The 5 Best Mods for the Volkswagen MK7 Jetta GLI

The MK7 Jetta GLI was the successor of the MK6 Jetta and was introduced in 2019 at the Chicago Auto Show. Under the hood, it features the same 2.0t TSI engine that is in the MK7 GTI. It puts down 217hp and 258lb-ft of torque out of the “box”. These numbers are quite impressive for a vehicle coming out of the factory, but enthusiasts find themselves asking, “How can it be faster?”. It is entirely possible to get an MK7 Jetta GLI to 350hp and more depending on how wild you’re looking to go.

Prior to Tuning: Ignition Coils & Spark Plugs

Before going into the mod guide below, let’s get into some important ignition components. When an engine is tuned, it typically yields more power, which requires more fuel. This leads to hotter temperatures in the combustion chamber. OEM spark plugs are sufficient for GLI’s on stock boost levels, but once tuned and running higher boost, they are prone to pre-detonation and engine misfires. This is due to increased combustion temperatures since OEM spark plugs can get too “hot”.

To anyone planning on running or currently running above stock boost levels, we recommend using 1-step colder spark plugs. 1-steps burn cooler which keeps engine temps down and prevents any knock, pre-detonation, or misfires. They’re relatively inexpensive and there is no reason not to run them because they keep your engine healthier, running better, and free from any misfires. However, if you plan on sticking with OEM spark plugs and your current ones are more than 15,000 miles old, we recommend replacing them before modding.

Here are our spark plug recommendations:

• OEM MK7 GLI Spark Plugs: use for all stock or modified GLI’s on stock boost. Recommended to be replaced every 40,000 miles.
• 1-Step Colder MK7 GLI Spark Plugs: any tuned GLIs running above-stock boost levels should be using 1-steps. Install them before tuning and replace them every 15,000-20,000 miles.
• MK7 GLI OEM Ignition Coils: ignition coils power the spark plugs, foiled ignition coils can cause engine misfires, rough idling, and so on. Recommended to be replaced every time spark plugs are replaced.

5 Best MK7 Jetta GLI Performance Upgrades

To make your Volkswagen Jetta GLI a 350hp machine, you will need to add these aftermarket mods:

1. ECU Tune
2. Intake
3. Downpipe
4. Performance Diverter Valve
5. Front Mount Intercooler (FMIC)

The above list is all basic bolt-ons and typically easy DIYs, except for the downpipe potentially. The brands below are OUR favorite on the market. This doesn’t mean you have to go with these, but please also do your research before purchasing a mod. Every enthusiast has different needs and wants when it comes to the performance of an engine.

1. ECU Tuning

Tunes are easily the biggest bang for your buck when it comes to modding an engine. The ECU that comes with the 2.0t engine out of the factory is conservatively tuned, meaning tuned for the everyday driver that wants comfort and reliability. However for enthusiasts, like ourselves, an ECU tune unleashes more power and efficiency that excites us. There are many benefits to getting an aftermarket tune:

• More hp and torque
• Custom engine maps
• Provides a cleaner burn
• Tailored to a driver’s habits
• Easy DIY

There are many brands that provide ECU tunes, whether it may be piggyback or flash tunes, but Burger Motorsports supplies our favorite tune by far. Its plug-and-play feature makes tuning easy and fun. They also offer up to 8 different tuning maps to satisfy all of the driving enthusiasts out there.

Burger Motorsports MK7 GLI JB4 Tuner

Price: $479.00 new | ~$350 Used

Horsepower Gains: 35hp – 90hp, depending on the supporting mods installed
Torque Gains: 45lb-ft – 90lb-ft, depending on the supporting mods installed

Buy Here: BMS JB4 $479

2. MK7 GLI High-Performance Intake Systems

This may be a heavily debated topic, but yes aftermarket intakes are worth the money. You’ll see minimal power gains without a tune, but you’ll have an awesome engine whoosh noise. Noise aside, if you are going for 300+ hp an intake is necessary to increase airflow to the engine, especially paired with a tune. The more air the engine brings in, the more pressure and combustion that is made, the more power the engine will release. The OEM units on the MK7 GLI are far more restrictive when it comes to airflow.

