we can assure you that your track days will be much cooler with Alekshop new oil cooler for E9X M3.
After spending a lot of time at the track and seeing really high oil temps on our E92 M3, we thought it’s a MUST to upgrade the oil cooler as the stock one seemed really inefficient.
Below are the graphs from our testing. You can also find more info on BMW forum
So we started looking into getting what was already on the market just to improve the oil cooling and reduce operating oil temperatures. A customer of ours had an oil cooler made by a company in Germany (Company A) and after seeing his temps at the track we didn’t see any improvement over the stock cooler.
The next on the list was an oil cooler made by a big California company (Company B). After talking to (Company B) it seemed like they have a good product and we were assured it will reduced oil temps by ~ 20%. We ordered one, got it installed and decided to put it to test right away. During the second session at Laguna Seca race track, the car went into reduced power mode and warning was for high oil temps (nearly 300F) and the car needed to cool down before we can drive it again. By then the oil was cooked and we couldn’t run anymore. So a few weeks later we decided to give it another try and hook up Solo DL for data logging to see the actual oil temps and not rely on the stock gauge which is hard to read anyways. Unfortunately we didn’t see any improvement as well and oil temps were in 271F range which forced us to do cool down laps during the sessions. Not fun.
So that left us with one option – to build a cooler that will meet our specs and make a difference in oil cooling.
After taking a close look at (Company A) and (Company B) oil coolers, they had one thing in common, tall fins and the same number of oil line rows (Company A actually has one less) as the stock cooler. So we concluded this was the answer why we didn’t see any improvement with these coolers over the stock one.
We decided to use a completely different core with a staggered fin design. By using this core we doubled the number of fins per row while maintaining the same distance between the fins for a perfect air flow.
Why did we want to maximize the number of the fins per oil line row? It’s simple, the more fins you have the faster they can dissipate the heat from the oil lines.
Next we decided to add more oil line rows for better cooling. So we added 6 more oil line rows which came out to be 14 in total (stock is 8). We were concerned that such a tall core might impact water temps due to the heat transfer from the 6 extra oil line rows.
We also wanted to make sure our new cooler will accept factory oil lines and will bolt in the same place without making a lot of modifications to the car. After multiple test fitments, we were able to make it fit perfectly and only a bit of plastic had to be trimmed to accommodate our new cooler.
Now, the best way to find out if it works was to put it to the same test and take it to the race track and start data logging it.
The results were pretty surprising. We honestly didn’t think it will make a huge difference, but we were wrong. The highest temperature that we logged that day was 239F with no negative impact on water temps. Not only that, our cooler reduced the operating oil temperature by 13% (32F), but it also maintained the same temperature during the entire section without much fluctuation. You can see in the graphs below how consistent water and oil temperatures are compared to other coolers that we used.
- Staggered fins design
– 14 Oil line rows (stock only 8)
– Approximately 80% larger core than stock
– All aluminum construction
– Engineered for maximum performance and heat transfer
– Oil capacity increased by approximately 2qt
– Track tested and proven 13% (32F degrees) oil temps decrease
– 100% test rate – every single oil cooler is pressure tested
– Lifetime warranty
– Made in USA