Mishimoto E46 3-Series Aluminum Radiator R&D, Part 3: Prototype Evaluation

Mishimoto E46 3-Series Aluminum Radiator R&D, Part 3: Prototype Evaluation

Interested in purchasing our E46 aluminum radiator? Check out our product page linked below!

Mishimoto BMW E46 Non-M Performance Aluminum Radiator!

It's been a while since our last update. Don't worry, we have not abandoned our E46 aluminum radiator project. In fact, this may be the most exciting update yet. We are getting closer to bringing you guys a much-needed reliable and efficient radiator solution. Our line of BMW performance parts is growing!

Prototype Images

The wait is over! Check out a couple shots of our prototype radiator!

Mishimoto prototype E46 radiator
Mishimoto prototype E46 radiator

Mishimoto prototype E46 radiator
Mishimoto prototype E46 radiator

Mishimoto prototype BMW E46 radiator
Mishimoto prototype BMW E46 radiator

Here's a look at the engine-facing side of this radiator.

Mishimoto prototype BMW E46 radiator
Mishimoto prototype BMW E46 radiator

As you can see, we've included all the factory fan shroud mounting points and the inlet/outlet has been CNC-machined for a leak-free install with the stock quick-disconnect hoses.

Here is a close-up of the CNC component!

Mishimoto prototype BMW E46 radiator quick disconnect
Mishimoto prototype BMW E46 radiator quick disconnect

And a look at our aluminum end tanks. Both radiator mounting points and our Mishimoto stamped logo are incorporated into the tanks, combining factory-like fitment and subtle aesthetic appeal. Wonderful!

Mishimoto prototype E46 radiator end tank
Mishimoto prototype E46 radiator end tank

Mishimoto prototype E46 radiator end tank
Mishimoto prototype E46 radiator end tank

And finally, we have the biggest contributor to cooling performance, the radiator core itself. We spent a lot of time designing this core to provide optimal heat transfer for the E46. As many have found, the factory core, although thin, is actually quite dense in terms of external fins. This helps provide fantastic heat transfer, and many seem to have great success running the stock radiator in severe conditions.

Mishimoto prototype E46 radiator core
Mishimoto prototype E46 radiator core

So how are we planning to extract some extra efficiency from our core? Our prototype features a 41% increase in fin area, meaning the external fins that airflow can pass through. This was achieved by shortening the fin height and pitch in order to pack more fins into the same footprint. More fin surface area provides greater heat transfer contact points and should result in improved efficiency. We've also increased the capacity of the cooler, which is another way to improve coolant temperatures. The factory radiator utilizes a single row, measuring 30mm in width. Our radiator features a two-row design, each row measuring 16mm. This difference will provide a 18% increase in internal tube volume compared to the stock radiator.

Installing Our Prototype

Now that we had spent some time drooling over our prototype, it was time to install it in our test vehicle to check fitment of the various mounting points and connections.

A before shot below!

Stock BMW E46 radiator installed
Stock BMW E46 radiator installed

Stock BMW E46 radiator installed
Stock BMW E46 radiator installed

Out with the stock radiator and in went our prototype!

Mishimoto prototype E46 radiator installed
Mishimoto prototype E46 radiator installed

New Mishimoto BMW performance parts installed
New Mishimoto BMW performance parts installed

New Mishimoto BMW performance parts installed
New Mishimoto BMW performance parts installed

Everything bolted in perfectly, including the factory fan shroud. Our accurate measurements and diligence for perfection during the modeling process paid off with this one. Perfect fitment. Check!

You may have noticed some interesting hardware in the engine bay of our test vehicle. We've installed our sensor adapters in both the upper and lower radiator hoses in order to read radiator inlet and outlet temperatures. This will provide baselines to compare the stock radiator to our prototype.

Coming Up!

We have testing to do! Check back soon for results from our road-testing comparison of the stock radiator to our aluminum counterpart! If testing results are positive, this radiator will be a very nice addition to our line of BMW performance parts.

Thanks for reading!

-John

Interested in purchasing our E46 aluminum radiator? Check out our product page linked below!

Mishimoto BMW E46 Non-M Performance Aluminum Radiator!