Our choice again for an aggressive aftermarket intake, would be Burger Motorsports’ elite intake. It features a huge 3″ tubing and increases airflow by a mile over the factory airbox. They offer the system with or without the turbo inlet, we highly suggest getting the inlet as well. The reason being is because the more factory parts that are replaced with aftermarket, less-restrictive, parts, the more air the turbo will receive.

Burger Motorsports MK7 GLI Elite Intake

Price: $329 (Without Inlet) – $379 (With Inlet)

Buy Here: BMS Elite Intake

Some people may say, “use a drop-in filter, it is far cheaper than getting a whole intake system and serves the same purpose.” A drop-in filter does not provide near the airflow increases that a full system would and the cool sound that comes along with it.

3. Jetta GLI High-Flow & Catless Downpipe Upgrades

Downpipes (DP) connect the turbo to the rest of an exhaust system. Factory downpipes have restrictive catalytic converters that produce higher back pressure and increase turbo lag, which in turn makes the turbo work harder. An aftermarket downpipe can significantly reduce back pressure, increase turbo spool, and increase power. If you don’t want to pony up all the money required for a turboback exhaust, this is a great alternative. Not to mention if you are wanting to push past Stage 1, most tunes require an aftermarket downpipe to do so.

A common question is catted downpipe or catless downpipe? A catted downpipe means that it has a high-flow catalytic converter, a catless means that it does not have a catalytic converter. A catless downpipe does produce a little more power and is louder, but the catted downpipes are still a huge improvement from the OEM. Also, removing the catalytic converter is technically illegal, but if you replace it with a high-flow catalytic converter, you will be legal. Depending on the state’s or country’s emission laws, will determine the best route for your downpipe. An ARM Motorsports downpipe paired with a tune will yield 60whp and 105wtq on a stock MK7 GLI turbo.

ARM Motorsports MK7 GLI Downpipe

Price: $397 (Catless) – $497 (Catted)
Buy Here: MK7 GLI Catted Downpipe

4. Aftermarket Diverter Valve

A performance diverter valve is advised after having the mods listed above installed. To some this may be a pointless mod, but as boost pressure increases, it is important to have a valve that is strong enough to hold the increased boost. The Go Fast Bits DV linked below holds up to 30lbs of boost and also creates a sharper throttle response. The factory valve is made of plastic parts, while the Go Fast Bits DV+ is made with metal parts to increase the reliability and strength of the valve.

Buy Here: Go Fast Bits DV+ MK7 GLI

5. GLI Performance FMIC – Front Mount Intercooler

Again, this is another mod that is heavily debated if it is necessary or not. Honestly, if you are wanting to stay at Stage 1, you probably won’t need an aftermarket intercooler. That doesn’t mean you shouldn’t want one, however. Factory intercoolers are meant for factory engines. Once you start tuning and adding more mods, the hotter the engine gets and the more air is brought in. The hotter the engine gets, the harder it is for the intercooler to cool the charged air in the engine. What ends up happening is heatsoak, which is defined as the hp killer, because your engine’s power will plateau and taper off the more it is driven in one run.

Aftermarket intercoolers are thicker and are way more efficient than factory intercoolers. An intercooler is not necessarily a performance mod, but it is an efficiency and reliability mod. The more things you get done to the engine, the lower the reliability is. Therefore, adding a more powerful intercooler increases the reliability, efficiency, and longevity of a modded engine.

Neuspeed MK7 GLI FMIC

Price: $829.95 (Stage 1) – $879.95 (Stage 2)

Buy Here: Neuspeed MK7 GLI Front Mount Intercooler

Conclusion – MK7 GLI Mods

A tune, a high-performance intake, a downpipe, and a diverter valve should yield a 350hp MK7 GLI at a rather inexpensive cost. Again, the brands listed above are the ones that provide the most value in OUR opinion. What does your MK7 GLI setup look like? Let us know in the comments below!

If you want to read more about Jetta’s, here is our write-up on The 5 Most Common Volkswagen MK7 Jetta Problems.