Turbo charged cars tend to be hard on engines, as along with increasing power, turbos also increase temperatures dramatically. And these high temperatures are the enemy of reliable operation. So keeping cool is of utmost importance, especially for when an old, force-induction, little 3-cylinder engine is running hard on mountain roads, on the track, or even just cruising on the highways at speed.
Oil coolers are essentially small radiators connected to the oil system and are designed to cool the engine oil that passes through the cylinders and turbo. The radiator on most cars only cool the fluid passing through the engine block, so many cars don’t have built-in provisions to cool the oil. In an aftermarket application, the oil cooler is attached to the engine by the means of a sandwich plate or remote line connected to the stock oil filter location. The necessary oil filter, of course, is retained.
While oil coolers are not specifically only for turbo cars, arguably they are more needed here than for a naturally-aspirated engine. The oil, also passing through the turbo, is at a dramatically higher temperature during even normal operation. So reducing heat during high RPM and boost is critical.
There is an additional benefit to installing an oil cooler. The sandwich or remote relocation plate is also often tapped for use of two or more aftermarket sensors, which will allow an oil pressure and/or oil temperature gauge to be installed easily, as hopefully you’ll see later.
At a mere 11,000￥ ($100 USD) for this complete package with oil filter relocation plate and three hoses. This “universal” oil cooler package was very, very cheap. The 13-row oil cooler radiator itself is 29 x 9.5 x 5 cm (11.4” x 3.7” x 2”). The long AN10 braided hoses and adapter seem to be of a decent quality, nicely anodized, and cleanly machined. But let’s keep expectations low here as we start this multi-post series on my Suzuki Alto Works.
One thing I needed to pick up is an oil cooler with an oil filter relocation instead of just a sandwich plate. The oil filter from the factory is at an extremely inconvenient location, nestled deep between the alternator, A/C radiator, and exhaust manifold, our hands and tools are barely able to reach it. Honestly, my mechanic and I agree it’s a terrible location.
With an oil filter relocation plate, I can move the actual filter off-engine to somewhere far more easily accessible. This modification will also make things much, much easier for me in the future to just change the oil.
Looking at the front panel of the car, there sadly really isn’t any place for this to the right of the radiator, as the AC radiator is quite large and takes up more than half of the front grille, unlike many other kei cars where the AC is half the size. Great for summer, I guess? This leads me to the only two other possible choices, the “yankee” option or a stealth option.
I call this the “yankee” option. For those of you that aren’t aware, the term yanki in Japan is often applied to delinquent youth or, in the bike and car world, illegal or obnoxious vehicle modifications. Such is the case with mounting an oil cooler externally, which is most definitely not a legal location for street use cars. This is not only potentially dangerous for pedestrians, depending on where I plan to mount it, it will partially cover one or more lights or require relocation of the license plate.
On the other hand, mounting externally will definitely provide the maximum amount of cooling, as the whole radiator will have direct airflow, not to mention it will look awesome with it hanging off the front bumper.
Inspired by various kits and DIY photos online, the stealth method involves me hiding the oil cooler radiator behind the front bumper bodywork. There is little space unoccupied on the front bumper of the Alto, so unless I plan on blocking airflow directly in front of the AC or engine radiators, I will have to remove the right fog lamp and place it behind there. As the fog lamp itself is quite large at 12.5cm (4.92 in) diameter, it should offer more than adequate cooling for the diminutive dimensions of the oil cooler. The drawbacks of this location will be the fact that I have to cut the metal fender lining to pass through air and that I will lose the use of one fog lamp. In fact, when it comes to the time I need to do the biannual shaken (mandatory maintenance), I must remove the left fog lamp as well (or remove the oil cooler). However, it is definitely the stealthiest option and would draw the least amount of attention, negative or positive.
What would you do?