For those looking to enhance the sporty Golf even further, you might have already taken notice that we’re already on the case by way of cooling the charged air running through your 2.0T. A beefier intercooler is a start, but unfortunately that air doesn’t transfer into our intake manifold via osmosis. Naturally, ducting is still required.

When it comes to designing a new intercooler for any vehicle, it’s all about finding the right balance between core volume and flow. Knowing this, our engineer made some adjustments to our intercooler’s inlet and outlet sizes to maximize flow for stock and remapped tunes, while maintaining the right diameter for the MK7’s stock piping. However, for the best symbiotic relationship between intercooler and piping, Ye has been working on a new set of ducting specifically designed for maximum flow to and from our intercooler. Computer modeling can only get us so far, though. The first step in ensuring that our pipes work is making sure that they fit.

I wasn’t kidding when I said small packages. Peeking under the hood of any of the MK7 variants showcases VW’s ability to use a small space effectively. This all sounds great for producing tens of thousands of these vehicles, but the news isn’t so great when it comes to squeezing every drop of power out of your Golf or GTI. Yes, the space is used effectively, but that means smaller diameters on the current pipes, plenty of bends, and lightweight materials that aren’t exactly conducive to higher boost pressures.

So, what exactly does Ye have in mind for the new pipes? Overall, the plan is fairly simple. Increase the diameter where applicable, and update the construction for better durability. Let’s start with the hot-side piping, where increasing the diameter is the challenge.

You may remember back in our review on the stock system that the hot-side piping spent most of its time tapering from the turbo outlet diameter to its full size. Our hot-side pipe contains the diameter change within the silicone coupler before reaching the aluminum piping section to maximize the flow into the intercooler. We also added a few extra millimeters to the piping’s diameter, which effectively maxed out our build envelope.

When it comes to the cold-side, it’s a similar story. Our plan is to replace the plastic section of piping with mandrel-bent aluminum for a longer lasting connection from intercooler to intake manifold. We’re also planning on swapping out the rubber connections for more durable silicone couplers specifically designed to fit in the MK7’s tightly packed engine bay. More notable, we decided to ditch the air straightener that was molded into the stock cold-side pipe, adding a little extra attitude to your MK7.

Part of what makes these hot-hatches so hot is the optimization of the airflow throughout their turbocharged engines. After creating a tangible representation of our design plans, it’s clear that we intend to take that optimization even further. Stay tuned for an up-close look at our first production samples of these new designs, as well as seeing how well they perform on the MK7’s heavy hitting Golf R.

Typically, these new intercooler production samples show up like a wrecking ball. No, not like a scantily clad Miley Cyrus, but rather with size-doubling volume increases figuratively smashing the stock unit to smithereens. This time around, though, given our extremely tight build envelope, our new design might look mostly the same to some. We can assure you that much like the subtle outward appearance of the MK7 GTI and Golf R, looks can be deceiving.

The end tanks for our MK7 GTI’s intercooler have taken on a more supporting role than usual. If it wasn’t already mentioned enough, build space was a huge limitation when it came to this intercooler. We started from the ground up with these end tanks, creating a design that looks similar but with a sleeker profile for increased airflow. The first step was to abandon the plastic that originally made up the stock tanks and replace it with a sturdy aluminum construction. Since the typical use case for an upgraded intercooler is for vehicles touting extra boost, we wanted to make sure that these end tanks could handle the pressure.

Smooth and strong aren’t the only ways to describe these new end tanks. In the name of increased flow, we bumped up the size of the inlet and outlet sizes to 53.5 mm to allow this intercooler and the rest of the charged air system to breathe deeper while still being able to fit the stock couplers. Given the towering height of this core, we wanted to make sure that none of the bars were going to waste by adding a pair of diverters inside the hot-side tank.

Even though it’s a bit cramped in the front of the MQB platform, Ye was still able to make improvements over the stock core. For starters, the tube-and-fin layout is a thing of the past, and in its place is the more robust bar-and-plate configuration. This hearty construction might pack on a few extra pounds to the overall weight of the unit, but the gains help even that out.

Our new core might technically be shorter than the stock unit, however the updated construction combined with the more densely packed fins allowed Ye to give this new core two more rows of cooling power. While this intercooler inevitably gained some weight in the redesign process, it more impactfully bolstered in overall width. We didn’t think such a feat would be possible given our tight build envelope, but our engineer managed to give this design an 89% core volume increase over the stock intercooler.

On paper our shiny new production sample lives up to the challenge and is still able to cast a shadow on the original equipment. Even though we might not have been able to give this intercooler the tube-and-fin shattering size increases, the updates to the design will still yield cooler charged air for your VW or Audi, with the specifics on that soon to come.

What exactly makes us the little guy in this story, though? For the most part, it’s the placement of the stock unit, and that we’re still contending with the proverbial “intercooler sandwich” situation. Though, if you look through our last post, you’ll notice we’re not going into this entirely unprepared. We have some “Philly Specials” of our own, including that 89% increase in internal core volume while appearing about the same size as stock, and we plan to deliver quality with that design.

Part of that quality comes from our rigorous testing. We wanted to make sure that this new intercooling system could stand up to the best of the Volkswagen hot-hatch line and called in our star player, the MK7.5 Golf R, as our testing platform.

We started by getting the bench line of our intercooler’s performance over the stock equipment using single power pulls. This gives us a gauge on how much higher the power goes and how much lower the temperature drops. With our intercooler replacing the stock unit, we saw max gains of 14.2 whp and 12.2 wtq on the stock tuning, with an extra unit of torque when running on the full kit.

This jump in power isn’t just the result of dumb luck but rather the combination of innovative improvements we made over the stock unit. These tweaks consisted of clever diverters incorporated into our end tank casts that allowed for the efficient use of our entire bar-and-plate core, which resulted in a 23°F temperature drop over the stock core at the outlet. We expected an even more dramatic gap between inlet and outlet temperatures.

Now, I’m sure not many of you are like Dom Toretto and instead live your life more than just a quarter mile at a time. We took that into consideration. Heat-soak is unavoidable in the real world. Between heavy track use or heavy traffic, there will be variations in the airflow through the intercooler. We chose to simulate just that with our heat-soak test. For this stage, our engineer put the Golf R through five back-to-back pulls with only a few seconds in between to cool down. Even under these grueling conditions, our intercooler design was able to keep a steady outlet temperature where the stock unit would fluctuate approximately 20°F on the outlet temperatures.

Even with the tricky location, and all our restraints when it came to this project, our engineer persevered. The increased heat dissipation characteristics combined with the bump in power make for an iconic duo once you get behind the wheel of your MK7 Golf or related Audi, even more so with the addition of a tune.