The 7 Best VW Mk4 GTI 20th AE / 337 Mods & Performance Upgrades

The Volkswagen Mk4 GTI 20th Anniversary Edition and 337 Edition are some of the most popular vehicles for modifying and tuning - and for good reason. It's already quick right off the lot. It looks great and has ample room for storage and passengers. Whether you're looking to make your daily driver a bit quicker or to turn your GTI into a full-blown race car, UroTuning has the Mk4 GTI 20th AE mods and the knowledge to help you get where you need to be with your build!

MOD #1

Deciding which Mk4 GTI upgrades to prioritize can be difficult. To get the most bang for your buck, start with a Mk4 GTI 20th AE modded performance engine tune. Engine control unit (ECU) software will increase your Mk4 GTI's horsepower by modifying boost, fueling, ignition maps, and more. The dollar per HP gain is unmatched by any other Mk4 GTI 337 mods you could make to your engine. In addition to the engine, there are also tunes for your transmission. Automatic or Dual Clutch equipped cars can benefit from a Transmission Control Unit (TCU) tune to deliver increased power, higher RPM limit, faster shifts, optimized shift points, adjustable launch control, and additional transmission performance. Here are some of the top brands we'd recommend for Mk4 GTI power mods and tunes:

MOD #2

Your engine is essentially an air pump, so the more air you pump, the more power it will make! The intake system is heavily restricted from the factory to keep things quiet and optimized for low-end torque. Upgrading to a performance cold air intake will allow your engine to ingest more cold air, adding better throttle response, sounding great, and adding extra horsepower to your list of VW Mk4 GTI 20th AE mods.

MOD #3

Mk4 GTI upgrades for your exhaust system can unleash the full power of your engine. Aftermarket exhaust systems and upgrades provide a quicker, more efficient route for the exhaust gasses in your engine to escape, allowing the engine to breathe easier and make more horsepower. Because of fewer restrictions and better flow, the sweet sounds that a performance exhaust creates are a big reason you want to upgrade your exhaust system with VW Mk4 GTI 20th 337 mods.

MOD #4

If you’re ready to unleash more power with Mk4 GTI 20th AE mods, it’s time to upgrade your downpipe. This easy Mk4 GTI upgrade is a huge way to increase your engine’s horsepower. Reducing restriction and increasing airflow right after the turbo allows for significant power gains compared to the factory downpipe. Not only will power gains be plentiful you will also net some quite nice sound when upgrading the downpipe. It's a win-win for sure!

MOD #5

To achieve that lowered stance, there are three options among the best Mk4 GTI 20th 337 mods for suspension systems on the market today: lowering springs, coilovers, or an Air Ride System.

1. Mk4 GTI 20th AE Lowering Springs

Lowering springs are generally going to give you a more subtle drop. With springs, no adjustments can be made (unless you go with some Adjustable Lowering Springs).

2. Mk4 GTI 20th AE Coilovers

If you want to dial it in or adjust it fully just how you want, then adjustable coilovers may be the best fit.

3. Mk4 GTI 20th AE Air Ride System

Want to lay frame at the show but also want to be able to get over speed bumps without problems? Then go all in on a complete Air Ride System. Full-ride height adjustability at the press of a button! Your budget will ultimately decide your path, but lowering is among the best Mk4 GTI 337 mods!

MOD #6

Wheels can change the entire look of your car in an instant. At UroTuning, we firmly believe in getting new wheels after you lower your car. It’s practically an unwritten law! Upgrading your Mk4 GTI wheels gives you that curb appeal and the extra detail that proves you aren’t just another stock car on the road. Many options and price points for Mk4 GTI 20th AE modded wheels are available, so choose wisely.

MOD #7

Let's face it - when modding your Mk4 GTI, the first thought is always more power! But you can't forget that with all that extra GO, you also need some extra SLOW. OEM pads are a good choice, but there are better options among our selection of VW Mk4 GTI 20th AE mods!

UroTuning recommends, at minimum, a good set of Ceramic Brake Pads. These pads will shed less dust and have more bite for better stopping power. For even faster stops, upgrade rotors to slotted or drilled units. Want to go all in on stopping for VW Mk4 GTI 20th 337 mods? A Big Brake kit will give you the best braking setup and look good simultaneously!